exerpted by Tom Gray (tomgray@AT@econet.org) from the American Wind Energy Association's publication Wind Energy Weekly
Particulate pollution deadly
A study of the health records of more than half a million people in 151
cities around the U.S. has found that high levels of particulate
pollution from autos, power plants, and other sources cause a
significantly higher risk of death.
The study, carried out by researchers from the Harvard School of Public
Health and Brigham Young University, was reported in the March issue of
the American Journal of Respiratory and Critical Care Medicine. It found
that people in the nation's most polluted cities are 15 to 17 percent
more likely to die prematurely than those living in cities where the air
Study co-author Douglas Dockery of Harvard said the study indicates that
"the impact of life and health [of particulate pollution] is more
pervasive than previously thought."
Fine particulates, defined as particles of dust, smoke, soot, or acid
less than 2.5 microns in diameter, have not been studied as extensively
as chemical emissions such as sulfur dioxide, ozone, and nitrogen
oxides. They are produced by a variety of sources, including coal- or
oil-fired power plants, wood burning, and even dust from farms. In the
eastern U.S., power plants are the chief source, while in the west,
nitrogen compounds from autos predominate.
Researchers speculate that particulates are deadly because they can be
breathed deeply into lung tissues. If the lungs' efficiency is damaged,
the heart must work harder to compensate, and elderly people with heart
or lung problems are more vulnerable during periods of extreme weather
or pollution conditions.
The new study is important because it covered so many subjects. Its
large size allowed the authors to screen out many other possible sources
of increased mortality such as smoking, alcohol, and high blood
While the federal Clean Air Act has reduced emissions of a number of
different types of pollutants, fine particulates are not currently
regulated. The American Lung Association sued the U.S. Environmental
Protection Agency (EPA) last year in a bid to force the agency to
develop emissions limits for fine particulates. A federal court has
given the EPA until 1997 to determine whether a limit is needed. Dr.
Philip Landrigan of Mount Sinai Medical Center told the New York Times
that the new study "makes an airtight case" for an emissions standard on