TORONTO, June 4 (UPI) -- Canadian scientists report pollutant levels found on windows in lower Manhattan, N.Y., after Sept. 11, 2001, may have been higher than previously reported.
Researchers at the University of Toronto found high levels of polychlorinated biphenyls or PCBs, flame retardants and pollutants in dust film on windows from nine buildings within a little over a half-mile from Ground Zero six weeks after the attack.
Pollutant concentrations were up to 10 times higher than New York City's normal background levels. This probably means levels of up to 100 times higher than in New York suburbs, based on prior research, wrote Miriam Diamond, the study's lead author.
Shortly after Sept. 11 scientists had found no evidence of PCBs and little risk of health threats from pollutants.
Diamond said earlier researchers may have detected lower levels because their samples were diluted by building matter still up in the air. She found pollutant concentrations dropped to background levels beyond the half-mile or so from Ground Zero.
