analysis, still being revised, considered more than
3,000 new health studies published since the agency
proposed rules in 1997 intended to cut levels of soot
and other smog ingredients produced mainly by power
plants and vehicles. The proposed rules are still under
review, and the final analysis could be a crucial factor
in the Bush administration's decision about how tough
the final rules should be.
the start, businesses had strenuously fought the rules,
saying the science was suspect and the costs would be
enormous. But in the review of more recent research,
one of the highlighted studies was in fact partly financed
officials said that more changes in the report were
inevitable and another draft was likely before the document
was considered complete. But they said the review clearly
eliminated almost any doubt that this kind of pollution
posed a serious health threat.
is a veritable deluge of new research," said Dr. Lester
D. Grant, the director of the agency's national center
for environmental assessment, in Research Triangle Park,
N.C., which is conducting the review.
bottom line is the studies very substantially confirm
the original findings. That goes a long way toward laying
to rest the sort of controversy that swirled around
far, the Bush administration has not indicated whether
it will change direction on the soot rule. In fact,
President Bush's choice to head the environmental agency's
air division, Jeffrey R. Holmstead, has not yet had
his confirmation hearing.
the administration did take a strong stand on a big
source of this kind of pollution in February, when Christie
Whitman, the E.P.A. administrator, strongly endorsed
a rule drafted by the Clinton administration that would
sharply curtail emissions of soot and other emissions
from diesel engines.
separate standard proposed for soot and air would limit
concentrations of particles smaller than 2.5 microns
to an average of 15 micrograms per cubic meter measured
for three years in a row. Until now, the agency has
only had limits on particles of 10 microns and smaller,
but no specific limit on the smallest ones.
of these particles have been slowly declining on average
across the country for years, as stricter controls have
been instituted on coal- fired power plants and as other
plants have switched to cleaner- burning fuels, particularly
natural gas. But many cities still see dozens of days
each year when levels of the small soot particles far
exceed the proposed federal standard.
example, the study shows that in 1999, the latest year
with comprehensive data, New York City, Los Angeles,
Atlanta, Chicago, and several other cities had annual
average levels of the 2.5-micron particles that would
� if seen for three years in a row � violate the proposed
the early 1980's, scientists' concerns about soot have
focused increasingly on the smallest particles, which
penetrate farthest into the lungs.
1987, regulations took effect that limited the concentration
in air of particles less than 10 microns in diameter
(a human hair is about 100 microns across). But the
rule proposed in 1997 would sharply reduce allowable
levels for particles less than 2.5 microns across.
microscopic motes � composed of metals, carbon and other
ingredients � are able to infiltrate the tiniest compartments
in the lungs and pass readily into the bloodstream and
have been most strongly tied to illness and early death,
particularly in people who are already susceptible to
critical new research effort cited in the E.P.A. review
was an analysis by an industry-financed research center,
the Health Effects Institute, that supported the conclusions
of two keystone studies from the early 1990's that drove
the agency to write the new rule.
studies, by the Harvard School of Public Health and
the American Cancer Society, found strong links between
high levels of small particles and a rise in death rates.
They were attacked by industry groups and some members
of Congress as biased.
Health Effects Institute, based in Boston, is financed
by industry and the E.P.A. and was established in 1980
to serve as a referee on air pollution research. Its
study, published last year, largely approved of the
methods and data in the original studies and concurred
that there was a link between soot and illness.
other new studies, Dr. Grant said, corroborate the link
between the smallest particles, those under 2.5 microns,
and the most serious health effects. Other studies cited
in the new analysis strengthen the relationship between
sooty conditions and a rise in hospital admissions of
children with asthma attacks.
632-page research review, which was posted on the agency's
Web site (www.epa.gov/ncea/) this month, has already
been through one round of public comments and a critique
by an agency panel that includes officials from industries
that generate some of the pollution.
second round of public comment will end in July, followed
by another critique by the panel, the agency's Clean
Air Science Advisory Committee. The agency is also beginning
to draft a paper recommending how to translate the findings
into the final language of a rule to cut fine soot.
Mrs. Whitman, assessing the science and her staff's
recommendations, would propose either to accept the
Clinton administration standard or to modify it. Some
supporters of strict controls decried the pace of the
rule making, which has been delayed by court challenges,
including one from the American Trucking Association
and other industry groups that was rejected by the Supreme
Court in February.
already having another scientific review completed before
step one has actually been taken to cut the pollution,"
said David G. Hawkins, a lawyer for the Natural Resources
Defense Council, a private group. "In the meantime,
there are about a quarter million Americans who have
died prematurely as result of fine particle exposure."
including some cited in the new review and one by the
natural resources group, have estimated that more than
50,000 people die prematurely each year from illnesses
caused by exposure to fine soot.
delays are expected, agency officials and environmental
groups said, both because of other litigation and a
law passed last year that could allow the Office of
Management and Budget to review the quality of the data
underlying the studies cited by the agency to justify
the voluminous nature of the document, industry representatives
said the E.P.A. analysis was basically a laundry list
of existing work. With the regulation likely to cost
industry billions of dollars a year, trade groups are
demanding to see not only the studies, but also the
raw data underlying the work.Agencies have generally
not had to go to such lengths, which would require enormous
amounts of paperwork.
going to have to sit down and go over what the E.P.A.
is basing its decision on and what other documents are
out there," said William L. Kovacs, the vice president
for environmental, technical, and regulatory affairs
of the United States Chamber of Commerce, a lobbying
they really believe so strongly in the data, then why
don't they release it? If it's that compelling, I'd
be plastering it on the walls."