Will the workers hauling debris from Ground Zero experience long-term health problems from the polluted air at the disaster site? That's the question that John Groopman, PhD, professor and chair of the Department of Environmental Health Sciences, and Alison Geyh, PhD, will now be able to explore, thanks to a $400,000 grant from the National Institute of Environmental Health Sciences (NIEHS).

A team of researchers headed by Geyh had initially surveyed workers at the World Trade Center disaster site in October ("Danger in the Dust," Special Edition 2001). Their findings convinced the NIEHS to support a long-term study. Early analysis of the data has shown, for instance, that workers were exposed to air containing 1,600 to 1,800 micrograms of particulate matter per cubic meter. OSHA considers 10 micrograms per cubic meter to be the maximum safe level - and that's when all particles are benign.

Geyh, an assistant scientist, Environmental Health Sciences, says that researchers are continuing to analyze the composition of the particles they collected at the site in October. So far, the samples have not revealed any detectable levels of crystalline silicates, which can lead to respiratory diseases. And early asbestos findings have also been potentially reassuring: The numbers of asbestos fibers captured by the researchers' filters were consistently low, and few asbestos fibers detected were longer than 5 microns in length. (OSHA only concerns itself with fibers 5 microns or longer.)

"Even if you believe these short fibers are hazardous," says Patrick Breysse, PhD, a professor of Environmental Health Sciences, "our total fiber counts were still 10 times lower than the threshold danger level. Still, our conclusions must be carefully wrought when reporting on a politically charged issue such as asbestos."

The School researchers have remained in contact with the workers studied in October, and are now assembling a follow-up cohort. This long-term study will also include additional clean-up workers newly identified by workers' unions.
- RG


Worried after two of their own died as a result of the fall anthrax attacks, U.S. postal workers turned last fall to Lynn Goldman and Cliff Mitchell at the School for guidance on how to protect themselves against anthrax.

More recently, the postal workers have sought Goldman and Mitchell's advice on the U.S. Postal Service remedy for bioterrorism: irradiating the mail to kill anthrax spores.

American Postal Workers Union members wanted information on general radiation safety and had other questions about the risks involved with the irradiation process, according to Mitchell, an assistant professor of Environmental Health Sciences. "The treatment and what we're doing to the mail will itself create potential new hazards," says Mitchell, MD, MS, MPH '91. Irradiating mail that contains plastics generates "irritating and toxic compounds," according to Mitchell.

Postal workers are worried about the effects of letters irradiated to the point of crispiness.

Irradiated letters have been described as "crispy" and "lightly toasted," while plastic materials have melted. But the process has had more serious effects.

Postal workers have complained of nausea, rashes, headaches, burning eyes, and other conditions after opening bags of the irradiated mail headed for government offices in Washington D.C. Opening the bags in ventilated tents and letting the mail "off gas" for two days appears to have reduced the complaints, according to news reports.

However, the postal worker's union wants more information to ensure the occupational safety of its workers in the new era of bioterrorism. Goldman, professor of Environmental Health Sciences, and Mitchell say that research, supported by grants and other funding, is needed before science can provide definitive answers. Studies need to be done on the effects of the extended antibiotic prophylactic treatments that many postal workers have followed, and new training is needed for mail handlers.

"We're realizing people who work with mail now need new skills and knowledge that they've never needed before," says Goldman, MD, MPH '81. Mail handlers need to know how to identify and "triage" potential hazards in order to respond appropriately. - BWS

In This Issue of Johns Hopkins Public Health Magazine:

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