close

Вход

Забыли?

вход по аккаунту

?

Effects of microwave energy as a source of supplemental heat on growth, behaviour, and reproduction of weaner pigs

код для вставкиСкачать
EFFECTS OF MICROWAVE ENERGY AS A SOURCE OF SUPPLEMENTAL
HEAT ON GROWTH, BEHAVIOUR, AND REPRODUCTION OF WEANER PIGS.
A Thesis
Presented to
The Faculty of Graduate Studies
of
The University of Guelph
by
ROBERT K. ACORN
In partial fulfilment of requirements
for the degree of
Master of Science
December, 1996
© Robert K. Acorn, 1996
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
1*1
National Library
of C anada
Bibliothdque nationale
du C anada
Acquisitions and
Bibliographic Services Branch
Direction d e s acquisitions et
d e s services bibtiographiques
395 Wellington Street
Ottawa, Ontario
K1A0N4
395, rue Wellington
Ottawa (Ontario)
K1A0N4
Your file
Our file
Votre reference
Notre r iffr e n c e
The author has granted an
irrevocable non-exclusive licence
allowing the National Library of
Canada to reproduce, loan,
distribute or sell copies of
his/her thesis by any means and
in any form or format, making
this thesis available to interested
persons.
L’auteur a accorde une licence
irrevocable et non exclusive
permettant a la Bibliotheque
nationale
du
Canada
de
reproduire, prefer, distribuer ou
vendre des copies de sa these
de quelque maniere et sous
quelque forme que ce soit pour
mettre des exemplaires de cette
these a la disposition des
personnes interessees.
The author retains ownership of
the copyright in his/her thesis.
Neither the thesis nor substantial
extracts from it may be printed or
otherwise reproduced without
his/her permission.
L’auteur conserve la propriete du
droit d’auteur qui protege sa
these. Ni la these ni des extraits
substantiels
de celle-ci
ne
doivent
etre
imprimes
ou
autrement reproduits sans son
autorisation.
ISBN
0-612-16613-9
Canada
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Name
Robert Kimball Acorn
D issertation A b stracts International is a rra n g e d b y b ro o d , g e n e ra l subject categories. Please select the o n e subject w hich most
n e a rly describes the content o f y o u r dissertation. Enter the c o rresp o n d in g fo u r-d ig it co de in the spaces p rovided.
SUBJECT TIRM
SUBJECT CODE
Subject Categories
THE HUM ANITIES AND SOCIAL SCIENCES
COMMUNICATIONS AND THE ARTS
A rchitecture.................................... 0 7 2 9
Art History.......................................0 3 7 7
G nem o
............ ................ 09 0 0
D o n ee.............................................. 03 7 8
Fine Arts ......................................... 03 5 7
Information Science,..................... 07 2 3
Journalism .......................................0391
library S c ien ce .............................. 03 9 9
Moss Communications..................0708
M usic
..... ............................. 0413
Speech Com m unication............... 04 5 9
T h e a te r............................................0 4 6 5
e d u c a tio n
G eneral ..........................................05 1 5
A dm inistration............................... 05 1 4
Adult an d C ontinuing...................05 1 6
A gricultural
...................... 05 1 7
A r t.................................................... 02 7 3
Bilingual an d M ulticultural
02 6 2
.............................. 0 6 8 8
B usiness
Community C o lleg e...................... 02 7 5
Curriculum an d Instruction
07 2 7
EoHy C hildhood.............................0 5 18
Elem entary
......................... 05 2 4
F in an ce..........................
0277
G uidance an d C o u n selin g
05 1 9
H ealth..............................................0 6 8 0
H ig h e r.............................................07 4 5
................ ..............0 5 2 0
History o f
Home Econom ics..........................0 2 7 8
Industrial.........................................0521
Longuage ond Literature ............ 0 2 7 9
M athem atics...................................0 2 8 0
M usic............................................... 0 5 2 2
Philosophy o l ................................. 0 9 9 8
P hy sical..........................................0 5 2 3
Psychology..................................... 0 5 2 5
R eo d in g
,............ ,........ .,..,.0 5 3 5
Rejigious....................
.....0 5 2 7
Sciences.........................................0 7 1 4
Secondary ...................................,.0 5 3 3
Social Sciences.............................. 0 5 3 4
Sociology o l ................................... 03 4 0
Special............................................. 05 2 9
Teocher T raining
................... 0 5 3 0
Technology......................................0 7 1 0
Tests ondM easurem ents.............. 0288
V ocational....................................... 0 7 4 7
LANGUAGE, LITERATURE AND
LINGUISTICS
lonauoge
G e n e ra l..................
0679
Ancient......................
0289
Linguistics.................................0 2 9 0
M o d ern.................................... 0291
Literature
G en eral.....................................0401
Classical................................... 0294
C om parative............................0 2 9 5
M edieval.................................. 0 2 9 7
M o d ern .................................... 0 2 9 8
A fricon
......................0 3 1 6
Am erican.................................. 0591
A sia n ........................................ 0305
Canodian (English}.................0352
Conodian (French) .................0 3 5 5
English......................................0593
G erm an ic.................................0311
Lotin A m erican........................ 0 3 1 2
Middle Eostern........................ 0 3 1 5
Romance ................................0313
Sfovic and East European
0314
PHILOSOPHY, RELIGION AND
THEOLOGY
Philosophy
......................0 4 2 2
Religion
G e n eral................. ................. 0318
Biblical Studies....................... 0321
C lergy......................................0 3 19
History o f ................................. 0 3 2 0
Philosophy o f ..........................03 2 2
Theology........................................ 04 6 9
SOCIAL SCIENCES
Americon Studies..........................0323
Anthropology
A rchaeology...........................0324
C ultural........................ ...........0326
Physieo!................................... 0 3 2 7
Business Administration
G e n eral................................. 0310
Accounting .............................0272
Banking................................... 0770
Management .........................0454
M orkcling............................... 0338
Canadian S tu d ies........................ 0385
Economics
G e n eral...................................0501
Agricultural.............................0503
Commerce-Business.............. 0505
Finance
........................ 0508
History..................................... 0 5 0 9
l a b o r ...................................... 0510
Theory..................................... 0511
Folklore..........................................0358
G eography.................................... 0366
G erontology................................. 0351
History
G en eral...................................0578
A ncient.....................................0579
M edieval................................0581
M o d e rn ................................... 0582
Block........................................ 0328
A focon ................................... 0331
Asia, Australia and Oceania 0332
C a n a d ia n ................................0334
European................................. 0335
Latin A m erican.................. ....0336
Middle Eastern.................
0333
.....................0337
United States
History of S cience.........................0585
Law.................................................. 0398
Political Science
G e n e ra l............................ ..... 0615
International Law and
Relations
..................0616
Public Administration.............0617
R ecreation......................................0814
Social W o r k .................................. 0452
Sociology
G e n e ra l................................... 0626
Criminology and Penology ...0627
D em ography.........................0 9 JB
Ethnic a n a Kocial Studies
0631
Individual and Family
S tu d ies.................................0626
Industrial and Labor
Relotions...............................0629
Public and Social W elfare.... 0630
Social Structure and
Development..................... 0700
Theory and M ethods..............0344
Transportation...............................0709
Urban ond Regional Plonning ....0999
0453
W omen's Studies ...........
THE SCIENCES A N D ENGINEERING
BIOLOGICAL SCIENCES
Agriculture
G e n e ro l..................................... 04 7 3
A gronom y................................ 02 8 5
Animol Culture ond
........................ .0 4 7 5
N utrition
Animal Pothology....................0 4 7 6
Food Science a n a
T echnology........................... 03 5 9
Forestiy a n a W ildlife............. .0478
Plont C u ltu re .............................04 7 9
Plant P ath o lo g y ....................... 04 8 0
Plant Physiology...................... 08 1 7
Ronge M an ag em en t...............07 7 7
W ood Technology.................. 0 7 4 6
Bl0lC * L « . l ..................................... 03 0 6
A n a to m y ...................................0 2 8 7
Biostatislics...............................03 0 8
B otany........................................03 0 9
Cell ......................................... 03 7 9
E cology.................................. ..0 3 2 9
Entomology............................. 03 5 3
G e n etics.................................... 03 6 9
lim nology..................................07 9 3
M icrobiofogy........................... 04 1 0
M olecufor..................................03 0 7
N euroscience........................... 03 1 7
O c ea n o g ra p h y
........0 4 1 6
Physiology ............................... 04 3 3
R adiation...................................0821
Veterinary Science...................07 7 8
Z oology
......
0472
Biophysics
G e n e ra l..................................... 0 7 8 6
M ed ic a l..................................... 07 6 0
EARTH SCIENCES
Biogeochemistry..............................04 2 5
Geochemistry ..............................0 9 9 6
G eodesy
................................. 0370
G eo lo g y ......................................... 0372
G eo p h y sics.................................... 0373
H ydrology.........................
0388
M ineralogy......................................0411
Paleobotany................................... 0 3 4 5
Poleoecology..................................0 4 2 6
Paleontology
........................ 0 4 1 8
Paleozoology.................................. 0985
Palynology ...........................
0427
Physical G eography
....... 0368
Physical O c ea n o g ra p h y ...............0 4 1 5
HEALTH AND ENVIRONMENTAL
SCIENCES
Environmental Sciences................0 7 6 8
Heolth Sciences
G e n e ra l.....................................0566
A odiology.................................0 3 0 0
C hem otherapy...................... 0 9 9 2
Dentistry................................... 0 5 6 7
E ducation................................. 0 3 5 0
Hospital M anagem ent............ 0 7 6 9
Human Developm ent..............0 7 5 8
Immunology............................. 0 9 8 2
Medicine and S u rg ery
0564
Mientol H e alth ...............
0347
N ursing............................
0569
Nutrition................................... 0 5 7 0
Obstetrics an d Gynecology ..0 3 8 0
Occupational Health ono
T herapy.................................0 3 5 4
O phthalm ology.......................0381
Pathology . Z . ........................ 0571
Pharm acology..........................04 1 9
Phorm ocy.................................05 7 2
Physical th e ra p y .....................03 8 2
Public H ealth .";.......................05 7 3
Radiology
.................. 05 7 4
R ecreation
................05 7 5
Speech Pathology................... 0 4 6 0
Toxicology............................... 0 3 8 3
Home Economics...........................03B6
PHYSICAL SCIENCES
Pure S ciences
Chemistry
G en eral.................................... 04 8 5
Agricultural.............................. 0749
A nalytical.................................0486
Biochemistry ...........................0 4 8 7
Inorganic..................................0488
N u clear.................................... 0 7 3 8
O rg an ic.................................... 0 4 9 0
Pharmaceutical........................ 0491
Physical.................................... 0494
Polymer.................................... 0495
R adiation..................
0754
M athematics................................... 04 0 5
Physics
G enerol.................................... 0 6 0 5
Acoustics.................................. 09 8 6
Astronomy ond
Astrophysics......................... 0606
Atmospheric Science.............. 0608
A tom ic......................................0748
Electronics ond Electricity
0607
Elementary Particles ond
High Energy......................... 0798
Fluid and Plasm o.................... 0 7 5 9
M olecular
..................0 6 0 9
N u clear.................................... 0 6 1 0
O p tic s.......................................0 7 5 2
Radiation..................................0 7 5 6
Solid S ta te ................................0611
Statistics.......................................... 0463
A p p lie d S ciences
Applied M echonics .................... 0 3 4 6
Computer S cience......................... 0 9 8 4
Engineering
G e n eral................
0537
A erospace
...................0538
Agricultural ............................ 0539
A utom otive......................
0540
Biomedical ............................. 0541
C hcm icol..........................
0542
C ivil.........................
0543
Electronics ond Electrical
0544
Hoot and Thermodynamics ...0348
Hydraulic.................................0 5 4 5
Industrial ................................. 0546
M o rin e .....................................0547
Materials Science...................0794
M echanical ........
0548
M etallurgy...............................0743
Mining ................................... 0551
N u c lea r.......................
0552
Packaging ...............................0549
Petroleum ................................0765
Sanitary ond M unicipal
0554
System Science....................... 0790
G eolochnoloay..............................0428
Operations Research
............0796
Plastics Technology...................... 0795
Textile Technology.........................0994
PSYCHOLOGY
G e n e r a l..........................................0621
B ehavioral
....................... 0384
C linico!...........................................0622
Developmental...............................0620
Experimental ................................,06 2 3
Industrial
....................................0624
Personality............................
0625
Physiological................................. 0989
Psychobiology............................... 0349
Psychometrics................................ 0632
S o c ia l..............................................0451
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Aulhor: Robert Kimball Acorn
THE UNIVERSITY OF GUELPH LIBRARY
AUTHORITY TO DISTRIBUTE THIS MANUSCRIPT THESIS
This thesis may be lent, or single copies made for purposes o f private study or research. AH other copying constitutes
inlringcmcnl o f copyright legislation. Aulhor and Department Chair/School Director sign in one o f the three spaces below.
Author
Chair/Director
without restriction
(b)
with the restriction that, for a period o f one
year, (dated from the dale of the thesis
defence), until
the w ritten approval o f lire Department
Chair/School D irector is required.
(c)
with tire restriction that, for a period o f one
year, (dated from the date o f tire thesis
defence), until
tire written approval o f lire author is
required.
The borrow er undertakes to give proper credit for any use made o f the thesis and to obtain the consent o f the author if it is
proposed to make extensive quotations.
Signature o f Borrower
Address
Date
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ACORN
UNIVERSITY
y jQ U H u P H
Robcrt Kimball
948 003 550
GRADUATE PROGRAM SERVICES
Animal and Poultry Science
MSc
CERTIFICATE OF APPROVAL (MASTER'S THESIS)
T he Examination Committee has concluded that the thesis presented by the above-named candidate in partial
fulfilment o f the requirements for the degree
M aster of Science
is worthy o f acceptance and may now be formally submitted to the Dean o f Graduate Studies.
Title:
Effects of microwave energy as a source of supplemental heat on growth,
behaviour, and reproduction of weaner pigs
****** * * * * * ** * * * * ** * * * * * ** * * * * ** * * * * * ** * * * * ** * * * * * ** * * * * ** * * * * * ** * * * * ** * * * * * ** * 4c********************
Chair, M aster's Examination Committee
u.
Advisor
HI.
IV.
Received by:
Date
&
J ^ jy g jjL n k jL V u Q . _______________
Dale:
a & r .
D£C 1 6 l99S-
for D ean o f Graduate Studies
rev. iv/96
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ABSTRACT
EFFECTS OF MICROWAVE ENERGY AS A SOURCE OF SUPPLEMENTAL
HEAT ON GROWTH, BEHAVIOUR, AND REPRODUCTION OF WEANER PIGS.
Robert K. Acorn
University of Guelph, 1996
Advisor:
Professor W.D. Morrison
Two experiments were conducted. Experiment 1 involved 60 female
weaner pigs. Experiment 2 involved 12 male weaner pigs. The pigs were
exposed to either microwave (2,450MHz; 17.9i7.9mW/cm2) or infra-red
radiation for 28 days. Growth, behaviour and reproductive abilities were
followed through to maturity. The microwave exposed (MW) females were
less active, and involved in fewer fights than the infra-red exposed (IR)
females during the exposure period. Compared to the IR males, the MW
males showed a slight but significant decrease in body weight until day 140
of the experiment. MW males also had a lower albumin:globulin ratio
throughout the duration of the experiment.
