If good government ultimately follows the will of the people, then good
government requires a well-informed public. When the public is misled, seeds
of bad government are sown. This is happening now in regard to three serious
environmental concerns: dioxin, chlorofluorocarbons (CFCs), and asbestos.
In the last few years, the public in effect has been told through mass
media not to worry about the toxicity of tetrachlorodibenzodioxin (dioxin),
the destruction of the ozone layer (resulting in increased UV exposure)
by CFCs, or the carcinogenicity of the chrysotile form of asbestos (which
makes up 95% of asbestos in place in the United States). Overwhelming evidence
from current research strongly suggests that, in all three cases, what the
public is being told is wrong.
Recent popular press reports encourage the public to believe that dioxin,
the inadvertent by-product of the chemical synthesis of certain chlorine-containing
compounds or the incineration of some chlorine compounds, may not be so
dangerous after all.
Dioxin first became famous as the contaminant of the herbicide 2,4,5-T
in Agent Orange used in the Vietnam conflict. It was also found in chemically
contaminated soil at Times Beach, Missouri, and deposited around the Italian
town of Seveso as a result of a chemical plant explosion in 1976.
In the late 1970s, dioxin was shown to be a highly potent carcinogen
in test animals. It also can affect the immune system, alter hormone actions,
and cause a specific skin lesion (chloracne) in humans. Rodents and other
test animals die weeks after a single dose, experiencing decreased food
intake and weight loss. A mechanism to explain the great variability in
the doses that are toxic among species appears to have been found: a mediating
receptor in the cytoplasm.
By the mid-1980s, 2,4,5-T had been banned, other dioxin-generating chemical
processes had been controlled, and Times Beach had been evacuated. However,
in the late 1980s dioxin was found in effluents of paper mills using chlorine
bleach. Some scientists and others associated with the chlorine and paper
industries suggested that the receptor theory of dioxin's mechanism of action
implied a threshold concentration below which dioxin would pose no hazard.
Other scientists, including some from EPA, were considering the same possibility.
Based on these views, on 15 August 1991, the New York Times reported
that exposure to dioxin "is now considered by some experts to be no
more risky than spending a week sunbathing" in a story with the headline
"U.S. Officials Say Dangers of Dioxin Were Exaggerated." Other
major newspapers followed suit with news stories and editorials.
The New York Times story ignored a January 1991 report from Fingerhut
et al. of the National Institute of Occupational Safety and Health that
workers exposed to dioxin for more than 2 years and observed for at least
20 years had a 46% greater cancer death rate than expected. Little effect
was seen after shorter observation periods, which explains earlier studies
finding no effects. Confirming observations were published in the Lancet
by Mantz et al. in the fall of 1991. A 10-year follow-up of those exposed
to dioxin after the chemical explosion at Seveso in 1976, published in Epidemiology
this summer, showed an increase in some cancers. Laboratory scientists continued
to develop still more data suggesting that dioxin is very toxic.
The story of the widely publicized challenge to the role of chlorofluorocarbons
in the thinning of the stratospheric ozone layer, and the resultant increase
in UV irradiation on earth, is neatly told in the 11 June 1993 issue of
Science. Critics--including Dixie Lee Ray, Maduro and Schauerhammer,
and Rush Limbaugh--claim that CFC molecules are too heavy to diffuse up
into the stratosphere (where they destroy ozone) and that volcanic eruptions
inject into the atmosphere many times the amount of chlorine found in CFCs
(thus the increase in chlorine from CFCs must be trivial).
Sherwood Rowland, current president of the American Association for the
Advancement of Science and proponent of the view that CFCs are a major factor
in the destruction of the ozone layer, refutes these claims with hard data.
These data indicate vigorous mixing of CFCs in the atmosphere far above
the stratosphere and rapid washing by rain of most chlorine from volcanic
eruptions. Measured stratospheric increases of chlorine after two recent
major eruptions have been small.
The 19 January 1990 issue of Science carried a well-publicized
report that asbestos exposure in public buildings is being over-regulated.
The argument is made by Mossman and others (most associated with the asbestos
industry) that chrysotile fibers are less toxic than other forms and pose
minimal risk at low doses.
Ignored in the Mossman account are countervailing human data on the carcinogenic
effects of chrysotile asbestos (including large numbers of mesotheliomas
among Canadians) and the finding of mesothelioma, largely from chrysotile
asbestos exposure, among family members of workers who are exposed to low
doses. Moreover, asbestos seldom appears in a pure form, and a threshold
of effect has never been found.
There was little, if any, press coverage of the refutation of the Mossman
article in letters to the editor of Science. With the New York
Times accounts, it seems that not enough knowledgeable scientists were
interviewed to get the whole story. Certainly, few were named. Ties to industry
were not explored. Few of the many letters to the editor challenging the
factual basis for much of the material were printed.
The coverage in Science is somewhat more complicated. Too few
scientists with special expertise on key issues were given the opportunity
to express their views at the same time and in the same issue with equal
prominence and space. After-the-fact letters to the editor have less likelihood
of coverage in the popular press. More careful peer review would have helped.
How do we correct these mistakes in editorial policy and reporting? Most
of the public does not read Science, the Journal of the American
Medical Association, or any other professional journal. But journalists
and publicists who specialize in these issues do. The first line of defense
against bad science and medical reporting is, then, an internal review of
editorial policies and practices of professional journals with a better
focus on the fact that part of the readership is the lay press. A renewed
effort to balance controversial views in the same issue and to invite
letters and commentary for publication in the same issue is a necessity.
The presentation of views by scientists requires vigilance not only on what
is said, but on how and when opposite views are published. These actions
could assist in ensuring that the public is well and accurately informed.
David P. Rall
Founder, EHP
Former Director, NIEHS
Last Update: August 18, 1998