Soot to Heart Disease
Trigger Defense Mechanisms
That Tend to Clog Arteries
By JOHN J.
Reporter of THE WALL STREET JOURNAL
WASHINGTON -- New research on the health effects of air
pollution showed for the first time that tiny airborne soot particles such as
those produced by power plants and diesel engines can be directly linked to
certain types of heart disease.
The findings, part of the largest air-pollution study done to
date, show how "low grade inflammation" caused by soot imbedded in
the human lung triggers defense mechanisms that tend to clog arteries and
lead to chest pain, irregular cardiac rhythms and heart attacks.
"This affects far more people than [who] die of lung
cancer or even all other lung diseases," said C. Arden Pope III, an
epidemiologist from Brigham Young University in Provo, Utah, and leader of a
team of seven scientists who worked on the study, which was financed by the
National Institute of Environmental Health.
The findings, according to Dr. Pope, "validate"
regulatory efforts by the Clinton and Bush administrations to reduce fine
particles of soot in the nation's air. But he added that they also raise
doubts about a Bush administration regulatory change to prolong the operation
of older, coal-fired power plants, called "New Source Review."
Dan Riedinger, a spokesman for the Edison Electric Institute,
which represents most of the privately owned utilities in the U.S., asserted
that "the most comprehensive research conducted in this area so far has
found that power plants aren't the pollution source at issue here." He
argued that cutting power-facility soot emissions further may not result in
added health benefits. A spokesman for the American Trucking Association said
it had no comment on the Pope study.
The Environmental Protection Agency says coal-fired power
plants and diesel engines are the major producers of soot particles less than
2.5 microns in diameter. Similar in size to particles in cigarette smoke,
fine soot can float on air currents for thousands of miles. Fine soot
contains sulfates, carbon and nitrates and can include other contaminants,
such as arsenic, cadmium, mercury and lead.
The Pope study, published Tuesday by Circulation, the journal
of the American Heart Association, says the particles can cause inflammation
of lung tissues. The inflammation, in turn, triggers a range of defense
mechanisms including an increase in sticky blood platelets that can clog
arteries leading to the heart.
Earlier scientific efforts had attributed the same problem to
high levels of cholesterol in the blood, but inflammation from soot, Dr. Pope
explained, "plays a bigger role than we ever understood before in terms
of these fatty plaques."
Previous researchers also thought that soot contributed more
to lung disease, rather than heart disease, which is a much bigger cause of
premature deaths. The new study tracks the causes of death of more than
319,000 people in all 50 states and relates the findings to air-pollution
levels in their communities. It uses a computer program to weigh the relative
effects of other disease factors, such as smoking, body mass, diet and
occupational exposures to pollutants.
"This is the clearest link yet between fine particle soot
and the reason that tens of thousands of Americans are dying
prematurely," said Frank O'Donnell, the head of Clean Air Trust. Earlier
air-pollution regulations, according to the Pope study, have helped reduce
the average load of fine soot in the air by as much as a third. However, Dr.
Pope noted, "what is harder to know is when the air is clean
In 1997, the Clinton White House proposed the first
soot-emissions controls on power plants, rules scheduled to go into effect in
2005. Since then, both the Clinton and the Bush administrations have
introduced regulations to reduce the soot emissions of diesel trucks and
off-road construction equipment, moves that will phase in after 2007.
In other pollution-related action Monday, EPA said it is about
to release final versions of two proposed regulations that would cut mercury
emissions from power facilities and make deep cuts emissions of sulfur
dioxide and nitrogen oxides in the Eastern U.S.
Sulfur dioxide and nitrogen oxides are major contributors to
soot levels, which are carried from power plants and other sources in
Southeast and Midwest to further complicate pollution problems in East Coast
Write to John J.
Fialka at email@example.com