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Dioxin News Article
This article appeared in the October 1, 1995, edition of the Charleston
Gazette (Charleston, WV).
EXPERT PANEL BACKS EPA DIOXIN STUDY
By Ken Ward Jr.
An independent panel of scientists has given its general approval to the
conclusions of a three-
year U.S. Environmental Protection Agency study of the toxic chemical dioxin.
According to a summary and several key chapters of its report obtained
last week, a committee
of EPA's Science Advisory Board has found that:
* EPA was right to conclude that almost all dioxin currently found in the
created by human - i.e., industrial - sources, not natural causes like
* The agency was correct in finding that dioxin is properly classified as
a probable human
carcinogen, according to data from both animal and human studies. This
designation is more
serious than the current EPA classification for dioxin.
* As EPA concluded last September, dioxin can cause serious harmful
effects on the immune,
nervous and reproductive systems of humans. In fact, these non-cancer
effects may be more
serious than dioxin's ability to cause cancer.
* Dioxin, as EPA outlined, does have adverse effects on animals at levels
of exposure far below
those previously believed to be safe.
A final version of the Science Advisory Board report was expected to be
delivered to EPA
Administrator Carol Browner on Friday, according to agency officials.
EPA scientists will study the peer review team report and then issue a
final dioxin report
sometime next year.
"I don't think their report will bring about major changes in our
conclusions," said William H.
Farland, an EPA scientist who helped write the agency's dioxin report.
The public release of this full peer review report, expected soon after
Browner reviews it, will
probably start another media and political war over the agency's
Environmental groups, who believe EPA's conclusions should mandate
tougher dioxin regulations,
are braced for another blitz from the chemical and paper industries that
oppose such measures.
They say several criticisms of EPA by Science Advisory Board will be
plucked form the panel's
report and used to push the message that the dangers of dioxin are being
In fact, some environmental groups say, parts of the committee's report
were written for that
purpose by committee members who received research money from industries
that would be
hurt by stronger dioxin rules.
Former EPA Administrator William Reilly launched the EPA dioxin
reassessment in April
1991 after a series of industry-sponsored reports alleged the dangers of
the chemical had been
In September 1994, EPA officials in Washington, D.C., unveiled a public
review draft of their
report. It filled six thick books containing more than 2,000 pages.
The report concluded that there may be no safe level of dioxin and that
the range of adverse
health effects was much broader than just cancer.
The peer review report from the Science Advisory Board generally endorsed
the EPA report's
first eight chapters, which examined the sources, exposure levels and
health effects of dioxin.
The committee agrees with the EPA position that current levels of
dioxin-like compounds in
the environment are due to anthropogenic sources, and based on available
data, that the air-to-
plant-to-animal pathway is the primary way in which the food chain is
impacted and humans
are exposed," the committee's &aft report stated.
The committee also suggested EPA needed to do more work on the models
extrapolate high-dose dioxin exposure of industrial workers, and on
animal tests to low-dose
average human exposures.
Perhaps the most controversial sections of the peer review report will be
those that examined
Chapter 9 of the EPA's reassessment.
This chapter, called the risk characterization chapter, was intended to
provide "a balanced
picture of the scientific findings of the health and exposure assessments
for use by risk
managers in selected risk management options," the EPA draft study said.
In its review of this chapter, the Science Advisory Board committee
praised EPA for focusing
serious attention on non-cancer effects, examining dioxin and similar
and stating specifically that the new study found adverse health effects
occurring at much
lower levels of exposure than previously reported.
But the panel also noted what it called three major weaknesses in Chapter
9 of the
* EPA failed to present scientific findings in a balanced manner and
tended to overstate the
evidence of danger. For example, the inference that humans are at risk
from average current
exposure levels of dioxin was based on populations that are at the high
end of these average
current exposure levels.
* Important uncertainties associated with EPA's conclusions were not
fully recognized and
subjected to analysis. For example, EPA consistently used conservative
numerical values - those
aimed at being more, rather than less, protective - for dioxin potency.
* EPA did not provide specifics about how much dioxin exposure would
cause which of the
many non-cancer effects identified in the report.
This section of the peer review report was written primarily by John
Graham of the Harvard Cen-
ter for Risk Analysis and William Greenlee, formerly of Purdue University
and now with the
University of Massachusetts at Worcester, according to EPA officials.
During the 1993-93 academic year, Greenlee received nearly $1 million in
research grants from
the industry lobby group the American Forest & Paper Association,
according to a Purdue
University annual report. According to the report the grant was for a
project called "De-
velopment of a Biological Basis for Dioxin Risk."
A secretary at Greenlee's current office in Worcester said Greenlee
wished to refer questions
about the peer review report to Sam Rondburg, a staff member of the
Science Advisory Board.
Barry Polsky, a media spokesman for the trade group, noted that the EPA
was aware of where
Greenlee's research grants came from.
"There was complete disclosure of that and we don't see conflict of
interest," Polsky said Friday.
Stephen Lester, science director for the Citizens Clearinghouse for
Hazardous Waste, said two
scientists with ties to national environmental groups recused themselves
from the Science
Advisory Board review of the dioxin study because the groups they work
with had taken public
stands on dioxin policy.
Lester wonders why Greenlee didn't do the same thing.
"The science end of this is sound," Lester said. "But it has become a
complete circus that is
dominated by the corporations and their money."
Citizens Clearinghouse for Hazardous Waste