Office workers, rescuers and others directly exposed to the Sept. 11, 2001, World Trade Center attacks reported new cases of asthma and symptoms of post-traumatic stress five to six years later, according to a study in the Aug. 5 issue of the Journal of the American Medical Association. Exposure to dust clouds, especially among rescuers who worked atop the pile of rubble, increased the likelihood of developing asthma.
The data come from the World Trade Center Health Registry, which tracks 71,437 of the approximately 409,000 adults who personally witnessed the attacks. A total of 46,322 people in four categories — rescue workers, lower Manhattan residents, office workers and passers-by — responded to surveys in 2006 and 2007 about their health.
Slightly more than 10 percent of respondents had developed asthma; 39 percent of those reported intense dust cloud exposure.
The prevalence of post-traumatic stress symptoms, which indicate probable post-traumatic stress disorder, has increased from 14.3 percent, when the researchers first interviewed the subjects in 2003 and 2004, to 19 percent in this new wave of surveys. Factors that increased the likelihood of post-traumatic stress included witnessing people jumping from the towers, being injured and knowing someone who died in the attack. Researchers asked the subjects about symptoms such as flashbacks and emotional numbness.
“There is some evidence, from other studies on veterans, that sometimes people develop PTS symptoms some years later after their trauma,” said the study’s co-author, Robert M. Brackbill of the Centers for Disease Control and Prevention. “We may be seeing that in this same population.” Researchers used this data to estimate that 25,500 adults have post-attack asthma and 61,000 have symptoms of post-traumatic stress.
The third wave of health surveys will go out next year, Brackbill said.