September 10, 2002, Section A, Page 1Buy Reprints View on timesmachine TimesMachine is an exclusive benefit for home delivery and digital subscribers.
As many as 500 New York City firefighters may have to retire early as a result of ''respiratory disability,'' chronic breathing problems caused by their exposure to dense clouds of dust, smoke and fumes at the World Trade Center, health officials said yesterday.
The potential departure of the firefighters comes as the department is still struggling to deal with the loss of 341 firefighters and 2 paramedics, who were among the 2,801 people killed in the collapse of the twin towers after the attack on Sept. 11.
As of Aug. 28, 358 firefighters and 5 emergency medical workers were still on medical leave or light duty because of respiratory disorders that began after they worked at the site. Symptoms include persistent cough, wheezing, shortness of breath and other asthma-like symptoms, sinus inflammation and heartburn.
David J. Prezant, deputy chief medical officer of the New York Fire Department, said doctors did not know exactly what the affected workers had been exposed to, or whether they would get better or worse. Many, he said, worried about whether they would develop more serious lung diseases or cancer.
Their current problems are thought to have been caused by the inhalation and swallowing of fine particles created by the fires and building collapse. Workers who had the heaviest exposure -- those who were there when the buildings collapsed and in the first few days and weeks after -- had the highest incidence of respiratory trouble. Very few firefighters used respirators or other types of breathing protection in the early days after the attack, when the air was at its worst.
In addition to the 363 firefighters and rescue workers with respiratory disability, 213 others were on leave with emotional stress resulting from their work at the site and from their grief over the deaths of so many friends and co-workers. The number of stress-related incidents observed among the workers during the 11 months after the attack was 17 times the number that occurred in 11 months before the attack.
Reports on the firefighters' injuries and illnesses are to be published tomorrow by the Centers for Disease Control and Prevention, and another, to be published on Thursday in the New England Journal of Medicine, has already been published on the journal's Web site, www.nejm.com.
Over all, the surviving firefighters have fared both better and worse than doctors expected. Considering that nearly all of the city's more than 11,000 firefighters worked at the site, and that 90 percent developed a cough, the proportion with chronic problems is relatively small.
''Some might have thought the percentage would be higher,'' said Dr. Prezant, who is also a professor at Albert Einstein College of Medicine and an author of both reports.
In the firefighters who do have lingering symptoms, however, the problems have been more severe and persistent than doctors would have expected, Dr. Prezant said. In the past, among firefighters who had respiratory problems from smoke inhalation, 90 percent recovered. But among the 332 firefighters who had a severe case of ''World Trade Center cough,'' only 48 percent have fully recovered and returned to work. Severe cases were defined as those needing four or more consecutive weeks of medical leave.
Dr. Prezant said the reason that the symptoms were so severe was probably that the concentration of particles was very high, and the exposures prolonged and repeated.
''We're never going to know the full scale of what the firefighters were exposed to on that day,'' Dr. Prezant said. He said that air quality testing did not begin until several days after the attack. But he said everyone at the site was clearly exposed to ''a massive dust cloud'' full of tiny particles that could be inhaled into the airways and lungs.
''Even if that respirable airborne particulate matter does not include a single chemical, it is incredibly toxic at that level of exposure,'' Dr. Prezant said, adding that there was a great deal of evidence that exposure to such material can cause increased rates of chronic lung disease like emphysema and heart disease.
The very finest particles can make their way into the depths of the lung and persist there for a long time, he said. Some particles, like asbestos fibers, stay in the lung forever. Other particles can be digested and removed. But in some cases, Dr. Prezant said, ''the enzymes used to digest them can lead to lung inflammation and destruction, and that's why, in some people, the healing response can be part of the illness.''
Dr. Prezant said that one of the most important findings of the study was that many of the firefighters with persistent cough and other respiratory problems also had heartburn, or gastroesophageal reflux, a condition in which stomach acid backs up into the esophagus and throat. He said swallowing the particles may irritate the stomach and esophagus, and that in the firefighters, the condition may have been aggravated by stress, long hours and irregular meal times.
He said doctors had not realized before these cases that heavy inhalation or swallowing of particulates could bring on reflux. The reflux may cause the respiratory problems or make them worse, he said.
''This is critically important for physicians to know,'' he said, because the cough does not improve unless the reflux is treated.
The report by the disease centers also includes a summary of a survey, taken 6 weeks after the attack, of people who lived near the trade center. About 75 percent were initially evacuated from their homes. Many reported that they had had health problems: 66 percent had nose or throat irritations; 50 percent had eye irritations or infections; 47 percent had coughs. About 39 percent had signs of post-traumatic stress.
People who worked in the area also had health concerns and stress-related problems. Sherry Baron, an official with the National Institute for Occupational Safety and Health, said that at the time, health officials did not realize how deeply those people were affected. ''Perhaps one of the lessons we can learn,'' Dr. Baron said, ''is to have adequate outreach programs and other kinds of services ready and available to a much wider group of people than we might have thought about at the time.''
The new reports also address questions about the firefighters' use -- or failure to use -- respirators. In the first hours after the attack, most of the thousands of rescuers and workers converging on the site rushed into the swirling clouds of dust and smoke without much regard for their lungs, the reports say, based on surveys of the workers.
Among those who had severe cases of the cough, 93 percent said they used respirators ''rarely or not at all'' on the first day and only a little more in subsequent days.
Reviews of the emergency response concluded that this was partly the result of the urgency of the task and also because New York City officials and federal officials simply did not have the right gear on hand.
A week elapsed before most workers were wearing the device that federal worker-health officials decided was best suited to the conditions: a half-face respirator, a rubbery mask that seals around the nose and mouth and can be fitted with different filters.
During their first hours at the site, firefighters often had inappropriate protection, Dr. Baron and other health officials found. Most either had no lung protection or used paper masks. Others relied on the heavy backpack-style pressurized breathing systems they use to fight conventional fires. But these were cumbersome, and provided air for only about 8 to 15 minutes, Dr. Prezant said.
At the trade center, Dr. Baron said, ''It took just about a week before the normal systems and supplies kicked into place.''
''The lesson here is how to move that process up three or four days,'' she said.
Dr. Prezant said that ironworkers at the site also had increased rates of respiratory problems, but were being studied by other researchers who had not yet published their findings.