cataracts. In 1963, in one of the earliest studies of this relationship between EMFs and ocular
anomalies, Zaret et al. (43) examined 73 6 workers involved in the maintenance and testing of radars,
and 559 control individuals. The ophthalmic examinations included visual acuity tests, slit-lamp
examinations, and stereophotography of the lens. They found significant differences between exposed
and control groups in the frequency of polar defects and opacities. Subsequent re-evaluations of Zaret
et al.'s data reinforced the original conclusions (44,45).
Mejewska (46) studied 200 workers who were exposed to 0.6-10.7 GHz and 200 control
individuals: a statistically significant increase in lens opacities in the exposed individuals was found.
The severity of the disease increased with the duration of exposure. In another study, which involved
600 workers and an age-matched control group of 300 individuals (47), it was found that exposure to
0.3-300 GHz correlated with an increased incidence of a specific kind of lens opacity. Appleton
surveyed military personnel who had been exposed to microwave EMFs and found a trend in older age
groups toward a greater incidence of opacities among exposed personnel (48). Odland (49) also studied
the relation between exposure to military radars and ocular anomalies. There were 377 exposed
individuals and 320 controls: among the exposed workers who had a family history of eye diseases, it
was found that the incidence of eye defects was almost twice as great as that among the controls who
had such a family history. Among 68 electronics workers and 30 control individuals, it was found that
the incidence of lens opacities and retinal lesions were both greater in the exposed group (50, 51).
Zydecki studied 1000 exposed workers (mostly between 100-1000 µW/cm2) and 1000 controls and
found that the number of lenticular opacities was significantly greater in the exposed individuals (52).
Through painstaking analysis of many clinical cases, Zaret has been able to describe a particular
lens opacification for which EMFs are the primary etiological factor (the microwave cataract) (53 -57).
In contrast to other types of cataracts (heredity, metabolic, and senile) which originate in the lens, the
microwave cataract originates in the elastic membrane that surrounds the lens (the capsule). Microwave
cataracts occur following exposure to either thermal or nonthermal EMFs, and have a latency period of
months to years.
The Soviet Union has enacted a high-frequency EMF occupational exposure limit of 10
µW/cm2 (58). Since the general public is a much more heterogeneous group than the work force-which
does not generally contain the very young or old, or the sick-an additional safety factor of ten was
incorporated in choosing a standard for the general environment, which was set at 1 µW/cm2 (59).
Personnel working in electrical sub-stations or near high-voltage power lines are exposed to
relatively intense power-frequency electric and magnetic fields. In the early 1960's, Soviet scientists
conducted several studies of the effects of power-frequency EMFs on exposed workers (60-62) and
found a variety of ills including headaches, fatigue, chest pains, and sexual impotence. These studies
led to the first (and only) health standards designed to regulate exposure to power-frequency EMFs in
the workplace (63) (Table 10.7). Spanish investigators found similar problems among 9 workers (64),
but among 11 American service personnel the only finding was a reduced sperm count in 2 workers
(65).
Table 10.7. SOVIET OCCUPATIONAL-EXPOSURE SAFETY LEVELS FOR POWER-FREQUENCY
ELECTRIC FIELDS
ELECTROMAGNETISM & LIFE - 141