Three weeks after the disaster, researchers screened 362 firefighters (319 exposed and 43 unexposed) for length of time and work activities at the disaster site, respirator use, and respiratory symptoms. Pre-WTC and post-WTC exposure spirometry measurements were available for 289 exposed firefighters and 34 unexposed firefighters. A control group of 735 unexposed firefighters with two pre-WTC spirograms was used as a comparison.
Results showed that firefighters present in the first 48 hours reported greater respiratory symptoms than those present on days three to seven, and greater lung function decline than the control group. Firefighters working for seven or more days in the first two weeks at the WTC site had a 32 percent increase in respiratory symptoms than firefighters working less than seven days. Compared to unexposed firefighters, exposed firefighters had elevated symptoms, such as eye irritation, sore throat, daily cough, and nasal congestion. The study appears in the April issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians.
In the same issue of CHEST, New York and Los Angeles researchers examined 96 ironworkers who spent at least three days at the disaster site underwent a medical and exposure history, physical exam focusing on respiratory systems, spirometry and chest radiographs. Seventy-five ironworkers underwent additional respiratory screening using forced oscillation (FO).
Results indicated that 77 percent of the ironworkers had one or more respiratory complaints, including cough, shortness of breath, chest tightness and wheezing, and that early exposure to the WTC collapse significantly influenced the prevalence of cough. No statistical significance was found between respiratory symptoms and duration of exposure or smoking status. Researchers also found that spirometry underestimated respiratory symptoms as compared to FO.