Environment specialists told New York workers and residents last week that early studies of asbestos and lead levels in the dust at the site of the collapsed World Trade Center showed that they were below danger levels.
The specialists also described some studies that are going to be carried out to follow the affected population. The studies will involve two child health centres at Columbia University and Mt Sinai Medical Centre and four environmental health centres at Columbia University, New York University, the University of Medicine and Dentistry of New Jersey, and Johns Hopkins University in Baltimore.
The experts addressed a community meeting last week of more than 200 people at a New York University auditorium in Greenwich Village, about a mile north of the disaster site, which is still burning. The affected population includes many thousands who work in the financial district, at least 2000 who live nearby, rescue workers, workers who will be cleaning up the site for months, and several hundred pregnant women who work at or live close to the site.
Dr George Thurston, professor of environmental medicine at New York University, said that so far levels of asbestos and lead were below the levels of concern set by the US Environmental Protection Agency.
Although preliminary analyses of the dust coating streets, offices, and residences in lower Manhattan had been carried out, more studies are still to be done. The risks of the dust to children and pregnant women are also to be evaluated, as are the odours that disturb residents and workers now back in the area.
The dust, said Dr Paul Lioy of the New Jersey Medical School, is white, powdery, and fluffy. It will be analysed for content and then researchers will try to reconstruct the plume of smoke that spread dust to see whether levels of pollutants differ in different areas. He advised having homes and offices cleaned by certified asbestos removal experts and checked afterwards for asbestos levels.
Preliminary analysis of dust showed that levels of chrysotile asbestos ranged from 0.3% to 0.8%; 1% is the "action level." Amosite asbestos levels were zero. Cellulose in dust samples ranged from 5% to 13%; mineral wool ranged from zero to 40%; and non-fibrous material was 45-50% in some samples, up to 90% in very fine particles.
Lead paint particles were found in the dust—although at low levels—because lead paint had not been banned until after the buildings had been built.
Residents and workers in the financial district asked about the stench that they smelt daily and which was worse at night, even invading buildings. People said it smelt like "burnt rubber" or "burnt electrical cables." Dr Thurston explained that the sun warmed the site during the day, causing pollutants to rise, mix, and diffuse with the air. At night, however, when air was cool, pollutants were unmixed and smelly, although they were still below allowable limits.
Stress is a risk for preterm birth, and studies will include the several hundred pregnant women working or living in the area. The Mt Sinai-New York University medical centres see about 5000 pregnant women a year. Columbia-Presbyterian Medical Center has been monitoring the health of pregnant women and their babies in northern Manhattan, many miles north of the disaster site. Their health and outcomes will be compared with those of women close to the site.
