There were a large number of rescue and recovery workers who responded to the September 11 2001 disaster at the WTC. The exposure to the dust and debris has had a toll on their health. According to the World Trade Center Health Registry, 3.6% of the 25,000 rescue and recovery workers have contracted asthma after working there. This is 12 times more than the normal rate. The paper was published today in the journal Environmental Health Perspectives and is available online at www.ehponline.org.
The rescue and recovery workers are a subset of the 71,000 people enrolled in the registry. The survey, conducted in 2003 and 2004, found that arriving soon after the buildings collapsed, or working on the WTC pile over a long period, increased the workers risk of developing asthma. Workers who arrived on September 11, 2001, and worked more than 90 days reported the highest rate of new asthma (7%).
Though respirator use increased as the clean-up progressed, many workers did not wear respiratory protection at the outset. Certain respirators can reduce exposure to hazardous dust when used correctly, but the survey could not distinguish among different types of masks or respirators, nor could it gauge correct usage.
Workers who wore them on September 11th and September 12th reported newly-diagnosed asthma at lower rates (4.0% and 2.9%, respectively) than those who did not (6.3% and 4.5%). The longer the period of not wearing masks or respirators, the greater the risk, the survey found. Workers who went months without respiratory protection reported two to three times more asthma incidence than those who wore respirators from the outset. Though respirators were shown to be protective, all worker groups, including those who reported wearing masks, had elevated levels of newly reported asthma.