ACSH: PCB's cause cancer?

Gary Greenberg Gary.Greenberg at Duke.edu
Wed Dec 13 01:28:31 EST 2000


American Council on Science and Health 

http://www.acsh.org/press/editorials/pcb121200.html

(Moderator Note: ACSH is an organization routinely dubious about new
claims of environmental health dangers. Their editorials & press
releases are presented to the OEM-L forum in an effort to provoke
intellectual discussion, not as an endorsed point of view. For contrast,
see the newsletters posted from RACHEL. -G)

Published in Wall Street Journal—December 12, 2000 

Who Says PCBs Cause Cancer? 

by Elizabeth M. Whelan 

Last week the Environmental Protection Agency proposed that General
Electric spend $490 million dredging the Hudson River to remove what are
known as polychlorinated biphenyls, or PCBs. 

Until 1977, PCBs were used in the manufacture of transformers, adhesives
and capacitators, among other things. GE legally dumped them into the
river north of Albany for decades. The PCBs are now embedded in the mud
beneath the Hudson, and are not generally dispersed in the water. 

Media coverage has been murky as to exactly what the EPA hopes to
accomplish with half a billion dollars of dredging. To clarify the
agency's intent, I contacted EPA official Kevin Matthews. He explained
that the EPA was worried about both the "health of the river" and about
human health problems, particularly an increased risk of cancer from
eating Hudson River fish. 

But contrary to EPA assertions, there is no credible evidence that PCB
exposure in the general environment, in fish, or even at very high
levels in the workplace, has ever led to an increase in cancer risk.
While reasonable people have suggested that dredging would displace
buried PCBs and make matters worse, at this point we have no evidence
that even high-level human exposure to PCBs causes any problem other
than eye and skin irritation. 

The EPA's assertion that PCBs in fish pose a human cancer risk is based
solely on observations that high-dose, prolonged PCB exposure causes
tumors in laboratory animals. But this is very different from the
question at hand: Is there any evidence that the traces of PCBs in
Hudson River fish increase the risk of cancer in humans? The EPA, an
environmental regulatory agency, isn't known for its competency in the
scientific discipline of cancer causation. We therefore need to turn
elsewhere for expert opinions on any causal relationship between PCBs
and cancer. 

An examination of the bible of cancer causation, "Cancer Epidemiology
and Prevention" by David Schottenfeld and Joseph F. Fraumeni Jr.,
reveals no reference whatsoever to PCB-containing fish (or any other
source of PCBs) causing malignancy. This 1,500-page volume focuses on
real human cancer risks, like tobacco use and overexposure to sunlight.
But perhaps the ultimate authority on cancer risk is the National Cancer
Institute. I put the question to the institute's director, Richard
Klausner: Does NCI have any evidence that eating fish from the Hudson
River contributes to the toll of human cancer? 

This wasn't the first time I'd queried Dr. Klausner on cancer causation.
Over two years ago the organization I head up, the American Council on
Science and Health, composed (and had peer-reviewed) a similar, but
broader, question for which we unanimously agreed the answer was no.
(ACSH is an independent consortium of 350 physicians and scientists,
funded by private foundations and corporations, including the GE fund,
which accounts for about 1% of the group's total budget.) 

Specifically, we asked Dr. Klausner: "At this time, does the NCI know of
any credible scientific evidence that exposure to trace levels (parts
per million or less) of synthetic chemicals in the general
environment—even if these chemicals have been shown in high dose to
cause cancer in laboratory animals— contributes to the toll of human
cancer in the U.S.?" 

As should now be obvious to GE and every other U.S. manufacturer, this
is much more than a theoretical question. It has immediate, practical
and costly implications. Congress, for example, has passed laws based on
the premise that a "mouse is a little man." One, the "Delaney Clause,"
states unequivocally that any synthetic food chemical that causes cancer
in lab animals must be assumed to pose a human cancer risk—no matter how
minimal the human exposure—and must be banned. Similarly, California's
Proposition 65 requires that all consumer products containing even trace
levels of animal carcinogens be banned or labeled. In short, decisions
are being made, and limited resources are being committed, based on the
assumption that trace exposures to animal carcinogens like PCBs pose a
human cancer risk and must not be tolerated, no matter what the cost. 

For over two years, NCI has refused to answer our original question.
Presumably NCI has been resisting stating the obvious—that there is no
evidence that trace levels of animal carcinogens pose a human cancer
risk—to avoid a head-on collision with the EPA, which for decades has
been on a regulatory carcinogen witch hunt. 

This week, however, the National Cancer Institute found its voice. Susan
Sieber, a scientist and director of communications, told me that the
institute knew of "no evidence" that eating fish from the Hudson River
posed a human cancer risk. Why should we tolerate government policies
that purport to prevent cancer by targeting environmental risks our
nation's top cancer experts say don't exist? 

Elizabeth M. Whelan is president of the American Council on Science and
Health. 

If you wish to respond to this editorial please email your comments to
forum at acsh.org, or visit the ACSH FORUMS at
www.acsh.org/forum/chemicals/index.html to post them directly.

The American Council on Science and Health is a consortium of more than
350 scientists and physicians dedicated to consumer education on public
health issues, such as the environment, nutrition, and pharmaceuticals.
ACSH attempts to illuminate the difference between real health risks and
hypothetical or trivial health scares. 


-- 
Gary N. Greenberg, MD MPH    Sysop / Moderator Occ-Env-Med-L MailList
gary.greenberg at duke.edu     Duke Occupat, Environ, Int & Fam Medicine
OEM-L Maillist Website:                      http://occhealthnews.com


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