TIME: Almanac 1993/TIME Almanac 1993.iso/time/122490/1224131.000

Text File | 1992-08-28 | 10.5 KB | 226 lines

                                                                                HEALTH, Page 67

Mystery -- and Maybe Danger -- in the Air


A government review heightens concern about hazards of the
electronic age

By PHILIP ELMER-DEWITT -- Reported by Dick Thompson/Washington


    Can electricity cause cancer? In a society that literally
runs on electric power, the very idea seems preposterous. But
for more than a decade, a growing band of scientists and
journalists has pointed to studies that seem to link exposure
to electromagnetic fields with increased risk of leukemia and
other malignancies. The implications are unsettling, to say the
least, since everyone comes into contact with such fields,
which are generated by everything electrical, from power lines
and antennas to personal computers and microwave ovens. Because
evidence on the subject is inconclusive and often contradictory,
it has been hard to decide whether concern about the health
effects of electricity is legitimate -- or the worst kind of
paranoia.

    Now the alarmists have gained some qualified support from
the Environmental Protection Agency. In the executive summary
of a new scientific review, released in draft form late last
week, the EPA has put forward what amounts to the most serious
government warning to date. The agency tentatively concludes
that scientific evidence "suggests a causal link" between
extremely low-frequency electromagnetic fields -- those having
very long wavelengths -- and leukemia, lymphoma and brain
cancer. While the report falls short of classifying ELF fields
as probable carcinogens, it does identify the common 60-hertz
magnetic field as "a possible, but not proven, cause of cancer
in humans."

    The report is no reason to panic -- or even to lose sleep.
If there is a cancer risk, it is a small one. The evidence is
still so controversial that the draft stirred a great deal of
debate within the Bush Administration, and the EPA released it
over strong objections from the Pentagon and the White House.
But now no one can deny that the issue must be taken seriously
and that much more research is needed.

    At the heart of the debate is a simple and well-understood
physical phenomenon: when an electric current passes through
a wire, it generates an electromagnetic field that exerts
forces on surrounding objects. For many years, scientists
dismissed any suggestion that such forces might be harmful,
primarily because they are so extraordinarily weak. The ELF
magnetic field generated by a video terminal measures only a
few milligauss, or about one-hundredth the strength of the
earth's own magnetic field. The electric fields surrounding a
power line can be as high as 10 kilovolts per meter, but the
corresponding field induced in human cells will be only about
1 millivolt per meter. This is far less than the electric
fields that the cells themselves generate.

    How could such minuscule forces pose a health danger? The
consensus used to be that they could not, and for decades
scientists concentrated on more powerful kinds of radiation,
like X rays, that pack sufficient wallop to knock electrons out
of the molecules that make up the human body. Such "ionizing"
radiations have been clearly linked to increased cancer risks,
and there are regulations to control emissions.

    Doubts about weak, so-called nonionizing radiation began to
grow in 1979, when a study of cancer rates among Colorado
schoolchildren found that those who lived near power lines had
two to three times as great a chance of developing cancer. The
link seemed so unlikely that when power companies paid to have
the original study replicated, most scientists expected the
results to be negative. In fact, the subsequent study supported
the original findings, which have since been buttressed by
reports showing increased cancer rates among electrical
workers.

    While many experts still express skepticism, there has been
a definite shift of attitude in the scientific community about
the possible health effects of electromagnetic fields, as a
recent series in Science magazine made clear. "In the 1970's
[the link] seemed absurd,"  the articles concluded. "Now it's
a legitimate open question."

    But epidemiological studies, which find statistical
associations between sets of data, do not prove cause and
effect. Though there is a body of laboratory work showing that
exposure to ELF fields can have biological effects on animal
tissues, a mechanism by which those effects could lead to
cancerous growths has never been found.

    The Pentagon is far from persuaded. In a blistering 33-page
critique of the EPA report, Air Force scientists charge its
authors with having "biased the entire document" toward proving
a link. "Our reviewers are convinced that there is no
suggestion that [electromagnetic fields] present in the
environment induce or promote cancer," the Air Force concludes.
"It is astonishing that the EPA would lend its imprimatur on
this report." The Pentagon's concern is understandable. There
is hardly a unit of the modern military that does not depend on
the heavy use of some kind of electronic equipment, from huge
ground-based radar towers to the defense systems built into
every warship and plane.

