Tuesday, October 23, 2007

Experts Disagree on Asbestos Risk in NYC

Unprotected workers may develop mesothelioma

The pictures are vivid: office workers, firefighters, and police coated in gray dust after the collapse of the World Trade Center in New York. The immediate effects were obvious: people choking, coughing, and gasping. Now, however, people are starting to wonder about the long-term health effects of that day. News agencies have reported that the steel trusses supporting the lower floors of the Trade Center's towers were sprayed with hundreds of tons of asbestos-containing fire retardants during construction in the 1960's, before the hazards of asbestos were known.

Bonnie Bellow, director of communications for the New York regional office of the Environmental Protection Agency (EPA), stated that nine air samples near "ground zero" the day after the collapse produced no detectable levels of asbestos. Of the four dust samples taken so far, three showed safe levels of asbestos (below 1 percent). However, a fourth sample was composed of about 4 percent asbestos, much higher than what's considered safe. Some medical experts would say there is no safe level of asbestos that can be breathed in.

Experts disagree on risk
If workers wear special masks (respirators) and protective suits, and change out of the suits before leaving, this usually provides adequate protection against breathing in asbestos. The EPA provided 3,000 respirators and 10,000 protective suits for rescue workers at the site to use. Ms. Bellow stated that any danger from asbestos would be confined to those unprotected emergency workers right at the scene of the collapse.

Phillip Landrigan, chairman of the department of community and preventive medicine at the Mount Sinai Medical Center in NewYork and a leading expert on occupational diseases, stated that over the long term the rescue workers at the World Trade Center are likely to have a higher incidence of mesothelioma, a rare lung cancer. He stated in an interview that when firefighters are extinguishing fires they wear their masks, but when the fire is out "the mask is off, the asbestos is there, they kick it up and inhale it." More than 15 percent of New York firefighters in a recent study were found to have asbestos-related diseases.

Dr. Mark Siegel, an expert in pulmonary medicine at Yale School of Medicine and director of the Medical Intensive Care Unit at Yale New Haven Hospital, has a different view. Asbestos usually causes illness with repeated exposure to it over long periods of time. "So a single isolated asbestos exposure, even if it was large in quantity, would be unlikely to cause major lung damage," he stated in an interview.

What's at stake
Asbestos fibers, when inhaled into the lungs, stay there and cause irritation and scarring (asbestosis) and lung cancer. The tissue lining the chest, abdomen, heart, and reproductive organs (mesothelium) can also become cancerous (mesothelioma). Asbestos exposure is the major known cause of mesothelioma (70-85% of cases). About 2,000 new cases of mesothelioma are diagnosed each year. There is no cure.

One of the difficulties in determining who may develop mesothelioma is that it does not show up for 20, 30 or even 50 years after exposure to asbestos. There are no early warning signs, and the symptoms--shortness of breath, chest pain, weight loss, or abdominal pain and swelling--may be mistaken for any number of other medical problems.

Watch and wait?
Perhaps the best answer at this time to the question, "Will the unprotected rescue workers develop mesothelioma?" is, "No one knows for sure." Some individuals with only brief exposures to asbestos have developed cancer, and not all asbestos workers who are heavily exposed develop lung disease. Unfortunately, only time will tell.

Information for this article was taken from:
- Cook, G. and Robertson, T. "Asbestos dust poses threat to rescue crews." The Boston Globe, 9/14/01.
- Gordon, G. "A new threat in New York: asbestos." Star Tribune, 9/14/01.
- National Cancer Institute. Questions and Answers About Mesothelioma. Available online.
- National Institute for Occupational Safety and Health, Centers for Disease Control. Congressional Testimony of Kathleen M. Rest, Acting Director, Before the United States Senate, on Workplace Exposure to Asbestos, July 31, 2001. Available online.
- Reuters Medical News. "Health effects of World Trade dust cloud may linger." Medscape.com, 9/12/01.


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