In the decade since 9/11 terrorist attacks, hundreds of rescue and recovery workers on the scene that day have developed debilitating respiratory conditions they say were caused by exposure to environmental conditions such as jet fuel combustion and smoldering debris fire.

Now researchers may have found a link between post-traumatic stress disorder (PTSD) and the illnesses afflicting many of those people.

Using data from more than 20,000 responders, a research team found a “striking correlation” between PTSD and respiratory symptoms, as well as evidence that PTSD might play a significant role in the exposure-symptom relationship.

“The results are indicative that PTSD appears to have a major and complex role in relation to respiratory illnesses in this patient population,” said Stony Brook University School of Medicine’s Evelyn Bromet, Ph.D., in a statement. “Our findings mirror research results found in several veterans’ populations … Mental and physical health are integrally linked.”

Both Dr. Bromet and Benjamin J. Luft, M.D., Medical Director of Stony Brook’s World Trade Center Health Program, say while more study is needed, their study underscores the importance of performing mental health screenings on 9/11 responders in addition to traditional physical health exams.

“[The findings] reinforce our view … that the illnesses suffered by 9/11 responders are a compilation of problems that often present as an entire syndrome of diseases and conditions,” said Dr. Luft.

In Dec. 2010, Congress passed the James Zadroga 9/11 Health and Compensation Act to provide free medical care and compensation to first responders. According to reports, some first responders have yet to receive these benefits.