New York ? New York Five months later, the terrorist attack on the World Trade Center is still claiming victims.

Those who are suffering now are the workers and residents who breathe the air around Ground Zero daily. Many of them say that, despite federal government assurances that the air is safe, the dust and toxins released by the collapsing towers have made them sick, disrupting their lives and arousing fears of long-term health problems, such as asthma or lung cancer.

Frank Shane and his dog, Nikie, overlook Ground Zero in this file photo. Many workers in the area are concerned that the air quality caused by the collapsing towers has made them sick.

In several instances, parents of young children have been afraid to send their children back to elementary schools near the trade center site. Residents who returned to dust-laden apartments near Ground Zero have been unsure of how to clean up the mess without endangering their health. And day laborers hired to clean offices have often worked without equipment to protect them from inhaling cancer-causing asbestos or other potentially dangerous substances.

The controversy over air quality in Lower Manhattan and its impact on health will be the subjects of a Senate committee hearing Monday in New York to find out whether local and federal agencies acted properly in the aftermath of the attacks.

Ground Zero symptoms

The symptoms being reported range from persistent, hacking coughs to dizziness and headaches. In some cases, exposure to the pulverized concrete and other microscopic airborne debris from the trade towers is believed to have caused asthma.

Of the 8,000 firefighters who have been tested since Sept. 11, 25 percent are suffering from “World Trade Center cough,” or displaying other symptoms such as shortness of breath and wheezing, according to Fire Department chief medical officer Dr. David Prezant.

Hundreds of firefighters have served notice that they intend to sue the city for negligence, charging that inadequate supplies of respirators resulted in unnecessary exposure to asbestos.

High asbestos levels

Since Sept. 11, 22 EPA air monitors in the vicinity of Ground Zero have recorded 31 instances of asbestos levels in excess of federal standards out of more than 5,500 samples, and only four of those have occurred since Sept. 30, according to spokeswoman Nina Habib Spencer.

Several efforts are under way to track whether greater illness shows up among people who were exposed to the plumes of dust and smoke that billowed through Lower Manhattan for several weeks as the underground fires at the trade center continued to burn.