    Several Administration officials are also skeptical about
the EPA's conclusions. Last June draft language classifying ELF
fields as a "probable carcinogen" was deleted from an earlier
version of the EPA report after it was reviewed by the White
House. At the time, the EPA denied that it was pressured into
dropping the offending words.

    This time it is clear that the White House is hoping for a
more balanced presentation of the evidence. The draft's release
was reportedly delayed at the request of Allan Bromley,
President Bush's science adviser, who asked that it be reviewed
by another scientific panel and prefaced with a statement that
qualifies the conclusions. In an interview with TIME, Bromley
made it plain that he believes the EPA's findings of a
"positive association" between electromagnetic fields and
childhood cancer are "quite incorrect." "There's no scientific
basis for that statement at all," says Bromley. "What we're
doing is unnecessarily frightening millions of parents."

    The stakes are high. This week a study in the American
Journal of Industrial Medicine reports a steep rise in
brain-cancer rates over the past dozen years. If the increased
incidence of such cancers could be linked to electromagnetism
in the home or workplace, liability suits could clog the
courts. Property values near power lines and electric
substations are plummeting. If the utilities have to bury or
reroute those systems, the cost of doing business could take a
sharp jump.

    How serious is the risk from electromagnetic fields?
Compared with some of the other dangers people take for granted
-- driving a car on New Year's Eve, for example -- the odds of
being afflicted with some of the cancers associated with
electromagnetism are rather small. Brain cancer is a rare
disease. Only 3.1 cases per 100,000 people were reported in
1986. In the most worrisome studies, the risk of developing
such a cancer appears to double or triple because of ELF
fields. By contrast, the risk of lung cancer for a chain smoker
is 20 times as great as it is for the public at large.

    But there is a difference between a smoker who ignores the
Surgeon General's warning and someone who develops cancer
passively just by being born into the electronic age. People
live near power lines and work with their noses in computer
display screens because those things are part and parcel of the
times. Everyone deserves at the very least a rough sense of
what danger such exposure brings.

    More study is essential. The bulk of the research being
conducted on the health effects of electromagnetic radiation
-- at a cost of some $10 million a year -- is paid for by the
Department of Energy and the Electric Power Research Institute,
neither of which is a disinterested party. The EPA used to
conduct its own studies, but funding for its research was cut
off by the Reagan Administration. Perhaps the best candidate
for new funding would be the National Institutes for Health.
The research should examine not only the effects of ELF fields
but also those of less-studied radiation having shorter
wavelengths, such as radio and TV waves.

    Meanwhile, ordinary citizens can exercise what is called
prudent avoidance -- doing relatively easy things to minimize
a possible risk. This is not the time to sell, tear apart or
rebuild a home. But it might make sense to shift a child's bed
away from the electric line that brings power to the house. Or
to move the telephone answering machine away from the head of
the bed. It isn't hard to take a step back from the TV or
computer screen, and it could make a big difference in the long
run.


____________________________________________________________
WHAT TO WATCH OUT FOR


    Probably no individual has collected more information about
extremely low-frequency fields -- or done more to sound the
alarm about the dangers they may pose -- than Louis Slesin,
editor of a newsletter called Microwave News. Here is his
ranking of the worst hazards -- and some advice:

    1. High-tension electric transmission lines. Strung along
high towers, these lines carry large amounts of electricity
over long distances. Homes, schools and playgrounds should not
be built anywhere near them.

    2. Electric distribution lines. The kind that carry current
down local streets, they generate fields less powerful than
those from transmission lines. But distribution line are much
closer to most homes. Utilities can sometimes bury or relocate
the lines.

    3. Electric blankets. They lie right on top of the body for
hours at a time. It's a good idea to warm the bed and then
unplug the blanket before going to sleep -- or better still,
get a quilt instead.

    4. Video-display terminals. People spend whole workdays
close to computer screens. The should stay 75 cm (30 in.) from
the front and 90cm (3 ft.) from the sides and back. The same
rule applies to TVs.

    5. Bedside appliances. Electric clocks and fans usually run
continuously. They should be kept at least 75 cm (30 in.) from
the head.

    6. Other appliances. Shavers, hair dryers, can openers and
microwave ovens all generate powerful fields, and people should
be careful to use them for only short periods of time.