NEW YORK (AP) -- Rescue workers and firefighters contracted a serious lung-scarring disease called sarcoidosis at a much higher rate after the Sept. 11 attacks, said a study that is the first to link the disease to exposure to toxic dust at New York's ground zero.

The study, published by nine doctors including the medical officer monitoring city firefighters, Dr. David Prezant, found that firefighters and rescue workers contracted sarcoidosis in the year after Sept. 11, 2001, at a rate more than five times higher than the years before the attacks.

Unlike previous studies that have linked exposure to the toxic dust cloud that enveloped lower Manhattan after the World Trade Center's collapse to many different respiratory illnesses, this study zeros in on one disease.

Sarcoidosis, which can be life-threatening, causes an inflammation in the lungs that deposits tiny cells in the organs, leaving scar tissues that damage them. Several rescue workers and others exposed to trade center dust have claimed they contracted the disease from their work at ground zero.

The study compared the rates of contracting sarcoidosis among fire department employees for 15 years before Sept. 11 and for five years after it. It said firefighters who showed symptoms of the disease on chest X-rays underwent more intensive exams.

After the trade center attack, 26 firefighters were diagnosed with sarcoidosis, the study found. Thirteen were diagnosed in the first year after the attacks, which represents a rate of 86 per 100,000. In the 15 years before the attack, the rate of sarcoidosis was 15 per 100,0000, the study found.

None of the 26 rescue workers, who are in their 30s and 40s, has died of the disease, and about 10 have improved or recovered since their diagnoses, the study found. Two of the firefighters were former smokers, the study found.

Dr. Jacqueline Moline, who directs the largest monitoring program for ground zero workers, which has screened more than 20,000 people at Mount Sinai Medical Center, said several patients in her program have been diagnosed with sarcoidosis.

Mount Sinai plans to publish its own research in the next few months on the rate associated with ground zero work. Last fall, it published a study concluding that 70 percent of ground zero workers suffered from different respiratory illnesses after the attacks.

"We're all looking to see various diseases that might develop as a result of 9/11 exposure," Moline said. "We have to be vigilant."

The study was published this week in the May issue of CHEST Physician, a journal published by the American College of Chest Physicians.