There were no other significant differences in growth rates, feed
consumption or conversion, blood chemistry, or behaviour. None of the
animals died or appeared to suffer due to the effects of microwave radiation.
Microwave energy is a safe and suitable source of supplemental heat for
weaner pigs.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ACKNOWLEDGEMENTS
I wish to thank my supervisor, Dr. W.D. Morrison, for his guidance,
support, and patience. I also wish to thank the other members of my
supervisory committee, Dr. L.A. Bate, Dr. I.J.H. Duncan, and Dr. T.
Widowski. They were all very helpful.
I thank the Atlantic Canada Opportunities Agency, the National
Research Council (Industrial Research Assistance Program), Maritime
Electric, and D'Ossone Canada Limited for their financial contributions to
this project.
I would also like to thank the staff of the University of Guelph Arkell
Swine Research Centre for all of their help. I especially thank Doug, Tom,
Nancy, and Vern. Thanks to the staff of Animal and Poultry Science, and
my fellow graduate students for assistance along the way.
I wish to thank my parents, Hilda Acorn and Kimball Acorn, for their
support and interest in my work.
Finally, I want to thank my best friend, and wife, Carolyn Acorn, for
her support, patience and willingness to help, no matter how stinky the
task.
i
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ABSTRACT
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
LIST OF PLATES
LIST OF TABLES
LIST OF FIGURES
INTRODUCTION .................................................................................................
1
LITERATURE REVIEW .....................................................................................
4
Properties of electromagnetic radiation................................................
5
Interaction of microwaves with m a tte r ................................................
8
Thermal versus athermal effects .......................................................... 11
Hematological and immunological e ff e c t s ............................................ 13
Behavioural effects.................................................................
16
Effects on embryos and fe tu se s..................................................................20
Effects on t e s t e s .............................................................................................26
MATERIALS AND METHODS ............................................................................29
Cage d e s ig n ...........................................................................................
30
Microwave generator d e s ig n .................................
32
Power density m easurem ents.................................................................
33
Supplemental heat for the control p i g s ................................................
34
ii
Reproduced with permission of the copyright owner. Further reproduction prohibited w ithout permission.
The environmental cham ber................................................................... 35
Experiment d e sig n .................................................................................... 36
Experiment 1 ................................................................................. 36
Statistical a n a ly s is........................................................................ 36
Experiment 2 .................................................................................
37
Statistical a n a ly s is........................................................................ 38
Care and sampling practices ................................................................. 39
F e e d ...................................................................................................40
Blood S a m p le s ............................................................................... 40
W eig h in g ......................................................................................... 41
V id eotap es.......................................................................................41
Sampling in terval.......................................................................... 43
Cleaning ......................................................................................... 44
G row ing............................................................................................44
Breeding ......................................................................................... 45
Farrowing .......................................................................................46
RESULTS ............................................................................................................... 47
Experiment 1: Females
...........................................................................48
Growth and feed d a ta .................................................................... 48
Blood d a t a ....................................................................................... 48
Reproduction data ........................................................................ 49
iii
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Behaviour d a ta ...............................................................................
50
Experiment 2: males ...............................................................................
51
Growth and feed d a ta ...................................................................
51
Blood d a t a ......................................................................................
51
Reproduction data ........................................................................ 52
Behaviour d a ta ............................................................................... 52
DISCUSSION AND CONCLUSIONS............................................................... 54
Experiment 1 .............................................................................................. 56
Experiment 2 .............................................................................................. 60
SUM M ARY............................................................................................................ 62
PLATES ................................................................................................................. 65
TABLES ........................
69
FIGURES ............................................................................................................... 76
BIBLIOGRAPHY................................................................................................
iv
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
103
LIST OF PLATES
Plate 1: Equipment used to expose pigs to infra-red or microwave radiation.
The cage is divided in half with the near side supplying infra-red
radiation and the far side supplying microwave radiation. All
equipment was located in an environmental chamber.
66
Plate 2: Microwave generator, waveguide, and dummy load used to supply
microwave radiation to the pigs during the experiment.
67
Plate 3: Equipment used to measure power density of the microwave
radiation in the cage.
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
68
LIST OF TABLES
Table 1: Some frequencies set aside for Industrial, Scientific, and Medical
uses. From WHO, 1981; and Repacholi, 1981.
70
Table 2: Sources of Background Radiation, and their respective power
levels on Earth. (From Repacholi, 1983).
71
Table 3: The penetration depth (cm) of several frequencies of
electromagnetic radiation in biological tissues with high and low
water contents. From Department of National Health and Welfare
Canada, 1977.
72
Table 4: Mean (± S.E.M.1) age and weight of the pigs in experiment 1 at
first estrus.
73
Table 5: Mean (± S.E.M.1) number of piglets per litter, average weight of
piglets, and percent male for the first litter bom from animals in
experiment 1.
74
Table 6: Mean (± S.E.M.1) volume (ml), concentration (106 sperm/ml),
progressive mobility (%), nonprogressive mobility (%), immobility (%),
and viability (%) of the semen collected from experiment 2.
75
vi
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
LIST OF FIGURES
Figure 1: Schematic diagram of the electromagnetic spectrum, (from Ford,
1968).
77
Figure 2: Schematic diagram illustrating wavelength, and the electric and
magnetic vectors of electromagnetic radiation. (Frum Health and
Welfare Canada, 1978).
78
Figure 3: Comparison of mean body weights (kg) of pigs during exposure to
microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red radiation
Experiment 1 involved female pigs; experiment 2 involved males. 79
Figure 4: Comparison of mean weight gain (kg) of pigs during exposure to
microwave radiation (2.45GHz, l7.9mW/cnr) or infra-red radiation
Experiment 1 involved female pigs; experiment 2 involved males. 80
Figure 5: Comparison of mean feed consumption (kg) of pigs during
exposure to microwave radiation (2.45GHz, l7.9mW/cm->) or infra-red
radiation. Experiment 1 involved female pigs. The data for
experiment 2 with male pigs are presented for the sake of
comparison. No statistical analysis has been performed on this
portion of experiment 2.
81
Figure 6: Comparison of mean feed:gain ratio of pigs during exposure to
microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 are
presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
82
Figure 7: Comparison of mean body weights (kg) of pigs, which had been
exposed to microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red
radiation for twenty-eight days, from the end of exposure period until
day 140 of the experiment. Experiment 1 involved female pigs;
experiment 2 involved males.
83
Figure 8: Comparison of mean albumin levels (gd) of pigs, which had been
exposed to microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure
period until day 140 of the experiment. Experiment 1 involved
female pigs; experiment 2 involved males.
84
Figure 9: Comparison of mean calcium levels (mmol/1) of pigs, which had
vu
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
been exposed to microwave radiation (2.45GHz, 17.9mW/cm2) or infra­
red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
85
Figure 10: Comparison of mean chloride levels (mmol/1) of pigs, which had
been exposed to microwave radiation (2.45GHz, lT.OmW/cm2) or infra­
red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
86
Figure 11; Comparison of mean globulin levels (g/1) of pigs, which had been
exposed to microwave radiation (2.45GHz, iT.OmW/cm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure
period until day 140 of the experiment. Experiment 1 involved
female pigs; experiment 2 involved males.
87
Figure 12: Comparison of mean glucose levels (mmol/1) of pigs, which had
been exposed to microwave radiation (2.45GHz, l7.9mW/cm2) or infra­
red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
88
Figure 13: Comparison of mean potassium levels (mmol/1) of pigs, which
had been exposed to microwave radiation (2.45GHz, 17.9mW/cm2) or
infra-red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
89
Figure 14: Comparison of mean progesterone levels (ng/ml) of pigs, which
had been exposed to microwave radiation (2.45GHz, n.&nW/cm2) or
infra-red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
90
Figure 15: Comparison of mean sodium levels (mmol/1) of pigs, which had
been exposed to microwave radiation (2.45GHz, n.SmW/cm2) or infra­
red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
91
Figure 16: Comparison of mean total protein levels (g/ 1) of pigs, which had
been exposed to microwave radiation (2.45GHz, l7.9mW/cm2) or infra­
red radiation for twenty-eight days, from the beginning of the
viii
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
exposure period until day 140 of the experiment. E xperim ent 1
involved female pigs; experiment 2 involved males.
92
Figure 17: Comparison of mean albumin:globulin ratios of pigs, which had
been exposed to microwave radiation (2.45GHz, l7.9mW/cm2) or infra­
red radiation for twenty-eight days, from the begin n in g of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
93
Figure 18: Comparison of mean sodium:potassium ratios of pigs, which had
been exposed to microwave radiation (2.45GHz, 17.9mW/cm2) or infra­
red radiation for twenty-eight days, from the beginning of the
exposure period until day 140 of the experiment. Experiment 1
involved female pigs; experiment 2 involved males.
94
Figure 19: Comparison of mean percent of time spent lying alone during
exposure to microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red
radiation. Experiment 1 involved female pigs. The data for
experiment 2 with male pigs are presented for the sake of
comparison. No statistical analysis has been performed on this
portion of experiment 2.
95
Figure 20: Comparison of mean percent of time spent lying in a huddle
during exposure to microwave radiation (2.45GHz, 17.9mW/cm2) or
infra-red radiation. Experiment 1 involved female pigs. The data for
experiment 2 with male pigs are presented for the sake of
comparison. No statistical analysis has been performed on this
portion of experiment 2.
96
Figure 21: Comparison of mean percent of total time spent lying during
exposure to microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red
radiation. Experiment 1 involved female pigs. The data for
experiment 2 with male pigs are presented for the sake of
comparison. No statistical analysis has been performed on this
portion of experiment 2.
97
Figure 22: Comparison of mean percent of time spent with head in feeder
during exposure to microwave radiation (2.45GHz, 17.9mW/cm2) or
infra-red radiation. Experiment 1 involved female pigs. The data for
experiment 2 with male pigs are presented for the sake of
comparison. No statistical analysis has been performed on this
portion of experiment 2.
98
Figure 23: Comparison of mean percent of time spent performing other
ix
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
activities during exposure to microwave radiation (2.45GHz,
^.SmW/cm2) or infra-red radiation. Experiment 1 involved female
pigs. The data for experiment 2 with male pigs are presented for the
sake of comparison. No statistical analysis has been performed on
this portion of experiment 2.
99
Figure 24: Comparison of mean number of drinks per pig during exposure
to microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red radiation.
Experiment 1 inv olved female pigs. The data for experiment 2 with
male pigs are presented for the sake of comparison. No statistical
analysis has been performed on this portion of experiment 2.
100
Figure 25: Comparison of mean number of minutes spent fighting during
exposure to microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red
radiation. Experiment 1 involved female pigs. The data for
experiment 2 with male pigs are presented for the sake of
comparison. No statistical analysis has been performed on this
portion of experiment 2.
101
Figure 26: Comparison of mean number of fighting bouts during exposure
to microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 with
male pigs are presented for the sake of comparison. No statistical
analysis has been performed on this portion of experiment 2.
102
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
INTRODUCTION
1
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
In northern climates, energy costs are a significant factor in the
design and operation of animal housing. In the swine industry, it is
necessary to supply a great deal of supplemental heat to young pigs. Up to
sixty-five percent of the total energy consumption in a farrowing - weaning
operation may be used for heating (Barber et al, 1989). Therefore, a cost
effective and efficient method of delivering heat energy to pigs would be
useful. In addition, airborne pollutants, such as dust and gasses can pose a
health risk to both animals and humans. Bundy and Hazen (1975) reported
that up to ninety-five percent of the dust in swine buildings is of a particle
size considered damaging to the lungs. A cleaner air environment would be
very beneficial.
Morrison et al (1986) suggested that microwave energy might be used
as a comfortable source of heat for food-producing animals. It is possible to
design a housing system in which the pigs are warmed by microwaves, but
the walls, floor, ceiling, and air do not absorb much energy. This would
allow the bam to be maintained at a lower temperature, thereby reducing
heating costs. Also, a higher ventilation rate could be used to reduce air
pollutants, since the pigs would no longer be dependent on warm air to
reduce heat loss.
Braithwaite et al (1993) briefly described some uses of microwave
energy as a heat source for incubating eggs, warming chicks and weaner
pigs, and rewarming hypothermic piglets and lambs. However, further
2
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
work needs to be done to determine long term effects of microwave
radiation. The purpose of this study was to determine whether microwave
radiation has a significant effect on growth, behaviour, or future
reproductive ability of weaner pigs.
3
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
LITERATURE REVIEW
4
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Microwave energy is a form of electromagnetic radiation. There is a
great deal of literature describing the properties of electromagnetic
radiation and its effect on biological systems (World Health Organization,
1981; Department of National Health and Welfare Canada, 1978; Schwan,
1970; USAF, 1985; Durney e t al, 1978; Tyler, 1975; NCRP, 1986;
Johnson and Guy, 1972; Michaelson, 1970; Michaelson and Lin, 1987;
Jauchem, 1993; Chou et al, 1992, D'Andrea et al, 1979). The following is a
review of some of this information.
Properties of electromagnetic radiation
Electromagnetic radiation can be described by two different theories.
According to one theory, the radiation is composed of particles called
photons, which contain a set quantity of energy, and travel in a straight
line. In the other theory, radiation is described as a wave phenomenon.
According to this theory, the propagation of radiation is similar to the
movement of waves caused by dropping a stone in water. In quantum
physics, matter and energy are identical, so the wave and particle theories
are consistent with each other.
The electromagnetic waves are composed of electric fields (E) and
magnetic fields (H), which oscillate perpendicular to each other, and to the
direction of travel (Durney et al, 1978). The fields oscillate in time from a
maximum positive value to a maximum negative value. The distance from
5
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
a point on one wave to the corresponding point on the next wave is the
wavelength. The number of peaks that pass a given point in space per
second is the frequency, and is measured in cycles per second, or Hertz (Hz).
The amount of energy in a photon or wave is a function of its
frequency. As the frequency of the photon or wave increases, so does its
energy level. Radiation with a frequency greater than 2.4 x 1015 Hz is
energetic enough to ionize atoms (Dept. National Health and Welfare
Canada, 1977). This corresponds to a photon energy of 12 electronVolts (eV)
(WHO, 1981). Microwave energy is from the non-ionizing portion of the
electromagnetic spectrum. The maximum quantum energy of a microwave
photon is 1.2 x 10'3 eV at a frequency of 300 GHz, which is well below the
level necessary for ionization (Stuchly, 1983).
In free space, electromagnetic radiation travels at approximately
2.998x10® nVsec, but will slow down when it enters a denser medium. The
velocity in a given medium depends on the permittivity and permeability of
that medium (Michaelson and Lin, 1987).
The frequency, velocity, and wavelength are related by the following
formula:
X= c/f
where:
X is the wavelength (meter^cycle),
c is the speed of light (2.998 x 108meter ^second),
6
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
f is the frequency (cycle^second).
The electromagnetic spectrum has been divided into different regions,
according to the properties and uses of the radiation in each region. Several
frequencies have been designated for use in industrial, scientific, and
medical purposes, by the World Administrative Radio Conference, Geneva
(1979). These frequencies are called ISM frequencies and are listed in Table
1. The World Health Organization (WHO, 1981) has designated that
radiation with a frequency range of 300 MHz to 300 GHz (1 m to 1 mm
wavelength respectively, in free space) be referred to as microwave
radiation.
