Pollutant levels in lower Manhattan after Sept. 11 may have been higher than those reported by previous researchers, according to a study by Canadian scientists.

Six weeks after the 2001 World Trade Center attacks, film found on windows within one kilometer (.62 miles) of Ground Zero revealed high levels of PCBs, flame retardants and other organic pollutants. Concentrations of the chemicals were up to 10 times greater than New York City's normal background levels and possibly 100 times higher than surrounding rural areas.

The report is scheduled to appear in the July 1 print edition of Environmental Science & Technology, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.

"We were very concerned just after 9/11, as were most people in North America," says Miriam Diamond, a professor in the Department of Geography at the University of Toronto and lead author of the paper. "We were sitting around the lab shortly after the attack and said, 'Why don't we go down and use our simple method to see what the contaminant levels are like?'"

Diamond's method involved "washing a bunch of windows" in lower Manhattan and then analyzing the resulting samples for four potentially toxic organic pollutants: polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs).

"All the samples within one kilometer of the World Trade Center were high," Diamond says. "For the PAHs, PCNs and PCBs, they were about a factor of 10 relative to Brooklyn." A site in Brooklyn was used as a baseline for the New York City area because of its location 3.5 kilometers upwind of the towers.

Diamond's earlier research in Toronto showed a similar factor of 10 difference between window films in urban and rural locations, so the concentrations near Ground Zero could have been as much as 100 ti
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Contact: Michael Bernstein
m_bernstein@acs.org
202-872-6042
American Chemical Society
3-Jun-2004