computed electric and magnetic fields of nearby high-voltage power lines. We found a statistically
significant correlation between both fields and the occurrence of suicide, but we could not determine
whether more or less than the expected number of suicides occurred at locations of high field strengths
(14). Since the total power-frequency field at any site is due to contributions from many sources- high-
voltage lines, low-voltage lines, household wiring and appliances- we then proceeded with a study of
measured field strengths. The mean measured magnetic field strength for the suicide group (867
µgauss), was found to be significantly higher than that of the control group (709 µgauss) (2). The
proportion of suicide addresses in the high-field-strength region was 40% greater than the proportion of
control addresses (Table 10.6).
Table 10.6. PROPORTIONS OF SUICIDE AND CONTROL ADDRESSES FOUND IN REGIONS OF
VERY HIGH (1 500 µgauss) AND HIGH (1000 µgauss) MEASURED POWER-FREQUENCY
MAGNETIC FIELD STRENGTH
Wertheimer and Leeper studied the association between childhood cancer (in Denver,
Colorado), and living in proximity to power lines. Homes were classified on the basis of their distance
to high-current (high magnetic field) and low-current (low magnetic field) line configurations. It was
found that the death rate from leukemia, Iymphomas and nervous system tumors was about twice the
expected rate in high-current homes (15). In a related study (16), which was different in several
important respects (17), Fulton et al. failed to find an association between electrical wiring
configuration and childhood leukemia in Rhode Island.
In a study involving children exposed to environmental high-frequency EMFs, differences were
found in various cardiovascular indices between 100 children (aged 5-14) who lived in areas where the
EMF ranged up to 30 v/m, and 70 control children who experienced fields of less than 0.l v/m (18). The
exposed group had faster pulse and respiratory rates, increased blood pressure, and exhibited a slower
recovery from a stress test.
These studies, and one other that failed to find an association between living near power lines
and visits to a physician (19), are, so far as we have been able to determine, the only epidemiological
studies that involve exposure to environmental EMFs.
Occupational exposure.
There have been many surveys and studies of the side-effects of EMF
exposure in the workplace. At high frequencies, the workers studied have included radar, radio, and TV
technicians, and the operators of various specialized industrial equipment. In general, the most
frequently found symptoms involved the hematological, cardiovascular, endocrine, and nervous
systems of the exposed workers.
In 1970, Glotova and Sadchikova reported the development and clinical course of
cardiovascular changes in 105 workers chronically exposed to 30 GHz, 2000-3000 µw/cm2 (20). They
found that the EMF exposure resulted in cardiovascular and autonomic-system alterations, the nature of
which varied with the individual. In some persons, there was sinus bradycardia and arterial hypotension
without any signs of general or regional hemodynamic disturbances. In others, autonomic-vascular
dysfunctions, often with symptoms of hypothalamic insufficiency were found. Subsequently,
Sadchikova presented dinical observations on the health status of microwave equipment operators (21).
ELECTROMAGNETISM & LIFE - 139