A team of researchers tested debris from the collapsed towers for toxic organic chemicals and found that the potential risk of exposure from inhaling such compounds was lower than expected. The findings are scheduled to appear in the Feb. 1 print edition of Environmental Science & Technology, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society. The article was initially published Dec. 18 on the journal's Web site.
The scientists were looking specifically for persistent organic pollutants highly stable compounds that pose a special problem because they endure in the environment and can be toxic to humans and wildlife. They found no evidence of high levels of two particular POPs: pesticides and polychlorinated biphenyls, which were used in hundreds of industrial and commercial applications until their production was banned in 1977.
The team did, however, estimate that the dust covering lower Manhattan contained between 100-1000 tons of polycyclic aromatic hydrocarbons a group of compounds containing some that are classified by the U.S. Environmental Protection Agency as probable human carcinogens. But, while the amount of PAHs was high, the dust particles to which the chemicals stuck were large enough to stay out of a person's lungs, according to Paul Lioy, Ph.D., associate director of the Environmental and Occupational Health Sciences Institute in Piscataway, N.J., and an author of the paper.
"The fact that the particles were primarily above 10 micrometers in diameter would mean that the deposition was in the upper airways of the respiratory system and more readily cleared than fine par
Contact: Beverly Hassell
American Chemical Society