It takes less than a year for doctors to treat most patients with Hodgkin's disease. Ryan McCormick has been battling the lymphatic system cancer for four.

"Something's not right, either with me, the disease or the medicine," says McCormick, 32, of Verona, N.J.

McCormick was working as a paramedic at the emergency medical services command post at Ground Zero two days after the Sept. 11 terrorist attack. He spent 16 hours on the job.

He suspects his medical condition was at least aggravated, if not caused, by his exposure to toxins at the World Trade Center disaster site.

"There's no way you can tell us what was floating around down there was at all healthy," McCormick said. "There's no way. You're not supposed to see the air floating in front of you. You're not supposed to put on a respirator and have the canister clog immediately."

McCormick's claim echoes throughout New York and beyond. Tens of thousands of first responders who worked for days, weeks or months at the World Trade Center site are worried about their health.

They were exposed to a stupendous mix of compounds, according to clinical studies: soot produced by burning jet fuel; clouds containing cement dust, glass fibers, asbestos, lead, hydrochloric acid, polychlorinated biphenyls (PCBs), and pesticides; diesel exhaust from first-response vehicles; and smoke produced by both underground and above-ground fires that were not extinguished for three months.

About 71,000 people have enrolled in a World Trade Center Health Registry run by the New York City Department of Health and Mental Hygiene and financed by the federal government. They are being surveyed to assess the health status of people who were not working at the site as first responders. The results will not be known until next year.

"We really don't have a lot of good information about that non-responder population," Dr. John Howard, director of NIOSH, said Friday. "So I think it's important that the Congress always keep it on their agenda, always ask people like us, `What do you see? What's your data? Advise us.' It's an important public policy issue."

"Amazingly, every single state and 431 of the 435 congressional districts nationwide have someone in the World Trade Center Registry in New York City. This is a health emergency on a national scale, and it requires a strong federal response," Rep. Carolyn Maloney, D-N.Y., said Thursday.