lauren@vortex.UUCP (Lauren Weinstein) (08/17/84)
a212 1114 16 Aug 84
AM-Microwaves-Cancer, Bjt,730
Study Finds Microwave Exposure Linked With Higher Rates of Cancer
By BARTON REPPERT
Associated Press Writer
WASHINGTON (AP) - Glandular changes and a higher rate of cancer were
found among laboratory rats chronically exposed to low-intensity
microwaves, according to a study by University of Washington
researchers.
Results emerging from the $4.5 million study sponsored by the Air
Force, have prompted substantial concern among researchers
investigating the biological and health effects of non-ionizing
radiation, according to Microwave News, a specialized scientific
newsletter.
''In addition to a general increase in cancer incidence, the
experimental results suggest that microwave exposure is responsible
for wide-ranging effects related to the adrenal glands and the entire
endocrine system,'' the publication reported.
The adrenal glands, adjacent to the kidneys, and other glands of the
endocrine system produce chemical hormones vital to the regulation of
many bodily functions.
The Microwave News account noted that the findings could provide an
experimental basis for widely reported complaints of headaches,
dizziness, memory loss and fatigue from workers chronically exposed to
microwave radiation
Microwave radiation is emitted by a wide variety of sources
including thousands of military and civilian radar installations,
satellite ground stations, relay towers for long-distance telephone
links, television transmitters, as well as microwave ovens and
citizens band radios.
Environmental Protection Agency surveys have found that 99.4 percent
of the people in 15 major cities were exposed to microwave and
radiofrequency radiation at power levels of 1 microwatt per square
centimeter or less.
Government microwave-oven regulations mandate that at the time of
sale, radiation emitted from the devices must not exceed 1,000
microwatts per square centimeter, measured at a distance 5 centimeters
from the oven's outside surface. For older ovens, the limit rises to
a maximum of 5,000 microwatts per square centimeter.
Although the University of Washington study utilized the same
frequency used in many microwave ovens, the experiment also exposed
the rats to special pulsing and modulation characteristics that are
not found in the consumer cooking devices.
If confirmed by other researchers, the test results ''would
undermine the 1982 American National Standards Institute
radiofrequency and microwave radiation exposure standard,'' according
to Microwave News. This voluntary standard sets safety levels of
1,000 to 5,000 microwatts per square centimeter for human exposure to
microwave radiation.
The research team, headed by Professor Arthur W. Guy at the
university's School of Medicine in Seattle, exposed rats up to 25
months to pulsed microwaves at a level of 480 microwatts per square
centimeter.
The EPA has prepared draft ''guidance'' for establishing a legally
enforceable safety standard for exposure to mirowave and
radiofrequency radiation.
But the document's release - originally set for June - has been
delayed, reportedly due to an internal dispute within the agency. EPA
Assistant Administrator Joseph Cannon has said the agency is
considering a number of options, including abandonment of the draft
standard.
Results of the University of Washington study were presented at a
scientific conference last month in Atlanta.
The researchers disclosed that there were 16 malignant tumors among
100 exposed rats, compared to four tumors among 100 control animals.
The 16 tumors in exposed rats included seven involving the endocrine
system - two thyroid, two pituitary and three adrenal gland tumors.
The average weight of the adrenal glands in the exposed animals was
double that of the control animals, the researchers said.
In addition, there were six benign adrenal tumors - known as
pheochromocytomas - in the exposed rats, but none among the controls.
This type of tumor has been associated with high blood pressure,
headaches and stress in human patients.
Dr. Samuel Milham, an epidemiologist for the Washington State Health
Department, said results of the study appeared to point to a ''stress
reaction'' in the exposed animals.
''It looks like the microwave radiation may have been a tumor
promoter,'' he said in a telephone interview. ''It didn't initiate the
cancers, but once some cancer cells got going it promoted growth of
the tumors.''
Milham has conducted statistical reviews that found increased rates
of leukemia among power-station operators, aluminum workers, power
and telephone linemen as well as other workers chronically exposed to
electric and magnetic fields.
''The scientific data suggest the need for further epidemiological
studies involving workers exposed to microwave and radiofrequency
radiation,'' said David LeGrande, director of occupational safety and
health for the Communications Workers of America. ''Many thousands of
workers may be exposed to hazardous levels, and they need to know
what the dangers associated with such exposure might be.''dmmartindale@watcgl.UUCP (Dave Martindale) (08/19/84)
It sounds like the article in question is reporting on a test using microwaves, and then speculating about the effect of other electromagnetic radiation on people. Does anyone know for sure? I wouldn't be surprised to find that microwaves and 60Hz electric fields have entirely different effects on the body. And since when do televison transmitters and CB radios give off microwaves? I'm very interested in what the researchers may have found, but the article is fuzzy enough that I'm not sure exactly what they did find.
lauren@vortex.UUCP (Lauren Weinstein) (08/20/84)
I wouldn't expect to find much technical detail in a wireservice story--but you can attempt to obtain the actual report if you're interested in the details. By the way, UHF television transmitters operate at frequencies high enough that we'd expect to see much the same effects as for higher frequency microwaves. An interesting problem now being studied is the effect of high frequency RF (even at low power) when in close proximity to the body. This includes devices such as 450 Mhz hand-held radios and the newer cellular hand-helds, which operate at almost twice that frequency. --Lauren--
rbg@cbosgd.UUCP (Richard Goldschmidt) (08/20/84)
>It sounds like the article in question is reporting on a test using >microwaves, and then speculating about the effect of other electromagnetic >radiation on people. Does anyone know for sure? I wouldn't be surprised >to find that microwaves and 60Hz electric fields have entirely different >effects on the body. >Dave Martindale My guess is that the original article referenced other research papers, like studies which demonstrate the health hazards of extermely low frequency radiation (ELF - intended to be used in conjunction with a very large antenna for submarine communications), and studies which demonstrate an increase in birth defects in women who sleep under electric blankets during their pregnancies. There is a lot of research out there, it isn't just speculation. The fact that is was lifted from the AP news wire is reason enough not to expect scientifically accurate reporting. Rich Goldschmidt {ucbvax|ihnp4|decvax|allegra}!cbosgd!rbg There is no avant garde. There are only people who are a little late.
smb@ulysses.UUCP (Steven Bellovin) (08/22/84)
I checked the "Science News" article on the microwave study. The original study was in the Aug. 17 issue of "Microwave News", for anyone who wants to go to the original source. The most important datum presented is that the rats were exposed to pulsed 2450 Mhz radiation for 21 hours a day. The Air Force, which funded the study, was primarily interested in the effects of radar frequencies; the Science News article states, without elaboration, that "using rats, the wave- length must be shorter". The power density was chosen to "approximate a rate of energy that is equal to or lower than the current voluntary U.S. safety standard for humans of 0.4 watts per kilogram of body tissue. The study found immune system abnormalities, plus strong efects on the endocrine system. The cancer rate is described statistically significant, with only 1% probability that this was a chance result. However, the tumor rate among the exposed rats -- 16 cases, vs. 4 for the control rats -- was lower than normal for that strain of rats. The team that did the study cautions that the results must be replicated before being considered reliable, especially in the area of tumor formation. That latter should involve about 10,000 rats, not just 100, they say. No mention at all was made of lower frequencies.