Microwave energy can be transmitted by several means. It can be
radiated into free space by an antenna, or its direction of travel can be
controlled by the use of a waveguide. A waveguide is a partially or
completely enclosed metallic structure with the electromagnetic radiation
confined within it (Michaelson and Lin, 1987). If a waveguide is used, the
transverse dimension of the waveguide must be less than the wavelength of
the radiation, or a multimode cavity may be created (WHO, 1981).
The energy level of electromagnetic radiation may be measured in
terms of the electric field strength (Voltameter, V/m) and the magnetic field
strength (Amps/meter, A/m). At distances greater than one wavelength
from the source of radiation the electric and magnetic fields are in phase,
7
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
and the field strengths combine to give a power density, which is usually
measured in Volt-amps per square meter (VA/m2), Watts per square meter
(W/m2), milliwatts per square centimetre (mW/cm2), or microwatts per
square centimetre (pW/cm2) (NCKP, 1986).
All bodies that can absorb
energy can also radiate it (Repacholi, 1983). Therefore, the earth, the
atmosphere, and plants and animals can be a source of background
radiation. To calculate the energy level emitted by a body for a given
frequency, the following formula is used:
S = 0.3 ( f / 300 )3* T / 300 pW/cm2
(Repacholi, 1983)
where:
S is the power density (pW/cm2) of the background radiation,
f is the frequency in GHz,
T is the temperature of the body in Kelvin.
Table 2 lists several sources of background radiation for frequencies below
300 GHz, along with their respective power levels.
Interaction of microwaves with m atter
When microwave radiation encounters matter it may be reflected,
refracted, transmitted or absorbed. The proportion of energy which
undergoes each process depends on the physical properties of the matter
8
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
and the frequency of the radiation (WHO, 1981).
Johnson and Guy (1972) discussed some of the difficulties associated
with understanding how electromagnetic fields interact with biological
tissues. They stated that it is customary to measure the incident power
density in an exposure chamber without the subject present. When the
subject is introduced into the field, several complications arise. There is an
unknown amount of scattered, transmitted, and internally reflected power,
which will affect the amount of energy absorbed by the subject. The size,
shape and surroundings of the subject will all affect the amount of energy
absorbed.
The dielectric constant and the loss tangent are properties of matter
which are important in determining the fate of the radiation. The dielectric
constant is a measurement of the ability of a material to support an electric
field, and this changes with the frequency of the incident field. The loss
tangent of a material is a way of characterizing the electrical losses within
it (Tranquilla, 1994). If the dielectric constant is high, then the energy is
slowed down as it passes through the load. The velocity of the wave
changes according to the following formula:
vac 1/Ve
(Tranquilla, 1994)
where:
v = velocity of wave (meter^second),
9
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
e = dielectric constant of the medium (Farads/meter).
For example, the dielectric constant of water is 80 at 2450 MHz; therefore,
the velocity of electromagnetic energy in water is approximately V9th of its
velocity in space, and its wavelength is reduced accordingly. If the loss
tangent is high, then energy is attenuated as it passes through the matter.
If the loss tangent is low, for example 0, the material would be transparent
to microwaves. That is, there would be no energy loss, and no heat
generation as the radiation passes through the m atter (Tranquilla, 1994).
Penetration depth, or skin depth, is the distance an electromagnetic
field will penetrate a material before the field strength drops to 1/e of its
initial value, where e = 2.7183, (the base of the natural logarithm)
(Tranquilla, 1994). Biological tissues with a high water content, such as
m uscle and skin, have a high dielectric constant and high loss tangent.
Therefore, microwave radiation is readily absorbed and those tissues are
warmed. Conversely, tissues such as bone and fat which have a low water
content, have lower dielectric constants and loss tangents. These tissues do
not absorb as much microwave energy. Table 3 gives a list of the
penetration depths of several frequencies of electromagnetic radiation in
biological tissues with high and low water contents.
Energy is absorbed when the oscillating fields of the microwave
radiation cause polar atoms or m olecules such as water or amino groups of
10
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
proteins to flip back and forth with the frequency of the radiation, in an
attempt to align with the oscillations of the electrical field. This vibration
causes heat production through frictional energy loss (Tranquilla, 1994).
The amount of energy which is absorbed by the material is measured
in terms of energy absorbed per unit mass, and is called the specific
absorption rate (SAR). It is usually measured in terms of watts per
kilogram (W/kg), m illiwatts per kilogram (mW/kg), or m illiwatts per gram
(mW/g).
Thermal versus athermal effects
Changes caused in biological system s by microwave radiation are
often divided into two categories: thermal effects, and athermal effects.
Thermal effects are those effects which can be linked to an increase in body
temperature. Athermal effects, or field-specific effects, are effects not
attributable to changes in temperature when electromagnetic radiation is
imposed on or absorbed by a medium or system (NCRP, 1986). It is often
difficult to distinguish between the two effects, due to difficulty in
m easuring minute temperature change in a biological system. Also, an
effect may be caused by a localized heating of tissue which can not be
accomplished through conventional heating methods.
H eller and Teixeira-Pinto (1959) proposed that the orientation and
pearl-chain formation they observed in subcellular particles and
11
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
microorganisms were due to an athermal effect of microwave radiation.
However, other investigators (Schwan, 1970, and Michaelson, 1970) could
only duplicate those results at power densities which caused a significant
temperature rise, and therefore would probably not be found in practical
applications involving biological m aterials.
In an experiment conducted by Saffer and Profenno (1992)
E scherichia coli bacteria were exposed to microwave radiation in the 2 GHz
to 4 GHz range. The exposed bacteria showed a 3% to 5% increase of (3galactosidase activity over sham-exposed bacteria. The temperature of both
groups of bacteria was m aintained w ithin 0.1°C of each other. The authors
suggested that the differences were not due to a field specific effect, but
rather to a thermal effect caused by the particular energy deposition of
microwaves into E. coli culture, because the effect was seen over such a
wide range of frequencies.
Many of the following articles reviewed here attempt to explain their
findings in terms of thermal or athermal effects. Unfortunately, it is very
difficult to say with certainty which mechanism has caused the noted
effects. It is also important to note that the mere presence of an effect does
not necessarily indicate a harmful or beneficial result. Jauchem (1993), in a
review of scientific, medical and lay literature about radiation effects, points
out many discrepancies in articles linking radiation with health effects, and
im plies that some claims of electrom agnetic radiation effects are
12
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
exaggerated.
Hematological and immunological effects
Budd and Czerski (1985), in a review of the effects of electromagnetic
radiation on m am m alian immunity, conclude that reports of alterations of
the immune system are often contradictory, and there is insufficient
evidence to indicate that electromagnetic radiation effects on the hum an
immune system are a health hazard.
In an experiment to determine the systemic effects of localized
hyperthermia, Yerushalmi et al (1984) heated the rectum of rabbits to 42.9 43.2 °C using a coaxial probe from a 2.45 GHz, 100 Watt generator. The
blood glucose levels were measured and compared to those from control
rabbits. The authors concluded that the temporarily elevated glucose levels
found in the treated animals resulted from a thermal effect of the
microwave treatment.
Czerska et al (1992) exposed human lymphocytes in vitro to 2450
MHz continuous wave and 2450 MHz pulsed wave microwaves to determine
whether there is a difference in the lymphoblastoid transformation. A
control group was warmed by conventional heating. The cells were exposed
for 5 days at non-heating (37°C) and various heating levels (0.5, 1.0, 1.5,
and 2°C temperature increases). The pulsed exposures involved 1 psecond
pulses at 100 - 1000 pulses per second. The average specific absorption rate
13
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
levels were the same for the pulsed and continuous exposures, i.e. 1 W/kg 12.3 W/kg. The authors concluded that conventional and continuous wave
heating do not differ in their effect on lymphoblastoid transformation.
However, the pulsed wave exposures cause significant enhancement of
lymphoblastoid transformation. In attempting to explain the differences,
the authors note that pulsed exposures produce a larger rate of change of
temperature; however, not enough information is available to determine a
mechanism for the effect.
Braithwaite et al (1991a) exposed 22 one-week old broiler chicks to
either a 250 watt infrared bulb or a microwave generator delivering 13
mW/cm2 of 2.45 GHz radiation. The amount of tim e the heat sources were
on was controlled operantly by the chicks. There were no significant
differences between the two treatm ents in terms of packed cell volume, total
plasma protein, bursa weight, spleen weight, heterophil:lymphocyte ratio,
corticosterone level, body weight, or feed:gain ratio. The microwave exposed
chicks requested significantly fewer minutes of heat than the chicks under
infrared lamps. The authors suggest that operantly controlled microwave
energy as a heat source has no detrimental effects in terms of stress or
reduction in performance.
In an experiment to evaluate hematological and immunological effects
of long-term 2450 MHz continuous wave radiation on rabbits, McRee et al
(1980) exposed 4 rabbits 23 horns per day for 180 days. Four other rabbits
14
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
were sham-exposed. The power density ranged from 7 - 1 0 mW/cm2 over
the rabbits' bodies. Eosinophil percentage, albumin and calcium levels were
significantly lower in the exposed rabbits. Thirty days after termination of
exposure the albumin/total globulin ratio was significantly decreased in the
exposed rabbits. Also, the exposed rabbits had an increase in the
myeloid/erythroid ratio in the bone marrow of the sternum. The
lymphocytes from the exposed rabbits also showed a significant suppression
in responsiveness to pokeweed mitogen, but not to phytohemagglutinin or
concanavalin A. Eosinophil levels returned to normal 30 days after
exposure.
D'Andrea et al (1979) exposed adult male rats to 2,450 MHz
continuous wave radiation for eight hours a day, five days a week for a total
of 640 hours. Blood samples were taken at the beginning and end of the
experimental period as well as at weeks 2, 6, 10, and 14. No significant
differences which could be attributed to treatm ent were found in red blood
cell counts, white blood cell counts, haemoglobin levels, haematocrit (%),
polymorphic neutrophils (%), or lymphocytes (%), with the exception of red
and white blood cell counts during week 6. During week 6 the microwave
exposed anim als had a significantly lower red blood cell count and a
significantly higher white blood cell count. Also the total free sulfhydryl
levels were significantly higher in the microwave exposed group during
weeks 6 and 10. The authors believe these differences are due to sampling
15
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
errors or some other artifact since the effects are transitory, and the levels
of the sham-exposed group also changed.
Lu et al (1977) performed an experiment, in which rats were exposed
to 0, 1, 5, 10, or 20 mW/cm2 of 2450 MHz radiation for 1, 2, 4, or 8 hours.
They did not find any change in growth hormone levels. In rats exposed at
20 mW/cm2 for four or eight hours, the serum thyroxine levels were reduced.
Serum corticosteroid levels were also reduced in rats exposed at 20 mW/cm2
for eight hours. They also found a significant correlation between rectal
temperature and corticosteroid levels in sham exposed rats. The authors
state that the elevation of body temperature was the most influential
parameter measured. This implies that the changes noted were due to body
temperature changes rather than a radiation effect.
Behavioural effects
In a review of the health aspects of microwave exposure, the
Department of Health and Welfare Canada divide studies of the behavioural
effects of microwaves into three categories: sensory detection, strong
perturbations, and weak perturbations (Health and Welfare Canada, 1978).
An example of sensory detection is the effect known as "microwave
hearing", which is caused by low-power density, pulsed radiation (Health
and Welfare Canada,1978). Strong behavioural perturbations are caused by
a high dose rate (eg. 9mW/g in rats) and are manifested by work stoppages
16
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
or convulsions (Health and Welfare Canada,1978). Weak behavioural
perturbations include changes in activity levels and learning ability (H ealth
and Welfare Canada,1978).
Morrison et al (1986) conducted an experiment in which chicks were
operantly conditioned to turn on a heat source (either microwaves or
infrared radiation). The behaviour of the chicks was compared to chicks
Tinder continuous infra-red heat, and no supplemental heat. Chicks exposed
to microwave radiation requested significantly fewer minutes of
supplemental heat than the infrared exposed chicks. The authors speculate
that this may be due to either more efficient use of the energy supplied, or a
negative reward associated with the microwaves. However the sim ilarity
between the growth rates of the microwave exposed and the infra-red
exposed chicks suggests the former explanation (Morrison et al, 1986). The
authors found that the chicks were able to recognize microwave radiation as
a reward in the form of heat, and the microwave radiation did not appear to
inhibit the chicks' ability to perform a trained task.
John O. deLorge (1984) exposed five rhesus monkeys to 225 MHz
continuous wave and 1.3 GHz & 5.8 GHz pulsed wave radiation to
determine the threshold power density which will affect the performance of
the monkeys in pressing levers to receive a food reward. The monkeys were
sham- exposed or irradiated on alternate days. The author determined
power density thresholds for each of the frequencies, but also determined
17
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
that the colonic temperature increase of the monkeys was a better predictor
of behavioral disruption than either incident power density or specific
absorption rate.
In a study of the effects of long-term low-level exposure to
radiofrequency radiation, Johnson (Johnson et al, 1983, and USAF, 1985)
found no significant alteration of activity, defecation, or urination in rats
exposed to 2450 MHz pulsed wave radiation at a power density of
0.48mW/cm2 for up to 25 months.
Chemovitz et al (1975) assigned 60 pregnant mice to a factorial
experiment, with the following treatments: control, microwave exposed
(2450 Mhz at 38 mW/g for 600 seconds), cortisone injection (5 mg), and
microwave exposed with cortisone injection. The mice were treated on the
14th day of gestation. At 38 days of age, the pups began training in a
Lashley-III maze, modified for swimming. After the maze was learned the
mice were required to learn the reversal three tim es. Analysis of variance
did not reveal any significant difference between the control and microwave
exposed animals. Those mice that received cortisone learned significantly
more slowly than those that did not, indicating that the experiment was
sensitive enough to pick up differences in learning ability. The authors
acknowledge that th is maze test may not be ideal for testing the effects of
microwave radiation on learning ability.
Shandala et al (1977) exposed albino rats to 2375 MHz radiation at
18
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
power densities of 10 jiW/cm2 and 50 pW/cm2, seven hours per day for 90
days. The exposed animals were compared with controls. Avoidance
reactions, open-field exploratory activity, and threshold of electrical shock to
the feet were measured on days 10, 20, 30, 60 and 90. The authors found
an initial phase of central nervous excitation on day 10, followed by
inhibition at day 90. The rats exposed to the higher density radiation
showed more inhibition than both the controls and the lower density
exposure rats.
DeW itt et al (1987) studied the behavioural effects of chronic
exposure to 2450 MHz radiation by exposing Long-Evans rats to a power
density of 0.5 mW/cm2 for 7 hours per day, for 90 days. Measurements were
taken for shock sensitivity, open-field test, shuttlebox avoidance and
schedule-controlled behaviour. N either the microwave nor the sham
exposed anim als were consistently more efficient at performing the schedule
controlled behaviour. The microwave and sham exposed rats did not differ
significantly in their responses to the shock sensitivity tests, the open-field
tests, or the shuttlebox training tests.
D'Andrea et al (1979) exposed rats for 8 hours per day, 5 days per
week to microwave radiation. The activity of irradiated and shamirradiated rats were measured by the number of wheel rotations in an
activity cage over a 12 hour period, and by the use of stabilimetric platforms
which measured lateral movements for one hour immediately after
19
with permission of the copyright owner. Further reproduction prohibited without permission.
exposure. The authors found no differences in the amount of activity on the
wheel, but the exposed rats showed a significant decrease in activity as
measured by the stabilimetric platform. The authors suggest that the
relative inactivity of the exposed rats on the stabilimetric platform is due to
the rat's attempt to deal with overheating induced by the microwaves. They
also suggest that no difference was found in wheel rotations because the
rats had time to cool off, and resume normal activity.
