ABSTRACT
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 November 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 (SO2)—can blow from country to country, and continent to continent.
