Lung Function of 9/11 Rescuers Fell, Study Finds

Rescue workers exposed to thick clouds of dust after the attack on the World Trade Center had large drops in lung function lasting at least seven years, a study of nearly 13,000 workers has found.

The study is the first to document long-term harm in a large group of firefighters and emergency medical workers who worked at ground zero between Sept. 11 and Sept. 24, 2001. All had had previous tests of lung function, so there were baseline readings with which the measurements after the attack could be compared.

The dust exposure left “a substantial proportion of workers with abnormal lung function,” the researchers report in an article to be published on Thursdayin The New England Journal of Medicine.

“The fact that this decline is persistent demonstrates that there is a need for continued monitoring and aggressive treatment,” Dr. David J. Prezant, an author of the study and the chief medical officer in the Office of Medical Affairs at the New York City Fire Department, said in an interview. “It is real.”

The study included 91.6 percent of the nearly 14,000 firefighters and Emergency Medical Service staff members who worked at ground zero in the first two weeks after the attack. The results are based on lung function tests performed every 12 to 18 months from March 2000 until September 2008.

On average, the rescue workers lost about 10 percent of their lung function in the year after the attack, with little or no recovery over the next six years, Dr. Prezant said. Firefighters who arrived on the morning of Sept. 11 had the largest declines in the first year, because they were more likely to be caught in the worst of the dust cloud that erupted when the two towers collapsed after two jetliners were flown into them. Firefighters over all had greater declines than medical workers.

Dr. Prezant said the effects on how people actually felt varied, depending on how strong their lungs were to begin with and whether they developed other ailments from their exposure. A healthy, vigorous person might not even be aware of a 10 percent drop in lung function, though it may make a difference under extreme conditions in a physically demanding job like firefighting.

Of all the firefighters and emergency workers who were exposed, 30 percent to 40 percent, about 5,000, were found to have persistent symptoms, like cough, wheeze, sore throat, shortness of breath or sinus drip, Dr. Prezant said. Nearly 1,000 from that group have qualified for “permanent respiratory disability” because of asthma or chronic bronchitis. Medicines can ease their symptoms but not cure them, and are usually needed long term. Asthma can end a firefighter’s career, because smoke often brings on attacks.

Previous studies of firefighters after fires, including chemical fires, found that they also had declines in lung function, but the drops were smaller and temporary, with full recovery in a few weeks.

“This was not a regular fire,” Dr. Prezant said. “There were thousands of gallons of burning jet fuel and an immense, dense particulate matter cloud that enveloped these workers for days.”

The cloud contained pulverized glass and cement, insulation fibers, asbestos and numerous toxic chemicals.

“It caused acute inflammation of the airways and the lungs,” Dr. Prezant said. “That inflammatory impact has been persistent.”

An expert not involved with the study, Dr. Byron Thomashow, medical director of the Center for Chest Disease and Respiratory Failure at NewYork-Presbyterian/Columbia hospital, said: “The drop-off in lung function initially is really quite significant and doesn’t get better. That’s not what we’ve generally come to expect in people with fire and smoke exposure. They usually recover.”

A 2009 report by the city’s World Trade Center Medical Working Group also reported increases in asthma among heavily exposed people after Sept. 11, with 17,400 to 40,000 new cases in adults.

Over all, 13 percent of the firefighters and 22 percent of the emergency medical workers have lung function that is below normal for their age. (Dr. Prezant said the firefighters had fared better than medical workers because the rigorous physical tests that firefighters must pass to qualify for their jobs mean they generally start out with better lung function.)

All the exposed workers have impaired lung function, Dr. Prezant said. Smokers were affected slightly more than nonsmokers.

“This persistent drop has occurred in everyone,” he said. “Even the group not severe enough to have an impact on their lives today, they have lower pulmonary function than when they started, and that means they are at risk.

“The extent of that risk for future developments we don’t know, because we’ve never had this type of exposure before.”

Lung function normally declines with age, but the average drops in the rescue workers one year after the attack were equal to 10 to 12 years of aging.

Even in firefighters who now feel well, the drops in lung function could later affect their ability to exert themselves, especially in smoky conditions, Dr. Prezant said. Impaired lung function can also make it difficult for people to recover from surgery or respiratory illnesses like pneumonia.

Thousands of workers at ground zero have sued the city over health problems, and lawyers representing them say the new findings bolster their case.

Andrew Carboy, a lawyer with a firm representing 690 plaintiffs, said: “These declines are persistent, without recovery, leaving abnormal lung function. That’s been our contention, and now the city itself is acknowledging it.”

Another lawyer, Marc J. Bern, whose firm represents about 9,000 plaintiffs, said the study proved that the lung problems were permanent.

But the article calls the problems persistent, and Dr. Prezant said: “I don’t ever want to use the word permanent. There may be subgroups that can still respond to therapy.”

Meanwhile, the lawsuits are in limbo. Last month the two sides reached a settlement in which up to $657.5 million would be used to compensate about 10,000 plaintiffs according to their degree of exposure and illness. But a judge rejected the settlement, saying it would pay the plaintiffs too little and their lawyers too much. A hearing is set for Monday.

“This article is critical,” Mr. Bern said, “as it further demonstrates the need for a resolution to this lawsuit and a quick resolution, as opposed to a delay in getting the needed funds to these workers.”

A government Web site lists roughly 250 scientific articles about the physical and mental effects of the attacks on rescue workers and other people.