Roberti et al (1975) exposed rats to 0.3 - 0.9 GHz radiation and
measured the spontaneous motor activity level and athletic performance.
No significant differences were found between experimental and control
rats. The authors attempted to m aintain both groups of rats at equal body
tem peratures.
The conflicting results of some experiments comparing behaviour of
microwave exposed and control anim als may be due to hyperthermia rather
than a direct effect on the central nervous system.
Effects on embryos and fetuses
Berman et al (1978) exposed 318 pregnant mice to 100 minutes of
2450 MHz radiation daily, at power densities of 3.4 mW/cm2, 13.6 mW/cm2,
14 mW/cm2, and 28 mW/cm2, and compared them to 336 sham-exposed
pregnant mice. All mice were killed on day 18 after breeding, and the
uterus and fetuses were examined. They found no difference between
20
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
pregnancy rates, or means of live, dead and total fetuses per litter.
However, the litter mean live fetal weight of the group exposed at 28
mW/cm2 was significantly reduced when compared to the shams. Also,
cranioschisis occurred significantly more frequently in irradiated subjects,
than in sham exposed subjects. The SAR in this study ranged from 1.2-13.3
J/g. The dams experienced only a very slight rectal temperature increase
when exposed to 28 mW/cm2. All other dams experienced a slight
temperature decrease during exposure or sham exposure. It is possible that
a localized heating effect occurred which caused the differences noted.
In a study involving pregnant rats, Berman et al (1981) exposed 70
animals to 28 mW/cm2 of 2450 MHz radiation for 100 minutes per day on
days 6 through 15 of gestation. The dams were killed on the 21st day of
pregnancy, and the uterus and fetuses were compared to those of 67 sham
exposed pregnant fem ales. There were no significant differences between
microwave-irradiated and sham-irradiated animals. Pregnancy rates, mean
number of live, dead, and resorbed fetuses were similar for both groups.
Also, live fetal weight, and types and incidences of several terata were
similar. It was concluded, in this study, that microwave radiation levels
which do not raise the body temperature of the dam to a level likely to kill
the dam, is not likely to cause teratogenesis.
In 1982, Berman et al (1982a) conducted an experiment to determine
whether microwave radiation caused stunted growth in mice offspring after
21
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
in utero exposure to 2450 MHz radiation at a power level of 28 mW/cm2 for
100 m inutes per day from days 6 through 17 of gestation. A toteil of one
hundred mice were used in the study. Fifty were exposed to the microwave
radiation and fifty were sham-irradiated (controls) in two replicates. H alf of
the litters were examined after hysterotomy on day 18 of gestation. The
rest were bom naturally. No significant differences were found in litter
sizes, or number of alive or dead fetuses between exposure groups at day 18
of gestation, at birth, or at day 7 of age. The microwave exposed litters had
significantly fewer sternal ossification centres than their sham exposed
counterparts. Also, the microwave exposed group had a significantly lower
body weight at day 1 and day 7 after birth. The authors conclude by stating
that microwave radiation during gestation causes retarded growth of pups
and stunting persists to maturation. There is no indication given that the
temperature of the exposed mice was monitored, or that the sham-exposed
mice were maintained at a sim ilar temperature. It is possible that the
noted effects were due to an elevation of the dam's body temperature.
Berman et al (1982b), exposed pregnant Syrian ham sters to 2450
M Hz radiation at 20 mW/cm2 and 30 mW/cm2 for 100 m inute s daily on days
6 through 14 of gestation. These were compared to sham irradiated
ham sters. The ham ster fetuses exposed to 20 mW/cm2 showed no
significant differences with the control anim als in fetal survival, body
weight, or numbers of sternal ossification centres. The fetuses exposed to
22
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
30 mW/cm2 showed no significant difference w ith controls in number of live
fetuses or total number of implantations. However, there were significantly
more resorbed or dead fetuses and a decreased fetal body weight in those
fetuses exposed to the higher microwave power level. The body temperature
of the dams exposed to 20 mW/cm2 and 30 mW/cm2 rose an average of 0.4"C
and 1.8°C above that of the sham exposed controls, respectively. This
increase in body temperature may explain the differences found in the
group exposed to the higher power level.
Davidson et al (1976) exposed day-old chicks to microwave radiation
of an unreported frequency in a series of four experiments. The first
experiment determined a lethal dose of microwave radiation of 800 wattseconds of energy. The second experiment exposed 162 chicks to 49% and
74.5% of the lethal dose determined in the first experiment. The survivors
of both exposure levels had a significantly lower weight gain over the next
three weeks than the controls. In the third experiment, 110 day-old female
chicks were exposed to 800 watts of power for 4.5 seconds. The treated
birds had a lower rate of mortality up to m aturity than the control group,
but egg production levels were similar. There was no difference in
hatchability or fertility between the two groups. Experiment four was
sim ilar to experiment three, except that a different strain of chicks was
used. In this case the chicks were raised to twenty weeks, and no mortality
differences were found between controls and microwave exposed animals.
23
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Cheraovitz et al (1975) exposed 80 mice to, either 2450 MHz
radiation at 38 mW/g, or sham irradiation (controls) for 600 seconds on the
11th, 12th, 13th, or 14th day of gestation, in a factorial experiment. H alf of
the dams from each exposure group were also injected with 5 mg of
cortisone as a teratogen. Fetuses were examined on the 19th day of
gestation for gross structural abnormalities. An analysis of variance did not
indicate that exposure to microwave radiation was a significant cause of
fetal abnormalities, and the exposure did not result in higher m ortality or
morbidity rates. The cortisone treatm ent, however, did appear to cause
significantly higher incidences of fetal structural abnormalities, m ortality
and morbidity.
Hamrick and McRee (1975) exposed Japanese quail embryos in the
shell to 2.45 GHz radiation at an incident power density of 30 mW/cm2 for
24 hours. The microwave exposed eggs were maintained at a temperature
of 37°C. The control eggs were housed in an incubator at 36°C. No
significant differences were detected between the two treatm ents for the
following parameters: weight; haematocrit values; white blood cell count;
red blood cell count; haemoglobin concentration; percentages of lymphocytes,
heterophils, monocytes, basophils, and eosinophils; and weights of heart,
liver, gizzard, adrenals, and pancreas. Haemoglobin values in the exposed
birds were slightly lower than in the control birds, but the difference was
not significant. The authors concluded that the exposure conditions do not
24
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
prevent normal development of the quail embryo.
In a series of experiments using chick and turkey embryos Hills et al
(1974) exposed the embryos to low density (0.2 mW/cm2 and 0.005 mW/cnr)
microwave radiation at 6 GHz. They also exposed embryos to high density
(1.02 W/cm2, 0.246 W/cm2, 0.l23W /cm2 and 0.051 W/cm2) microwave
radiation at 2450 MHz for 45 to 300 seconds. It was concluded that the low
density exposures did not significantly affect hatching weights or
hatchability. In the high density irradiation experiments, the embryos
exposed on day zero of incubation showed no difference in hatchability.
Those exposed to 0.246 W/cm2 or 1.02 W/cm2 on day tw - of incubation failed
to hatch. In general the high density exposures resulted in lower hatching
weight and reduced hatchability when compared to the controls. The
authors suggest that the observed effects are nonthermal in nature, having
been caused by pearl chain formation of particles within the eggs. There is
no indication in the paper that the temperature of the eggs was monitored,
or that the controls were m aintained at a temperature equal to that
attained by the exposed eggs. Therefore, it is impossible to know whether
or not the same effects would have been observed in the controls under
sim ilar thermal conditions.
Braithwaite et al (1991b) described and evaluated a technique for
exposing chicken eggs to 2.45 GHz radiation at 3.6 mW/cm2 during
incubation. The eggs were exposed from day 0 to days 7, 14, and 19 of
25
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
incubation and compared to control eggs conventionally incubated. No
significant difference in percent fertility or hatchability was found between
treatm ents. Eggs exposed to microwave radiation for 19 days appeared to
have a lower, though non-significant, hatchability. The authors suggest this
is due to a temperature drop which occurred late in the experim ent, and is
probably not a microwave effect.
The results of the studies reviewed above are sometimes conflicting.
It would be necessary to perform more research under carefully controlled
conditions to ensure the microwave exposed and sham-exposed anim als are
experiencing identical thermal environments before definite conclusions can
be drawn about the athermal effects of microwave radiation. Unfortunately,
it is difficult to match the heating patterns of microwave radiation with
conventional heating methods.
Effects on testes
There is a concern that exposure to microwave radiation may have a
detrimental effect on semen quality, given the proximity of the testes to the
body surface in most mammals, and the necessity to m aintain the testes at
a specific temperature to produce healthy sperm.
Chowdhurry and Steinberger (1970) conducted an experim ent to
determine the effects of exposure to heat on the germinal epithelium of rat
testes. The scrotums of anaesthetized rats were exposed to 43°C for 15
26
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
minutes. The authors state that the primary spermatocytes are susceptible
to heat damage at various stage of development, but the degenerative
changes may not appear until they have attained a later step in their
development.
Lebovitz and Johnson (1987) exposed unrestrained male rats to 1.3
GHz radiation for 8 hours at a specific absorption rate of 9mW/g, which the
authors claim is at or above the lethal level for chronic exposure in the rat.
The rats were then sacrificed at either 6.5, 13, 26 or 52 days after exposure.
This was done to measure the effects of the radiation after 0.5, 1, 2, and 4
cycles of the sem iniferous epithelium or one full spermatogenic cycle. The
body mass; total testis mass; mass of right tunic, left epididymis, and
sem inal vesical; daily sperm production; and levels of circulating follicle
stim ulating hormone and luteinizing hormone were measured. No
significant treatm ent effects were found in any of these parameters. The
authors conclude that the testes will remain below the critical threshold for
damage if all physiologic and behavioral mechanisms for thermoregulation
remain intact. No indication is given that the temperature of the testes was
monitored during exposure.
Cleary et al (1989) exposed mouse spermatozoa to 27 MHz and 2450
MHz radiation in v itro for one hour. The authors found a significant
reduction of in v itro fertilization of mouse ova when the specific absorption
rate was 50 W/kg or greater.
27
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
In a study published in 1948, Imig et al found that exposure to 12 cm
[2.498 GHz] radiation for 10 minutes caused testicular degeneration in
Sprague-Dawley rats, if the temperature of the testes rose to 35°C or higher.
This was below the temperature necessary for infra-red radiation to cause
damage. The authors caution that the method employed to measure the
temperature of the testes may not have been accurate. This seems likely
since the area of the testes showing the most damage was the side located
closest to the radiation source, while the temperature probe was located
further back in a relatively shielded portion of the testes.
It appears that even when damage is done to the sperm the effects
are reversible. Fahim et al (1975) and Berman et al (1980) found that
exposure to 2,450 MHz radiation caused temporary infertility in male rats
for 10 months and 4 weeks respectively. It is possible that the damage is
caused by excess heat, and the effects are not seen in subsequent
generations of sperm as spermatogenesis continues.
28
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
MATERIALS AND METHODS
29
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
When applied to biological subjects, microwave radiation is usually
contained in either a multi-mode cavity or an anechoic chamber.
An anechoic chamber is an enclosure constructed of highly absorbent
m aterial to prevent reflection of microwave radiation back to the subject.
This allows precise measurements of the microwave energy to which the
subject is exposed. Anechoic chambers are able to provide large uniform
fields (Michaelson and Lin, 1987). Unfortunately, anechoic chambers are
expensive to design and build, and provide uneven heating to large objects
because the power comes from only one direction (Tranquilla, 1994).
A multi-mode cavity is usually a shielded metal box similar to a
domestic microwave oven (Michaelson and Lin, 1987). It is designed to
reflect microwave radiation in many different patterns throughout the
cavity. It is easy to design and build, and provides fairly uniform heating
by distributing power in as many different patterns as possible, to irradiate
the object from all sides. The disadvantage of a multi-mode cavity is the
difficulty of determining the radiation dose absorbed by the subject, because
the act of measuring the power level at any one point in the cavity changes
the mode pattern, and therefore the distribution of power (Tranquilla,
1994).
Cage design
In this experiment the cage was a specially constructed multi-mode
30
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
cavity (School of Engineering, University of Guelph), built on an angle iron
skeleton. The walls and ceiling were made of 22-gauge perforated metal,
w ith 0.32 cm perforations 0.96 cm apart. The floor was a commercially
available plastic flooring for pigs (Filter Eeze, BCM Manufacturing Ltd.).
The floor was assumed to be transparent to microwaves. The floor was
suspended above a 22-gauge sheet m etal sub-floor. The sub-floor was
slanted from front to back, and sides to centre, to funnel waste material to a
drainage door at the back of the cage.
The dimensions of the cage were 153 cm wide x 367 cm long x 150 cm
high. The cage was divided in two by a 22-gauge sheet metal partition,
extending from the ceiling to the sub-floor, and wall to wall. One side of the
cage was used to house microwave exposed pigs, and the other side was
used to house the control pigs. Each side was 2.8305 m2, or 0.47 m2 per pig.
The recommended area is 0.26 m2 per pig for pigs 20 kg or less, and 0.48 m2
per pig for pigs less than 50 kg (Agriculture and Agri-Food Canada, 1993).
The largest pig housed in this cage was 37.2 kg, so the stocking density was
w ell w ithin recommended lim its (Plate 1).
All joints were sealed with braided metal wire or aluminum duct tape
to prevent microwave leakage. The cage was checked for leaks with a
Simpson Microwave Leakage Tester (Simpson Electric Company, Elgin,
Illinois) at the beginning of every exposure period, and every third day
during the exposure. Only two leaks were discovered during exposure and
31
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
they were repaired immediately. No microwave radiation was ever
discovered leaking into the control side of the cage.
Microwave generator design
Microwave power was produced by a Panasonic 2M210-M1 magnetron
from a domestic microwave oven, generating 2450 MHz radiation. This
magnetron had a life expectancy of 500 hours. Therefore, it needed to be
replaced during the first replicate. It was replaced with a commercial
quality Hitachi 2M120 magnetron, which proved to be much more durable.
The second magnetron was replaced with an identical model in the sixth
replicate, after it was damaged during a lightning storm.
Microwave power was delivered to the cage through a WR284
waveguide to a three-way circulator (Merrimac, W est Caldwell, New Jersey)
with an attached dummy load (Royal Microwave Services). It then passed
through a Gerling Moore (Palo Alto, California) H-plane 90° elbow to a
Gerling Moore WR284 - WR430 transition waveguide. This larger
waveguide extended into the cage.
Inside the cage, the wave guide had a series of thirteen holes to
release the energy to the cavity. Each hole measured 6 mm wide x 60 mm
long with the long dimension parallel to the length of the waveguide. The
holes were 50 mm apart (end to end) and alternately set 15 mm off centre of
the waveguide (Plate 2).
32
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Power density measurements
The microwave power inside the cage was measured using styrofoam
cups filled with 100 ml of water (Plate 3). The temperature of the water
w as measured, then the power was turned on for 120 seconds and a second
temperature measurement was taken. The power density to which each
water sample was exposed was determined by the following formula:
P = (C*4186*M*T/t*A)*lOOO
(Tranquilla, 1994)
where:
P is the power level (mW/cm2),
C is the specific heat capacity of water (1 kcal/kg*°C),
4186 is a constant to convert kcal to joules,
M is the mass of the water irradiated (kg),
T is the temperature change (°C),
t is the length of tim e of exposure (seconds),
A is the surface area of the water being exposed (cm2),
1000 converts watts to m illiwatts.
