World Trade Center Disaster and the Health of Workers: Five-Year Assessment of a Unique Medical Screening Program [open pdf - 524KB]
"WTC responders had exposure-related increases in respiratory symptoms and pulmonary function test abnormalities that persisted up to 2.5 years after the attacks. Long-term medical monitoring is required to track persistence of these abnormalities and identify late effects, including possible malignancies. Lessons learned should guide future responses to civil disasters."
Environmental health Perspectives: http://www.ehponline.org/
Environmental Health Perspectives (December 2006), 114:12, 1853-1858