According to the Beth Israel Medical Center study, published in the February issue of the Journal of Occupational and Environmental Medicine, officers who arrived at the World Trade Center before the two towers collapsed were most likely to show abnormalities in lung function tests.
After 9/11, Beth Israel researchers offered respiratory health assessments to New York Police Department officers. Respiratory symptoms developed in 77.5 percent of officers studied. Two months later, the symptoms, most often a cough, were gone in 75 percent of the affected officers. But the other 25 percent suffered from continued symptoms, which had gotten worse for some.
Only a few of the officers studied who developed respiratory symptoms showed abnormalities during physical examinations, including x-rays. But when given a lung function test called spirometry, almost 30 percent had abnormal results, although most of those abnormalities were mild.