Before starting each replicate, power density measurements were
made at each of nine positions in the cage. The results of this procedure
indicated that the average power density in the cage was (mean ± S.D.) 17.9
± 7.9 mW/cm2. This is w ithin the "high power density" range (greater than
33
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
10 mW/cm2) as established by the 1973 Warsaw International Symposium
on biological effects and health hazards of microwave radiation (from WHO,
1981). There did not appear to be any areas within the cage that had a
consistently higher or lower power density than others. This experiment
was intended to be a comparison study with a sim ilar experiment conducted
at the University of Prince Edward Island. In that experiment the power
density used was in the 10 - 20 mW/cm2 range, with a radiation frequency
of 915 MHz.
This experiment involved the use of animals which were free to
interact with each other, and move about within the exposure chamber.
Therefore, the surroundings of each animal were often changing with
respect to reflected power and standing waves. Also the animals were
exposed during a period of their lives when they were growing rapidly.
Their surface area:body mass ratio was changing considerably, so the
amount of energy absorbed per unit mass was also changing during the
experiment. Due to these complications, it was decided that only the
incident power density would be measured, since the specific absorption rate
would be constantly changing throughout the exposure period, as the pigs
changed position in the cage and grew.
Supplemental heat for the control pigs
Pigs in the control side were warmed by two, 250 w att infra-red heat
34
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Lamps, suspended 91 cm from the floor. The temperature at floor level
directly below the heat lamps was 3l°C. The temperature cooled with
distance from the lamps to room temperature (14-16 °C) at the walls and
com ers of the cage. The power density of the infra-red radiation was 17.66
mW/cm2.
The environmental chamber
The experiment was performed in an environmental chamber at the
Arkell Swine Research Station. The room temperature was maintained at
16-17 °C for the first replicate. The temperature for the remaining
replicates was 14-16 °C. The room was lighted 24 hours per day to allow
constant observation by video cameras. Day length and light level do not
appear to have any effect on pig performance or their pattern of food
consumption (Braude and Mitchell, 1958). Hacker et al (1974) found that
gilts kept under 12:12 hour light: dark cycles reached first estrous sooner
than gilts kept under continuous complete darkness. Perera and Hacker
(1984) found that 24 hour lighting increases the length of estrous in gilts.
However, since both the control and treated groups were exposed to 24 hour
light, the method of lighting used in this experiment should not have had
any effects which would confound the findings of this experiment.
35
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Experiment design
E xperim ent 1;
The first experiment was a Random Complete Block Design, blocked
on time. Each block contained two experimental units. One experimental
unit was exposed to microwave radiation as a supplemental heat source
(MW group). The other experimental unit was warmed with infra-red
radiation (Control group). Each experimental unit contained six randomly
assigned pigs. The values collected for measurements on each pig were
averaged to give an experimental unit value. This allowed for the removal
of one or more pigs from the study, without causing an unbalanced design.
There were a total of five blocks (n=5). Each block contained 12
female pigs. A total of sixty recently weaned pigs were used in this
experiment. The average age of the pigs at the tim e of their entry into the
experiment was 31.4 days ± 4.88 days (mean ± S.D.). The average weight
was 7.97 kg ± 1.78 kg (mean ± S.D.). The pigs were supplied by the Arkell
Swine Research Unit.
Statistical analysis
The statistical analysis was performed using the general linear model
procedure (GLM) analysis of variance for repeated measures in the SAS
software (SAS, version 6.09, 1988). The means and standard error of the
means are reported. The significance level for all results in these
36
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
experiments was p=0.05. The covariate used in the model was the initial
w eight of each experimental unit. The model used was as follows:
Y-. = p + t; + r,- + ft (Xij - x)+ Eiik
where:
Y = the response variable,
p = overall mean,
t = treatm ent effect (a fixed effect); (i-1,2),
r = block effect (j=l,...,5),
Pi is the regression of y on x for the i’th treatment,
Xjj = covariate value of experimental unit ij,
x = overall mean of covariate values,
E ;jk
= experimental errors.
Assumptions:
eijk is independent and normally distributed with a mean of 0 and a
common variance a2,
The covariate is unaffected by the treatm ents or blocks,
The covariates are measured without errors,
Each regression of y on x is linear.
Experiment 2:
The second experim ent was a Completely Random Design. In this
experim ent weight gain, blood chemistry, and sem en quality at maturity of
37
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
male weaner pigs were analyzed. Twelve pigs were randomly assigned to
either the microwave radiation chamber (n=6) or the infra-red chamber
(n=6). Each pig was considered an experimental unit. The average age of
the pigs was 27.3+2.0 days (mean ± S.D.), and the average weight was
7.20±1.2 kg (mean ± S.D.).
There was difficulty obtaining intact male weaner pigs for this
project. When a large number of males became available at one time, it was
decided that they would be used in a completely random design experiment.
The shortage of male pigs made it necessary to consider each pig an
experimental unit, instead of a group of six pigs constituting an
experimental unit as was done in the first experiment. W ith the facilities
available, data for feed consumption, feed:gain ratio and behaviour could
not be collected for individual anim als. Therefore, those parameters could
not be analyzed statistically, but the data are presented for the sake of
comparison with the female pigs. No statistical inferences should be drawn
from the data on feed consumption, feed: gain ratio and behaviour.
The exposure conditions for this experiment were the same as for the
first experiment.
Statistical analysis
The statistical analysis was performed using the general linear model
procedure in the SAS software (SAS, 1988). Initial weight of each pig was
38
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
used as the covariate. The following model was used:
¥« = M-+ t; + p; (Xy - x)+ eijk
where:
Y = the response variable,
]lx
= overall mean,
t = treatm ent effect (a fixed effect); (i=l,2),
P; is the regression of y on x for the fth treatment,
Xjj = covariate value of experimental unit ijf,
x = overall mean of covariate values,
Sjjk= experimental errors.
Assumptions:
sijk is independent and normally distributed with a mean of 0 and a
common variance ct2,
The covariate is unaffected by the treatm ents,
The covariates are measured without errors,
Each regression of y on x is linear.
Care and sampling practices
The pigs were placed in the cages one day before treatm ent began to
give them a chance to become accustomed to their surroundings. The day
the heat sources were turned on was considered day 0. They were warmed
by their respective heat sources for twenty-eight days. Then, they were
39
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
removed from the cages and mixed w ith the general population of the barn.
A detailed description of the animal handling techniques and sam pling
methods follows.
Feed
The pigs were fed a starter feed for the duration of the exposure
period. When they were moved to the growing wing of the bam , they were
switched to a grower feed, then eventually to a sow or boar feed.
W hile in the cage, feed consumption of the pigs was calculated by
backweighing the feed on days 7, 14, 21, and 28. Very little feed appeared
to be spilled. Occasionally, the pigs would urinate in a feeder. When this
happened, the spoiled feed was cleaned out, and the feeder was moved to a
different com er of the cage. This seem ed to prevent a recurrence of the
problem. In the microwave side of the cage, the feeders were grounded by a
metal bar joining the feeder to the w all of the cage. This prevented the
possibility of the microwave radiation inducing a current in the m etallic
feeders and shocking the pigs.
Blond Samples
A 10 ml blood sample was taken from each pig on days 0, 7, 14, 21,
and 28 of treatm ent. Then, blood sam ples were taken every 28 days until
the gilts were bred or the first sem en sam ple was taken from the boars.
40
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Blood samples were obtained from the sub-orbital sinus using a 16-gauge
needle, and collected in a 10 ml heparinized Vacutainer (Becton-Dickinson).
Blood samples were centrifuged and 2 x 1.5 ml aliquots of plasma were
pipetted off and frozen at -10 °C, for analysis of blood chemistry and
progesterone content.
Blood chem istry was analyzed at the diagnostic laboratory of the
Atlantic Veterinary College, University of Prince Edward Island.
Progesterone levels were determined by radio-immuno assay in the
endocrinology laboratory of the Atlantic Veterinary College, using a
technique developed by Dr. L.A. Bate (Bate, 1996).
W eighing
The pigs were weighed on the same days as blood samples were
taken. In addition, the pigs were weighed every second week after being
removed from the cage, until they were bred or a semen sample collected.
Videotapes
The pigs were videotaped 24 hours per day for 28 days in the first
replicate. In subsequent replicates the pigs were videotaped 24 hours per
day for the first three days, then eveiy fourth day, until the end of the
experimental period (ie. days 0, 1, 2, 6, 10, 14, 18, 22, and 26). A
Panasonic A G -60l0s tim e-lapse video tape recorder was used. Panasonic
41
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
WV-CD110A colour cameras with Cosmicar 8.5 mm 1:1.5 lenses were
mounted outside the cage. The outside walls of the cage were spray painted
with a matte black paint to reduce glare, so the cameras could record
activity inside the cage. A Panasonic WV-CM110A monitor with a built in
timer/switcher was used to switch images sent to the VTR between the
Control side and the Microwave side of the cage, at approximately thirty
second intervals.
The videotapes were used to measure the percent of tim e
the pigs spent performing several selected behaviours. The tim es were
averaged to give the amount of tim e spent per pig in performing each
behaviour. A software package called Observer, version 3.0 from the Noldus
Company (The Netherlands) was used to facilitate data collection from the
videotapes.
The observed behaviours and their working definitions were the
following:
1. lying alone - pig lying ventrally or laterally with less than one half of its
body length in contact with another pig;
2. lying in a huddle - pig lying ventrally or laterally with more than one
half of its body length in contact with another pig;
3. at feeder - pig standing or sitting with snout in the opening of feeder;
4. standing - sitting, standing, playing, rooting, fighting, and other
activities;
5. drinking - snout on water nipple;
42
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
6. fighting - shoulder to shoulder contact, pushing, slashing with teeth,
biting the shoulders and ears of the other pig.
Sampling interval
In order to save tim e while observing the videotapes, an efficient
sampling interval (i.e. the greatest length of time at which an observation of
the pigs' behaviour could be recorded without losing accuracy) was
determined for recording the first four behaviours listed above. Three tapes
were chosen at random and behaviours were recorded by instantaneous
sampling at one minute intervals in an observational data file. The data
files were used to calculate a tim e budget per pig. Then, with the help of
Margaret Quinton (1996), a SAS program was written which would
determine a tim e budget per pig using observations at two, five, ten, twelve,
fifteen, seventeen, and twenty minute intervals from these data files. A
general linear model analysis was performed to contrast the resulting time
budgets, with the tim e budget for one minute intervals. No significant
differences were found for the contrasts of one minute sampling interval
versus any of the other sam pling intervals. The sampling intervals of
twelve m inutes and greater tended to indicate that rare behaviours, such as
lying alone during the first week, did not occur. In fact, the frequency of
this behaviour was so low as to be non-significantly different from zero. It
was thought that, even w ith such infrequent occurrence, this behaviour
43
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
should not be lost in the gaps of the sampling intervals; therefore, it was
decided that a ten minute sam pling interval would be used. An
instantaneous sampling method was used to record the number of pigs
performing each behaviour at each ten minute mark.
The number of observations of fighting were grouped to give the
m inutes spent fighting per pig per day and the length of each fight. A
continuous sampling method was used to record all occurrences of fighting
and drinking.
Cleaning
The cage was cleaned daily by opening the sub-floor access doors,
inserting a hose, and washing out waste materials. Cleaning usually t^ok
15-20 minutes, during which tim e the microwave was turned off. An
attempt was made not to splash water up through the floor to the pig area.
However, both controls and microwave pigs occasionally got wet.
Growing
After being removed from the cage, the pigs were moved to the
growing wing of the swine bam . There, controls and microwave pigs from
the same block were housed together. They were moved to the breeding
wing when they reached the 90-120 kg range, and were then able to see
other pigs and occasionally mix with pigs of the opposite sex.
44
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Breeding
The fem ales were bred and the date recorded when the first estrus
was detected.
A sem en sample was collected from the m ales when they were about
seven to eight months old. Three samples were collected from each male,
and checked for volume, concentration, sperm viability, and sperm motility.
Concentration, viability, and m otility were determined by a method
provided by Dr. M. Buhr (Buhr, 1995). The values for each pig were
averaged. One male from the microwave exposed group would not mount
an estrus female or the dummy, so a semen sample could not be collected
from him.
The concentration of the sem en was checked by diluting 5 pi of semen
in 5 ml of 2.9% sodium citrate solution, then measuring the percent
absorbance of 550 nm light with a spectrophotometer (Spectronic 20, Bausch
& Lomb). The measurements on the spectrophotometer were converted to
number of sperm x 106/ ml using a calibration chart.
The viability of the sperm was measured by mixing 50 pi of eosinnigrosin stain with 5 pi of semen for one minute. The mixture was then
smeared on a slide and let dry overnight. Then the slides were examined
under a microscope and the number of dead and live sperm at the time of
staining were counted. Dead sperm absorbed the stain and therefore,
appeared pink; live sperm were clear.
45
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Mobility was measured by mixing 25 pi of 0.85% NaCl with 1 pi of
sem en on a microscope slide. The number of progressively motile,
nonprogressively motile and nonmotile sperm were counted and the
percentage of each was calculated.
Farrowing
The gilts were followed through to their first farrowing. The number
of pigs bom per litter, the weight of the pigs at one day old, and the number
of pigs of each sex were recorded and analyzed. In addition, any pigs that
died within the first two days of birth were sent to post-mortem for an
autopsy unless the cause of death was obvious (e.g., crushed, fell out of
farrowing pen).
46
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
RESULTS
47
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Experiment 1: Females
Growth and feed data
There was no significant difference between treatm ents for the
weights of the animals (Figure 3), or the weight gain (Figure 7) during the
exposure period. There was also no significant difference in the weights of
the pigs from the tim e they were removed from the exposure chamber until
day 140 of the experiment (Figure 6). No significant difference between
treatm ents was detected for the feed consumed during the exposure period
(Figure 4), nor was a difference detected for the feedrgain ratios of the
animals (Figure 5).
Out of 30 gilts in each treatm ent, 7 infra-red exposed pigs and 8
microwave exposed pigs died or were euthanized before farrowing. There
was no significant difference in the number of gilts which survived to
farrow.
A visual inspection of the pigs did not reveal any differences in hair
growth.
Blood data
No significant differences were detected between treatm ent groups for
the albumin (Figure 8), calcium (Figure 9), chloride (Figure 10), globulin
(Figure 11), glucose (Figure 12), potassium (Figure 13), progesterone (Figure
14), sodium (Figure 15), total protein (Figure 16) levels, albumin:globulin
48
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
ratio (Figure 17), or sodiumrpotassium ratio (Figure 18), in the blood, either
during the exposure period or until day 140 of the experiment.
Reproduction data
No significant difference was detected between treatm ent groups for
the age or weight of the gilts at the tim e of first estrus (Table 4).
Three infra-red exposed gilts, and 2 microwave exposed gilts required
a second breeding. There was no significant difference between treatm ents
for the number of gilts that required a second breeding. One microwave
exposed and 2 infra-red exposed gilts never showed signs of estrus. They
were euthanized and the reproductive tract examined for signs of
abnormalities. The infra-red exposed gilt had cycled but her heat was
m issed. One microwave exposed gilt appeared to have been in estrus the
day she was euthanized, but gave no behavioural signs. The other
microwave-exposed gilt showed no signs of cycling, but no abnormalities
were discovered.
