Geoscience Reference
In-Depth Information
Chapter 14
The Global Sweep of Pollution
Bob Weinhold
INTRODUCTION
Towering smokestacks were a popular mid-20th century “remedy” for industrial
emissions. Pump the stuff high enough into the air, went the thinking, and the problem
would go away. But evidence collected since then has strongly suggested that tall
smokestacks are not sufficient to mitigate the effects of pollution—those pollutants
eventually came down somewhere, dozens or thousands of miles away. In the Novem-
ber 2006 issue of EHP, for example, Morton Lippmann of the New York University
School of Medicine and colleagues reported a strong link between nickel emitted from
a very tall smokestack at a smelter in Sudbury, Canada, and acute heart rate changes
in mice some 500 miles away. At the same time, we also now know that tall stacks are
not necessary for pollutant emissions to waft great distances, as verified by scores of
individual studies showing that one pollutant or another—such as ozone, particulate
matter (PM), and sulfur dioxide (SO
2
)—can blow from country to country, and conti-
nent to continent.
Beginning in the 1980s and accelerating since about 2000, satellite surveillance
with increasingly sophisticated instruments has enabled us to better visualize the
complex fl uctuations of several important pollutants as they ebb and fl ow around the
planet. This new capability is partly serendipitous. “Most of these satellites weren't
designed to have an air quality focus,” says Terry Keating, an environmental scientist
with the US Environmental Protection Agency (EPA) and co-chair of the Task Force
on Hemispheric Transport of Air Pollution, which was created in 2004 by the United
Nations Economic Commission for Europe's Convention on Long-range Transbound-
ary Air Pollution. “But we fi nd ourselves with this stream of data, and we are fi guring
out how to use it,” he says.
One use has been a handful of pilot projects directly linking satellite-observed
column-wise concentrations of atmospheric pollutants—that is, the concentration
from the Earth's surface to the top of the atmosphere—with concentrations at the
ground level. “Only in the past ten years have we been able to advance epidemi-
ological science with satellites,” says John Haynes, program manager for public
health and aviation applications at the National Aeronautics and Space Administra-
tion (NASA). “This is truly a leap forward into the twenty-fi rst-century science of
epidemiology.”
