Maxwell's Silver Hammer 309
at that time, research suggested this was an unsafe level, a fact recog-
nized by Consumers Union in 1973 when it recommended against the
purchase of any brand. Leakage surveys have shown that all types put
out an average of 120 microwatts near the door, while many emit much
higher amounts. A worn seal or piece of paper towel stuck in the door
can increase the user's exposure to well over the 5,000-microwatt level,
according to Consumers Union tests.
What amounts of electromagnetic energy do workers and the general
public actually absorb? The levels vary greatly. Some antenna repairers
receive up to 100,000 microwatts for minutes or hours during a job.
Many factory workers are in the same bracket. From 1974 to 1978
NIOSH surveyed eighty-two industrial plastic molders and sealers. Over
60 percent exposed the operator to more than the Schwan limit, some to
over 260,000 microwatts. Because of low wages for such work, nearly
all sealer operators are women of childbearing age. NIOSH has esti-
mated that some 21 million workers are exposed to some level of radio-
frequency waves or microwaves as a direct result of their jobs. No metal
shielding is provided for most workers in this country, although it's sold
to other nations having better safety rules.
At this time there's no way to estimate how much EMR people are
getting away from their jobs, because the few readings that have been
taken have measured only single sources and single frequencies. No one
has yet surveyed our cities and countryside throughout the whole spec-
trum from ELF to microwaves. All we know is that most people's daily
exposure is high. Even the Environmental Protection Agency has esti-
mated that if the Soviet off-the-job safety limit of 1 microwatt in the
radio and microwave bands was adopted here, over 90 percent of our FM
stations would have to be shut down.
Table 1. Power Density at Various Distances from a 50,000 Watt
AM Radio Station
Distance
(feet)
Power
Density
(microW/cm2)
Distance
(feet)
Power
Density
(microW/cm2)
15
838
482
23
29
284
663
12
69
196
1571
2
152
43
3280
1
308
33
5760
0.3
Note
Data from R. Tell et al., "Electric and Magnetic Field Intensities and Associated
Body Currents in Man in Close Proximity to a 50 kW AM Standard Broadcast Station,"
presented at Bioelectromagnetics Symposium, Seattle, 1979.