No significant differences were found in the average number of
piglets bom per litter, or the average weight of the newborn piglets, or the
number of pigs that survived to two days of age (Table 5).
None of the piglets had a cause of death attributable to microwave
exposure of the dam.
49
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Behaviour data
There was a significant difference between treatm ents for the percent
of time the pigs spent lying alone (p=0.0250) (Figure 19). As the
experiment progressed, the microwave exposed pigs spent more tim e lying
alone than did the infra-red exposed pigs. There was also a significant
difference between treatm ents for the percent of time spent lying in a
huddle (p=0.0418) (Figure 20), and the percent of time the pigs spent
standing , walking around, playing, rooting or engaging in other activities
during the exposure period (p=0.0428) (Figure 23). The pigs exposed to
microwaves showed an overall reduction in time spent in a huddle, while
infra-red exposed pigs slightly increased their time spent in a huddle. In all
three cases the differences between the treatm ents were quadratic. No
differences due to treatments were found for the percent of time the pigs
spent with their heads in the feeders (Figure 22), or for the total tim e the
pigs spent lying (Figure 21).
A comparison of the mean number of drinks per pig per day showed
no significant differences due to treatm ent (Figure 24). The number of
m inutes spent fighting per pig per day showed a significant quadratic
treatm ent effect (p=0.0379) (Figure 25). There was also a significant
quadratic effect in the number of fighting bouts a pig was involved in each
day (p=0.0415) (Figure 26). The infra-red exposed pigs were involved in
more fights, and the fights lasted longer than those of the microwave
50
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
exposed pigs.
Experiment 2: males
Growth and feed data
No significant differences between treatments were found with
respect to the weight (Figure 3) or weight gain (Figure 7) during the
exposure period. There was a significant quadratic difference detected in
the weights of the m ales from the time they were removed from the
microwave cage until day 140 (p=0.0l45) (Figure 7). The infra-red exposed
pigs were slightly heavier than the microwave exposed pigs until day 140,
when the microwave exposed pigs became heavier.
A visual inspection of the pigs did not reveal any differences in hair
growth.
All pigs survived to the end of the experiment.
The feed consumption (Figure 4) and feedrgain ratio (Figure 5) data
for the m ales is presented for the sake of comparison with the levels found
for the fem ales. As stated above, no statistical analysis was performed on
this portion of experim ent 2 and no statistical inferences should be drawn
from these data.
Blood data
No significant treatm ent effects were found regarding the albumin
51
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
(Figure 8), calcium (Figure 9), chloride (Figure 10), globulin (Figure 11),
glucose (Figure 12), potassium (Figure 13), progesterone (Figure 14), sodium
(Figure 15), total protein (Figure 16) levels, or sodium:potassium ratio
(Figure 18) of the blood. There was a linear treatm ent effect in the
album in :globulin ratio (p=0.0363) (Figure 17). The microwave exposed pigs
had a lower albuminiglobulin ratio than the infra-red exposed pigs.
Reproduction data
No significant treatm ent effects were detected in the volume, or
concentration of the semen collected. There were also no treatm ent effects
on the percent of sperm showing progressive mobility, non-progressive
mobility, or immobility. Percent viability showed no treatm ent effects.
(Table 6).
Behaviour data
The tim e budget of the m ales (Figures 19-23) as well as the amount
of time spent fighting (Figure 25), length of fights (Figure 26), and number
of drinks per day (Figure 24) is presented for the sake of comparison with
the fem ales. As stated above, no statistical analysis was performed on this
portion of experiment 2, and no statistical inferences should be drawn from
these data. Information for day 1 is m issing for the drinking and fighting
behaviours and for day 10 of the drinking behaviour, because the recording
52
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
heads of the VCR were deteriorating. The video picture quality became too
poor for use.
53
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
DISCUSSION AND CONCLUSIONS
54
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
These experiments were carried out to investigate the possible use of
2,450 MHz microwave radiation as a safe source of supplemental heat for
weaner pigs. Growth, feed consumption and conversion, blood chemistry,
behaviour and reproductive ability were analyzed, and most parameters
showed no significant differences between the two treatment groups. This
was expected, but the parameters measured were chosen for the reasons
described below.
Growth rates, and feed consumption and conversion were measured
because previous experimenters found treatm ent effects related to those
parameters when animals were exposed to microwave radiation. Lu et al
(1987), and Pazderova-Vejlupkova & Josifko (1970) found decreased body
m ass in rats exposed to microwave radiation. Morrison et al (1987a) found
a significant difference in feed:gain ratios between microwave and infra-red
exposed chicks. There was some concern that the microwave exposed pigs
in these experiments m ight be too hot or too cold, which would cause an
alteration in these parameters.
Albumin, globulin, calcium, and total protein were measured because
McRee et al (1980) found significant differences in levels of those
parameters between microwave and sham-exposed rabbits. Changes in
albumin levels can indicate dehydration or kidney problems. Changes in
globulin levels may indicate liver problems or serum loss due to bum s.
Altered calcium levels may indicate an absorption problem. Changes in
55
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
total protein levels ran indicate dehydration, blood loss or liver problems.
Yerushalmi et al (1984 ) found elevated glucose levels in microwaveexposed rabbits. This could be caused by stress or excitement.
Chloride, sodium, and potassium , were also measured because they
can serve as indicators of possible health problems. Appropriate chloride,
potassium, and sodium levels are necessary for the proper functioning of
nerves and muscles, and for m aintaining cell integrity. Changes in sodium,
potassium, and chloride levels could indicate problems with the kidneys or
gastro-intestinal tract.
Progesterone levels were m easured to determine whether the
microwave radiation altered the onset of first estrus. Microwave radiation
and light are both forms of electromagnetic energy. Light schedules have
been shown to alter the age of first estrus (Hacker, 1974), and the length of
estrus (Perera and Hacker, 1984). The corpus luteum produces elevated
progesterone levels after ovulation, so progesterone levels were measured to
determine whether estrus occurred. None of the gilts showed an increase in
progesterone levels without also going into heat.
Some parameters differed significantly, and those differences w ill be
discussed below.
Experiment 1
Three of the four parameters which make up the time budget of the
56
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
pigs showed significant differences due to treatment. These behaviours
were mutually exclusive, so a treatm ent effect in one would be expected to
alter the levels measured in one or more of the others. The primary concern
in measuring the percent of tim e the pigs spent lying alone or in a huddle,
at the feeder, or standing was to try to infer whether the pigs were being
maintained at a comfortable body temperature.
Pigs can respond to thermal stress through both physiological and
behavioural means. In a cold environment, the pig may respond
physiologically by reducing the blood flow to the skin, piloerection,
shivering, or increasing metabolic rate. Behaviourally, the pig may alter its
posture to reduce body contact with the floor thereby reducing conductive
heat loss, or huddling with other pigs to reduce radiant and convective heat
loss. (Curtis, 1983).
The animals exposed to microwave radiation in this experiment
showed no physiological effects such as increased hair growth, increased
feed consumption or decreased weight gain when compared to the infra-red
exposed pigs. This agrees with the findings of Chou et al (1992), who found
no significant differences in growth, food and water consumption, or blood
chemistry (including those blood parameters examined in this study), for
rats exposed to low level microwave radiation for 25 months.
The pigs did, however, alter their time spent lying alone, huddled,
and standing, but not the toted tim e spent lying.
57
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
As the exposure period progressed the microwave exposed pigs spent
more time lying alone than the infra-red exposed pigs, and reduced their
tim e spent lying in a huddle. It is possible that the microwave exposed pigs
were therm ally more comfortable than the infra-red exposed pigs.
Subjective observations of the videotaped behaviours indicated that the
infra-red exposed pigs huddled tightly under the heat lamps while
microwave exposed pigs formed a looser huddle, and did not return to the
huddle as quickly if one rolled away. Thus, the microwave exposed pigs
appeared to be more comfortable, thermally. Unfortunately, poor picture
quality made it impossible to quantify the "tightness" of the huddle with
consistency.
The infra-red exposed pigs also reduced the percent of tim e they
spent standing, in comparison with, the microwave exposed pigs. For the
first three days of the exposure period, the infra-red exposed pigs spent
more time standing than the microwave exposed pigs, but from day 6 to day
26 the profiles of tim e spent standing is nearly identical for the two
treatm ent groups. This relative difference in tim e spent standing
corresponds with the levels of fighting which were observed in the
treatm ent groups. The infra-red exposed pigs were comparatively more
active and engaged in more agonistic interactions, than did the microwave
exposed pigs.
The profiles of tim e spent fighting and number of fighting bouts per
58
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
pig was significantly different for the two treatments. The infra-red exposed
pigs spent much more tim e fighting, and were involved in fights much more
often than the microwave exposed pigs during the first three days of the
exposure period. The profile of fighting behaviour in the infra-red exposed
pigs resembles that seen typically in groups of recently mixed pigs. Newly
regrouped pigs may spend 17% of their first 90 minutes together fighting,
but that is reduced to 0.2% to 2% in a stable group (McGlone and Curtis,
1985).
One explanation for the differences in fighting is the possibility that
the microwave exposed pigs were attem pting to cope with heat stress by
rem aining inactive. This would agree with de Lorge (1984), who found that
increased colonic tem peratures of rhesus monkeys exposed to microwave
radiation impaired observing-response rates of the monkeys. D’Andrea et al
(1979) also found decreased activity levels of rats exposed to microwaves,
and suggested that therm al loading may be responsible. If the pigs were
heat stressed, however, they gave no other indication of it, such as playing
with the waterer, or rolling in manure to try to w et their bodies.
Another possible explanation is that the microwave exposed pigs
experienced an increased level of serotonin in the brain. This may be
caused by a direct effect of the microwaves on the brain, or perhaps an
increase in the rate of tryptophan uptake from the diet. Mench et al (1995),
mention several examples of increased serotonin levels causing a reduction
59
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
of aggression in birds and mammals. Further investigation of serotonin
levels in the pigs would be needed to strengthen or reject this hypothesis.
Experiment 2
In the experiment conducted with male pigs, only the grower weights
(weight from day of removal from the exposure chamber to day 140 of the
experiment), and the albumin:globulin ratio showed significant differences.
The grower weights differed slightly but significantly with the
microwave exposed pigs weighing less until the last measurement of the
experiment. It is not known why the effect was seen only after the pigs
were removed from the exposure chamber. The fact that it did not occur to
the female pigs seems to indicate that the effect was not related to
microwave exposure.
The albumimglobulin ratio of the microwave exposed pigs was
significantly lower than in the infra-red exposed pigs. The albumin levels
in the microwave exposed pigs also showed a nonsignificant trend of being
lower than in the infra-red exposed pigs. These findings agree with the
results of a study by McRee et al (1980), who found significantly reduced
albumimtotal globulin ratios and albumin levels in rabbits exposed to
microwaves. Reduced albumin levels and albumin:globulin ratios may
indicate loss of albumin through the kidneys or gastrointestinal tract. If the
overall health of the anim als had been affected, these changes may have
60
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
indicated a location of the problem. The anim als appeared healthy in all
other respects though, so it was felt that the reduced albuminrglobulin ratio
was possibly due to a Type I error. That is, a significant difference was
indicated when one did not really exist.
61
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
SUMMARY
62
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
The results from these experiments presented several significant
treatm ent effects. However, none of the effects seem to be detrimental to
the health and well-being of the pigs. No pigs died or appeared to have
suffered due to causes attributable to microwave radiation exposure.
It could be argued that the behavioural effects were beneficial to the
pigs. If fighting could be reduced in newly-mixed pigs it would decrease the
likelihood of bruising, skin damage, and infections from cuts.
Microwave radiation has been used safely to incubate eggs (Kondra et
al,1970; Kondra et al,l972), rewarm hypothermic mice (Gordon, 1982),
piglets ( Bate et al, 1992), lambs (Braithwaite et al, 1990), and warm chicks
(Morrison et al, 1987a), and pigs (Morrison et al, 1989; Morrison et al,
1987b). At appropriate power levels, it is a safe source of supplemental
heat for weaner pigs.
In addition, air quality in pig barns could be improved by the use of
microwave radiation. Since the pigs would be less dependant on warm air
to reduce heat loss, ventilation rates could be increased to reduce the levels
of airborne contaminants.
If microwave radiation is to be used as a supplemental heat source in
a farm environment^ it is important to keep certain precautions in mind.
One would not place a living animal in a conventional oven to provide it
with warmth. Likewise, one should not expose an animal to microwave
radiation without knowledge of the power ievels being supplied. It is not
63
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
difficult to measure the power levels, but it does require vigilance to ensure
they remain at safe and comfortable levels. Used properly, microwaves can
provide safe and effective supplem ental heat for young pigs.
64
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
PLATES
65
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
P late 1:
E quipm ent used to expose pigs to infra-red or microwave radiation. The
cage is divided in half w ith th e n ear side supplying infra-red rad iatio n and
th e far side supplying microwave radiation. All eq u ip m en t was located in
a n environm ental cham ber.
66
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
P late 2:
M icrowave generator, waveguide, and dum m y load used to supply
m icrow ave rad ia tio n to th e pigs during th e experim ent.
67
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission
P la te 3:
Equipm ent used to m easure power d ensity of the microwave rad iatio n in
the cage.
68
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
TABLES
69
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Table 1:
Some frequencies set aside for Industrial, Scientific, and Medical uses.
From WHO, 1981; and Repacholi, 1983.
I.S.M. Frequencies
6.78 MHz ± 1.5 kHz
13.56 MHz ± 6.78 kHz
27.12 MHz ± 160 kHz
40.68 MHz ± 20 kHz
433.92 MHz ± 15 kHz
915 MHz ± 2 5 kHz
2.45 GHz ± 50 kHz
5.80 GHz + 75 kHz
22.125 GHz ± 125 kHz
70
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Table 2:
Sources of Background Radiation, and their respective power levels on
Earth. (From Repacholi, 1983).
Source
Power level
Below 300 GHz
Below 30 GHz
Quiet sun
2xlO'7pW/cm2
Sun spots
lO^jiW/cm2
Earth
0.3pW/cm2
Human body
0.3pW/cm2
3xl0^jaW/cm2
71
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Table 3:
The penetration depth (cm) of several frequencies of electromagnetic
radiation in biological tissues with high and low water contents. From
Department of National Health and Welfare Canada, 1977.
Frequency (MHz)
100
300
915
2450
3000
Low water content
tissue,
e.g. fat, bone
60.4cm
32.1
17.7
11.2
9.7
High water content
tissue, e.g. muscle,
skin
6.67
3.9
3.0
1.7
1.6
72
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Table 4:
Mean (± S.E.M.1) age and weight of the pigs in experiment 1 at first estrus.
Infra-red
Microwave
S.E.M.
Age (days)
188.0
185.1
3.41
Weight (kg)
116.24
116.42
2.64
1 Standard error of the mean.
73
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Table 5:
Mean (± S.E.M.1) number of piglets per litter, average w eight of piglets, and
percent male for the first litter bom from animals in experiment 1.
Infra-red
Microwave
S.E.M.
# pigs
8.05
8.32
0.85
Average weight
1.36
1.39
0.07
Percent male
53.56
46.66
6.29
1Standard error of the mean.
74
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Table 6:
Mean (± S.E.M.1) volume (ml), concentration (106 sperm/ml), progressive
mobility (%), nonprogressive mobility (°/o), immobility (%), and viability (%)
of the sem en collected from experiment 2.
