NEW YORK (AP) — Rescue workers and firefighters contracted a serious lung-scarring disease called sarcoidosis at a much higher rate after the September 11 attacks than before, said a study that is the first to link the disease to exposure to toxic dust at 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 September 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 September 11 and for five years after it. It said firefighters who showed symptoms of the disease on chest X-rays underwent more intensive exams.