Microwave
S.E.M.
Infra-red
S.E.M.
Volume (ml)
193,05
35.14
170.37
38.50
Concentration
(l0 6spenn/ml)
392.65
83.87
539.63
91.87
Progressive
mobility (%)
64.37
9.73
60.45
10.66
Nonprogressive
mobility (%)
12.43
7.75
28.46
8.49
Immobility (%)
23.62
4.11
11.09
4.5
Viability (%)
79.33
3.17
74.47
3.47
1Standard error of the mean.
75
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
FIGURES
76
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 1:
Schematic diagram of the electromagnetic spectrum, (from Ford, 1968).
/
Photon
x
Frequency Wavelength
(sec-1)
(cm)
•24X1017
3X10-M-3 X 1 0 -“
Cosmic
ray
Dhotons
£4X101*5
3X10-1S--
*4X 10“
3X 10-is--
£4 XIP9-?
3X10-“ --
-W a v e le n g t h - s iz e of elem en tary particle
3 X 1 0 -“
- L im it of nuclear gam m a rays
4X107.S
• L im it o f accelerator en ergy
3 X 1 0 -1 °
Gamma rays
53X10-? ::
X rays
- L im it of 3tom ic X rays
Ultraviolet
-
S3X10-3,<
4 X 1 0 -3
4X10-5
4 X 1 0 -7
4 X 1 0 -0
3X 10-*
4X 10-11
3 X 106
^Visible light
Infrared
Microwaves
Radar
UHF
VHF, FM
Shortwave
AM radio
Longwave
radio
3 X 10*
4 X 1 0 -1 ®
* W a v elen g th " r a d iu s o f earth
■f '- r il * r.* -^
77
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 2:
Schematic diagram illustrating wavelength, and the electric and magnetic
vectors of electromagnetic radiation. (From Health and Welfare Canada,
1978).
Y
VELOCITY
Z
78
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 3:
Comparison, of mean body weights (kg) of pigs during exposure to
microwave radiation (2.45GHz, 17.9mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs and experiment 2 involved males.
in fra-red fe m a le s
m ic ro w a v e fe m a le s
O)
O.
18-
<S
a
1 16®
3
m i4 _
01
g
ai
5
12-
10 -
w eek
24
infra-red m a le s
22-
m ic ro w a v e m a le s
cs
CL
1 8 -
(D
Q.
I<D 16_
3
®
14O
gI
o
5 1210 -
79
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 4:
Comparison, of mean weight gain (kg) of pigs during exposure to microwave
radiation (2.45GHz, 17.9mW/cm*) or infra-red radiation. Experiment 1
involved female pigs and experim ent 2 involved m ales.
in fra -red fe m a le s
4.5-
m ic ro w a v e fe m a ie s
o»
4-
O
in fra -re d m a le s
4.5m ic ro w a v e m a le s
4-
3-
1.5w eek
80
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 5:
Comparison of m ean feed consumption (kg) of pigs during exposure to
microwave radiation (2.45GHz, lT.SmW/cm2) or infra-red radiation.
Experiment 1 involved fem ale pigs. The data for experiment 2 with male
pigs are presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
in fra -re d fe m a le s
6-
feed
consumed
per pig
(kg)
m ic ro w a v e fe m a le s
w eek
in fra -red m a le s
8-
7-
feed
consumed
per pig
(Kg)
m ic ro w a v e m ale s
4-
w eek
81
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 6:
C om parison of m ean feedrgain ratio of pigs during exposure to microwave
rad iatio n (2.45GHz, lT.JtaiW/cni2) or infra-red radiation. E xperim ent 1
involved fem ale pigs. The d ata for experim ent 2 w ith m ale pigs are
p resen ted for th e sake of com parison. No statistical analysis h as been
perform ed on th is portion of experim ent 2.
infra-red fe m a le s
2 .5 -
m icro w av e fe m a le s
u>
G>
Q. 1 . 5 -
O)
0 .5 -
week
infra-red m a le s
-x -
2.5-
m icro w av e m ale s
o>
CL
a 1.5-
c
flj
cn
*®
0
o 11
-
0 .5 -
week
82
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 7:
Comparison of mean body weights (kg) of pigs, which had been exposed to
microwave radiation (2.45GHz, lT.Sm^tytm2) or infra-red radiation for
twenty-eight days, from the end of exposure period until day 140 of the
experiment. Experiment 1 involved female pigs, and experiment 2 involved
males.
120
110 -
infra-red fe m a le s
100 -
m ic ro w a v e fe m a le s
90™
Oi
SO'
£
05
'3
70-
5
60-
5040-
112
126
day
120
110J
In fra -red m a le s
100 -
m ic ro w a v e m a le s
9080-
£
70-
50-
40-
56
112
84
126
day
83
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 8:
Comparison of mean album in levels {g/\) of pigs, which had been exposed to
microwave radiation (2.45GHz, 17.9mW/cm^ or infra-red radiation for
twenty-eight days, from the beginning of the exposure period until day 140
of the experiment. Experiment 1 involved female pigs, and experiment 2
involved males.
40
38-
in fra -red fe m a le s
36-
m ic ro w a v e fe m a le s
5
O) 3 4 3230-
2624-
22
14
20
w eek
40
e
3
38-
in fra -red m a le s
36-
m ic ro w a v e m a le s
34-
at
1
32-
|
30-
I
28*
2624-
22
20
w eek
84
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 9:
Comparison of mean calcium levels (mmol/1) of pigs, which, bad been
exposed to microwave radiation (2.45GHz, 17.9m.Wcm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment. Experiment 1 involved female pigs, and
experiment 2 involved males.
3 .2
in fra -red fe m a le s
2.8-
m ic ro w a v e fe m a le s
2.2
1 .8 1 .6 -
14
w eek
3.2
in fra -re d m a le s
2 .8-
|
m ic ro w a v e m a le s
2 .6 -
£
S
2 .4 i(
o>
-:
-2 2 .2 E
Io
21.8 1 .6 1 .4
w eek
85
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 10:
Comparison of mean chloride levels (mmol/1) of pigs, which had been
exposed to microwave radiation (2.45GiIz, 17.9mW/cnr) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment. Experiment 1 involved female pigs, and
experiment 2 involved males.
115
in fra -red fe m ales
110 O
£
m ic ro w a v e fe m a le s
i
£ 105'
j2
©
>
.2
■§ 100O
.c
20
w eek
in fra-red m a le s
110 -
m ic ro w a v e m a le s
o
£
1 0 5 -'
Vi
<
0
>
o
2 iooo
95-
w eek
86
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 11:
Comparison of mean globulin levels (gfl) of pigs, which had been exposed to
microwave radiation (2.45GHz, lT.SmV^cm2) or infra-red radiation for
twenty-eight days, from the beginning of the exposure period until day 140
of the experiment. Experiment 1 involved female pigs, and experiment 2
involved males.
in fra -re d fe m a le s
35-
m ic ro w a v e fe m a le s
03
r 30<
s
>
Q
C
20-
14
w eek
40
in fra -re d m a le s
35m ic ro w a v e m ale s
o
»
<a
30-
o>
c
E
o
a
25-
20-
w eek
87
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 12:
Comparison of mean glucose levels (mmol/1) of pigs, which had been exposed
to microwave radiation (2.45GHz, lT.OmW/cm2) or infra-red radiation for
twenty-eight days, from the beginning of the exposure period until day 140
of the experiment. Experiment 1 involved female pigs, and experiment 2
involved males.
10
9-
in fra -re d fe m a le s
m ic ro w a v e fe m a le s
o
E
7-
E
a
<0
>
aa,>
o
u
3
O)
54-
21-
w eek
in fra-red m ales
m ic ro w a v e m a le s
o
7-
£
E
12
w eek
88
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 13:
Comparison of mean potassium levels (mmol/l) of pigs, which had been
exposed to microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment Experiment 1 involved female pigs, and
experiment 2 involved males.
in fra -red fe m a le s
6 .5 -
m ic ro w a v e fe m a le s
_£
5 .5 -
4 .5 -
4-
3 .5 -
14
w eek
in fra -red m a le s
6 .5 -
m ic ro w a v e m a le s
6£
5 .5 -
4 .5
4-
3 .5 -
20
w eek
89
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 14:
Comparison of mean progesterone levels (ng/ml) of pigs, which had been
exposed to microwave radiation (2.45GHz, lT.SmW/cm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment. Experiment 1 involved female pigs, and
experiment 2 involved males.
0 .9 '
in fra -red fe m a le s
0 .8m ic ro w a v e fe m a le s
«
0.60 .5 -
<5
0 .4 -
?
w.
0.
0 .3 -
0 .2 0 . 1-
14
w eek
“
0 .9 '
in fra-red m ales
0.8-
m ic ro w a v e m a le s
0. 6 0 .5 -
CL
0.20 .1-
20
w eek
90
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 15:
Comparison of mean sodium levels (mmol/l) of pigs, which had been exposed
to microwave radiation (2.45GHz, n.SmW /cm2) or infra-red radiation for
twenty-eight days, from the beginning of the exposure period until day 140
of the experiment. Experiment 1 involved female pigs, and experiment 2
involved males.
150
148140
m ic ro w a v e fe m a le s
5 144o
E
£ 142n
? 140-
0
1 138i
1 136134132130“
0
i—
2
r
------ 1
----- 1
----- 1--- 1
-- 1----- 1---- ■
— r—
4
6
8
10
12
14
16
l
-----18
20
week
150
148-
in fra -re d m a le s
Sodium
levels
(m m o l/I)
146-
m ic ro w a v e m a le s
144142140-
136134-1
132130
14
20
w eek
91
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 16:
Comparison of mean total protein levels (g/1) of pigs, which had been
exposed to microwave radiation (2.45GHz, iT.SmW/cm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment. Experiment 1 involved female pigs, and
experiment 2 involved males.
75-
in fra -re d fe m a le s
70-
O)
m ic ro w a v e fe m a le s
65-
55;
5045403530
w eek
75-
in fra -re d m ales
70-
I
o
>
at
m ic ro w a v e m a le s
6 5 '
60“
c
©
55-
‘
CL
50-
o
|
45*
o
403530
10
w eek
92
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 17:
Comparison of mean albuminiglobulin ratios of pigs, which had been
exposed to microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment. Experiment 1 involved female pigs, and
experiment 2 involved males.
1 .8 -
in fra -re d fe m a le s
1 .6-
m ic ro w a v e fe m a le s
o
c
3
o
o>
n.
0 .4 -
0 .2 -
w eek
in fra -re d m a le s
1.6 -
M
ZJ
m ic ro w a v e m a le s
1 .2 -
i
1-
|
0 .8 -
i 0.60 .4 -
0 .2 14
week
93
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 18:
Comparison, of mean sodium:potassium ratios of pigs, which had been
exposed to microwave radiation (2.45GHz, l7.9mW/cnr) or infra-red
radiation for twenty-eight days, from the beginning of the exposure period
until day 140 of the experiment. Experiment 1 involved female pigs, and
experiment 2 involved males.
40
infra-red fe m a le s
38-
36-
m icrow ave fe m a le s
30-
28
o
2624-
2220
14
20
w eek
40
infra-red m a le s
38-
36-
m icrow ave m a le s
3432-
3
30-
24-
2220
w eek
94
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 19:
Comparison of mean percent of time spent lying alone during exposure to
microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 with male
pigs are presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
100
90-
in fra -re d fe m a le s
80o)
m ic ro w a v e fe m a le s
7060-
40-
20-
10-
day
100
90in fra -re d m a le s
®
0
80-
01
70-
m ic ro w a v e m a le s
as
£
>.
“
ca)
60-
a.
o>
o 503E3 4 0 o
c
30d
ow)
<
D
a. 20-
10-
day
95
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 20:
Comparison of mean percent of time spent lying in a huddle during
exposure to microwave radiation (2.45GHz, lT.OmW/cm2) or infra-red
radiation. Experiment 1 involved female pigs. The data for experiment 2
with male pigs are presented for the sake of comparison. No statistical
analysis has been performed on this portion of experiment 2.
100
90-
in fra-red fe m a le s
80-
£
03
70-
£
6CH
1
CL
tfj
®
■X3
50-
m ic ro w a v e fe m a le s
4030-
c
©
o
20 -
op
a
IQ -
24
day
100
©
TJ
90-
in fra-red m ales
80-
m ic ro w a v e m a le 3
JC
£ 70U)
£
60-
IQ.
50-
o
30-
_>
■
«
| 40-
e
<D
S
oa
20-
IQ14
day
96
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 21:
Comparison of mean percent of total time spent lying during exposure to
microwave radiation (2.45GHz, lT.&mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 with male
pigs are presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
100
O
)
c
90-
in fra -red fe m a le s
80-
n .c r o w a v e fe m a le s
>.
70-
c
<s
GO­
Q_
«
©
E
'S
c
40-
©
o
I.
2010-
20
day
100
90-
in fra -re d m a le s
80-
m ic r o w a v e m a le s
f .
7 0 -
C
g.
0)
60i
E
50-
o
o
cID
U
aa.>
403 0 -
2010 -
14
26
day
97
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 22:
Comparison of mean percent of time spent with head in feeder during
exposure to microwave radiation (2.45GRz, 17.9mW/cm2) or infra-red
radiation- Experiment 1 involved female pigs. The data for experiment 2
with male pigs are presented for the sake of comparison. No statistical
analysis has been performed on this portion of experiment 2.
infra-red fe m a le s
m ic ro w a v e fe m a le s
10
12
14
16
18
20
22
24
26
day
100
9 0-
in fra-red m a ie s
8 0 -
c
<0
m ic ro w a v e m a le s
6 0-
a.
a>
O
£
■s
5 0-
4 0 -
c
©
ow
<
D
a.
30-
20 ;
10 -
10
12
14
16
18
20
22
24
26
day
98
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 23:
Comparison of mean percent of time spent standing during exposure to
microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 with male
pigs are presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
in fra -re d fe m a ie s
m ic ro w a v e fe m a le s
24
26
100
903,
in fra -re d m a le s
80-
m ic ro w a v e m a le s
|
a)
c
<
D
CL
60-
a
50-
2
40-
E
c<o
u
10 ”
24
day
99
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 24:
Comparison of mean number of drinks per pig during exposure to
microwave radiation (2.45GHz, l7.9mW/cm2) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 with male
pigs are presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
45-
in fra -rad fe m a le s
40-
m ic ro w a v e fe m a le s
o. 3 5 30-
■6 25&
20 -
3
15-
105-
14
26
day
45-
in fra -re d m a le s
40-
m ic ro w a v e m a le s
cn
a. 3 5 -
3025-
20 3
15-
10 5-
24
day
100
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 25:
Comparison of mean number of minutes spent fighting during exposure to
microwave radiation (2.45GHz, 17.9mW/cmi) or infra-red radiation.
Experiment 1 involved female pigs. The data for experiment 2 with male
pigs are presented for the sake of comparison. No statistical analysis has
been performed on this portion of experiment 2.
in fra -re d fe m a fe s
7-
m ic ro w a v e fe m a le s
a.
a
day
in fra -re d m a le s
m ic ro w a v e m a le s
<9
Q.
05
C
'2 3
C
©
CL
OS
at
3
3C
E
24
day
101
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Figure 26:
Comparison of mean number of fighting bouts during exposure to microwave
radiation (2.45GHz, iT.OmW/cm2) or infra-red radiation. Experiment 1
involved female pigs. The data for experiment 2 with male pigs are
presented for the sake of comparison. No statistical analysis has been
performed on this portion of experiment 2.
in fra -re d fe m a le s
m ic ro w a v e fe m a le s
aa
4-
a
o
no
£
3
C
14
24
day
in fra -red m a le s
m ic ro w a v e m a le s
®
Q.
O)
a.
<o
a.
9)
o
no
E
3C
24
day
102
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
BIBLIOGRAPHY
103
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Agriculture and Agri-Food Canada, 1993. R ecom m en ded Code o f P ractice for
th e C are an d H an dlin g o f Farm A n im als. Agriculture and Agri-food
Canada, Ottawa, Ontario.
Barber, E.M., H.L. Classen, P.A. Thacker, 1989. Energy use in the
production and housing of poultry and swine - An Overview.
C anadian Journal o f A n im al Science. 69:7-21.
Bate, L.A., J.G. Crossley, R. Wade, 1992. Effective rewarming of
hypothermic piglets using 915-MHz microwaves. C anadian Journal
o f A n im al Science. 72:161-164.
Bate, L.A., 1996. Professor of endocrinology and behaviour, University of
Prince Edward Island. Personal communication.
Berman, E., J.B. Kinn, H.B. Carter, 1978. Observations of mouse fetuses
after irradiation with 2.45 GHz microwaves. H ealth Physics, 35:791801.
Berman, E., H.B. Carter, D. House, 1980. Tests of mutagenesis and
reproduction in male rats exposed to 2450 MHz (CW) microwaves.
B ioelectrom agnetics, 1:65-76.
Berman, E., H.B. Carter, D. House, 1981. Observations of rat fetuses after
irradiation with 2450-MHz (CW) microwaves. Jou rn al o f M icrow ave
Pow er, 16:9-13.
Berman, E., H.B. Carter, D. House, 1982a. Reduced weight in mice offspring
after In Utero exposure to 2450-MHz (CW) microwaves.
B ioelectrom agnetics. 3:285-291.
Berman, E., H.B. Carter, D. House, 1982b. Observations of Syrian hamster
fetuses after exposure to 2450-MHz microwaves. Journal o f
M icrow ave Pow er, 17:107-112.
Braithwaite, L.A., W.D. Morrison, J.H. Smith, L. Otten, D.C.T. Pei, 1990.
Utilisation of microwave (MW) radiation for warming hypothermic
lambs. C anadian Jou rn al o f A n im a l Science, 70:1169.
Braithwaite, L.A., W.D. Morrison, L. Bate, L. Otten, B. Hunter, D.C.T. Pei,
1991a. Effect of exposure to operant-controlled microwaves on certain
blood and immunological parameters in the young chick. P o u ltry
Science, 70:509-514.
104
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Braithwaite, L.A., W.D. Morrison, L. Otten, D. Pei, 1991b. Exposure of
fertile chicken eggs to microwave radiation (2.45 GHz, CW) during
incubation: technique and evaluation. Journal o f M icrow ave P o w er
and E lectrom agnetic E nergy. 26:206-214.
Braithwaite, L.A., W.D. Morrison, L. Otten, L.A. Bate, 1993. Microwave
radiation as a heat source for young livestock. L ive sto ck E n viro n m en t
IV. Eds. E.Collins, C.Boon. Publication 3-93 St. Joseph, Mi.: ASAE.
Braude, R.,and K.G. Mitchell, 1958. The effect of light on fattening pigs.
Proceedings o f th e N u tritio n Society, l7:xxxviii.
Budd, R.A.,and P. Czerski, 1985. Modulation of mammalian immunity by
electromagnetic radiation. Jou rn al o f M icrow ave Pow er. 20:217-231.
Buhr, M. 1995. Professor of reproductive physiology, University of Guelph.
Personal communication.
Bundy, D.S.,and T.E. Hazen, 1975. Dust levels in swine confinement
systems associated with different feeding methods. T ran saction s o f
th e A m erican S ociety o f A g ricu ltu ra l E ngineers. 18:137-139,144.
Chemovetz, M.E., D.R. Justesen, N.W. King, J.E. Wagner, 1975. Teratology,
survival, and reversal learning after fetal irradiation of mice by 2450MHz microwave energy. Jou rn al o f M icrow ave P ow er, 10:391-409.
Chou, C.-K., A.W. Guy, L.L. Kunz, R.B. Johnson, J.J. Crowley, J.H. Krupp,
1992. Long-term low-level microwave irradiation of rats.
B ioelectrom agnetics, 13:469-496.
Chowdhurry, A.K.,and E. Steinberger, 1970. Early changes in the germinal
epithelium of rat testes following exposure to heat. Journal o f
R eprodu ctive F ertility, 22:205-212.
Cleary, S.P., L.M. Liu, R. Graham, J. East, 1989. In vitro fertilization of
mouse ova by spermatozoa exposed isothermally to radio-frequency
radiation. B ioelectrom agnetics. 10:361-369.
Curtis, S.E., 1983. E n viro n m en ta l M a n a g em en t in A n im a l A griculture. The
Iowa State University Press, Ames.
Czerska, E.M., E.C. Elson, C.C. Davis, M.L. Swicord, P. Czerski, 1992.
Effects of continuous and pulsed radiation on spontaneous
105
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
lymphoblastoid transformation of human lymphocytes In Vitro.
B ioelectrom agnetics. 13:247-259.
D'Andrea, J.A., O.P. Gandhi, J.L. Lords, C.H. Durney, C.C. Johnson, L.
Astle, 1979. Physiological and behavioral effects of chronic exposure
to 2450-MHz microwaves. Jou rn al o f M icrow ave Power. 14:351-362.
Davidson, J.A., P.A. Kondra, M.A.K. Hamid, 1976. Effects of microwave
radiation on eggs, embryos, and chickens. Canadian Journal of
Animal Science, 56:709-713.
deLorge, J.O., 1984. Operant behavior and colonic temperature of M acaca
m u la tta exposed to radio frequency fields at and above resonant
frequencies. B ioelectrom agnetics. 5:233-246.
Department of National Health and Weuare, 1977-78. H ealth A sp ects o f
R adio F requency and M icrow ave R adiation E xposure , P a rts 1 an d 2.
Department of National Health and Welfare, Brooke Claxton
Building, Ottawa, Ontario, Canada.
DeWitt, J.R., J.A. D'Andrea, R.Y. Emmerson, O.P. Gandhi, 1987. Behavioral
effects of chronic exposure to 0.5mW/cm2 of 2,450-MHz microwaves.
B ioelectrom agnetics. 8:149-157.
Dumey, C.H., C.C. Johnson, P.W. Barber, H. Massoudi, M.F. Iskander, J.L.
Lords, D.K. Ryser, S.J. Allen, J.C. Mitchell, 1978. R adiofrequency
R adiation D o sim etry H andbook, second edition, USAF School of
Aerospace Medicine, Brooks Air Force Base, Texas.
Fahim, M.S., Z. Fahim, R. Der, D.G. Hall, J. Harman, 1975. Heat in male
contraception (hot water 60°C, infrared, microwave, and ultrasound).
C ontraception. 11:549-562.
Ford, K.W., 1968. B asic P hysics. Gin and Company, Waltham,
Massachusetts, Toronto, London.
Gordon, C.J., 1982. Rewarming mice from hypothermia by exposure to 2450
MHz microwave radiation. Cryobiology. 19:428-434.
Hacker, R.R., G.J. King, W.H. Bearss, 1974. Effects of complete darkness on
growth and reproduction in gilts. Journal o f A nim al Science. 39:155.
106
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Hamrick, P.E.,and D.I. McRee, 1975. Exposure of the Japanese quail
embryo to 2.45 GHz microwave radiation during the second day of
development. Journal o f M icrow ave Pow er. 10:211-221.
Heller, J.H.,and A.A. Teixeira-Pinto, 1959. A new physical method of
creating chromosomal aberrations. N a tu re. 183:905-906.
Hills, G.A., P.A. Kondra, M.A.K. Hamid, 1974. Effects of microwave
radiations on hatchability and growth in chickens and turkeys.
C anadian Journal o f A n im al Science. 54:573-578.
Imig, C.J., J.D. Thomson, H.M. Hines, 1948. Testicular degeneration as a
result of microwave irradiation. P roceedings o f the S o c ie ty for
E xperim en tal B iology a n d M edicine. 69:382-386.
Jauchem, J., 1993. Alleged health effects of electric or magnetic fields:
additional misconceptions in the literature. Journal o f M icrow ave
P ow er an d E lectrom agnetic E nergy. 28:140-155.
Johnson, C.C., and A.W. Guy, 1972. Nonionizing electromagnetic wave
effects in biological materials a^d systems. P roceedings o f th e IEEE.
60:692-718.
Johnson, R.B., D. Spackman, J. Crowley, D. Thompson, C.K. Chou, L.L.
Kunz, A.W. Guy, 1983. Effects of long-term low-level radiofrequency
radiation exposure on rats: open-field behavior and corticosterone.
U SAFS AM-TR-83-42.
Kondra, P.A., W.K. Smith, G.C. Hodgson, D.B. Bragg, J. Gavora, M. A.
Hamid, R.J. Boulanger, 1970. Growth and reproduction of chickens
subjected to microwave radiation. C anadian Journal o f A n im al
Science. 50:639-644.
Kondra, P.A., M.A. Hamid, G.C. Hodgson, 1972. Effects of microwave
radiation on growth and reproduction of two stocks of chickens.
C anadian Journal o f A n im a l Science. 52:317-320.
Lebovitz, R.M.,and L. Johnson, 1987. Acute, whole - body microwave
exposure and testicular function of rats. B ioelectrom agnetics. 8:3743.
Lu, S.T., N. Lebda, S.M. Michaelson, S. Pettit, D. Rivera, 1977. Thermal
and endocrinological effects of protracted irradiation of rats by 2450MHz microwaves. R adio Science. 12:147-156.
107
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Lu, S.T., N.A. Lebda, S.J. Lu, S. Pettit, S.M. Michaeison, 1987. Effects of
microwaves on three different strains of rats. R adiation Research.
110:173-191.
McGlone, J.J.,and S.E. Curtis, 1985. Behavior and performance of weanling
pigs in pens equipped with hide areas. Journal o f A nim al Science.
60:20-24.
McRee, D.I., R. Faith, E.E. McConnel, A.W. Guy, 1980, Long-term 2450MHz CW microwave irradiation of rabbits: evaluation of
hematological and immunological effects. Journal o f M icrow ave
Power. 15:45-52.
Mench, J.A.,and M.M. Shea-Moore, 1995. Moods, minds and molecules: the
neurochemistry of social behavior. A p p lied A n im al B ehaviour
Science. 44:99-118.
Michaeison, S.M., 1970. Biological effects of microwave exposure. In
B iological E ffects a n d H ea lth Im plication s o f M icrow ave Radiation:
Sym posium Proceedings. Cleary, S.F., ed., U.S. Public Health Service
Publication BRH/DBE70-2.
Michaeison, S.M.,and J.C. Lin, 1987. Biological E ffects and H ealth
Im plications o f R adiofrequ en cy R adiation. Plenum Press, New York,
New York.
Morrison, W.D., I. McMillan, L.A. Bate, L. Otten, 1986. Behavioural
observations and operant procedures using microwaves as a heat
source for young chicks. P o u ltr y Science. 65:1516-1521.
Morrison, W.D., E. Amyot, I. McMillan, L. Otten, D.C.T. Pei, 1987a.
Performance of male broiler chicks exposed to heat from infrared or
microwave sources. P o u ltry Science. 66:1762-1765.
Morrison, W.D., E. Amyot, I. McMillan, L. Otten, D.C.T. Pei, 1987b. Effect
of duration of reward upon operant heat demand of piglets receiving
microwave or infrared heat. C anadian Journal o f A nim al Science.
67:903-907.
Morrison, W.D., K.L. LaForest, I. McMillan, L. Otten, D.C.T. Pei, 1989.
Growth and reproductive performance of gilts raised under
supplementary infrared or microwave heat. Canadian Journal o f
A n im al Science. 69:27-31.
108
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
NCRP, 1986. Biological E ffects a n d E xposure C riteria for R adiofrequ en cy
E lectrom agnetic F ields. NCP report no. 86. National Council on
Radiation Protection and Measurements. Bethesda, Maryland.
Pazderova-Vejlupkova, J., M. Josifko, 1979. Changes in the blood count of
growing rats irradiated with a microwave pulse field. A rch ives of
E nviron m ental H ealth . 34:44-50.
Perara, A.N.M.,and R.R. Hacker, 1984. The effects of different photoperiods
on reproduction in the sow. Journal o f A n im al Science. 58:1418-1422.
Quinton, M., 1996. Computer services group, Department of Animal and
Poultry Science, University of Guelph. Personal communication.
Repacholi, M.H., 1983. R adiofrequ en cy a n d M icrow ave Energy.
Roberti, B., G.H. Heebels, J.C.M. Hendricx, A.H.A.M. de Greef, O.L.
Woithuis, 1975. Preliminary investigations of the effects of low-level
microwave radiation on spontaneous motor activity in rats. Biologic
effects o f n on ion izin g radiation . Annals of the New York academy of
sciences, v.247.
SAS Institute Inc. 1988. Cary, North Carolina.
Saffer, J.D.,and L.A. Profenno, 1992. Microwave - specific heating affects
gene expression. B ioelectrom agn etics. 13:75-78.
Schwan, H.P., 1970. Interaction of microwave and radio frequency radiation
with biological systems. In Biological E ffects a n d H ealth Im plication s
o f M icrow ave R adiation : S ym posiu m Proceedings. C leary , S.F., ed.,
U.S. Public H ealth S e rvic e P ublication BRH /DBE70-2.
Shandala, M.G., M.I. Rudnev, M.A. Navakatian, A.N. Marzeev, 1977.
Patterns of change in behavioural reactions to low power densities of
microwaves. In te rn a tio n a l S ym posiu m on th e B iological E ffects o f
E lectrom agnetic W aves. Air lie, Virginia.
Stuchly, M.A., 1983. Fundamentals of the interactions of radiofrequency and
ir icrowave energies with matter. B iological E ffects and D o sim e try o f
N onion izing R a d ia tio n Grandolfo,M., S.M.Michaelson, and A.Rindi,
eds., Plenum Press, New York & London.
Tranquilla, J.M., 1994. Professor of electrical engineering, University of
New Brunswick. Personal communication.
109
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Tyler, P.E., ed., 1975. Biologic E ffects o f N onion izing R adiation. Annals of
the New York Academy of Sciences.
USAF School of Aeronautical Medicine, 1985. Effects of long-term, low-level
radiofrequency radiation exposure on rats. USAF School of
Aeronautical Medicine, 9:1-20. USAFSAM-TR-85-64.
World Administrative Radio Conference, 1979. Geneva, Switzerland.
World Health Organization, 1981. E n viron m en tal H ealth C riteria 16:
R adiofrequ en cy and M icrow aves, Geneva.
Yerushami, A., I. Katzap, F. Gottesfeld, D.D. Bass, 1984. Systemic
alteration in blood glucose levels following localized deep microwave
hyperthermia. Journal o f M icrow ave Power. 19:73-76.
110
Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
Документ
Категория
Без категории
Просмотров
0
Размер файла
3 927 Кб
Теги
sdewsdweddes
1/--страниц
Пожаловаться на содержимое документа