World Trade Center disaster: Assessment of responder occupations, work locations, and job tasks

Background: To date there have been no comprehensive reports of the work performed by 9/11 World Trade Center responders. Methods: 18,969 responders enrolled in the WTC Medical Monitoring and Treatment Program were used to describe workers' pre-9/11 occupations, WTC work activities and locations from September 11, 2001 to June 2002. Results: The most common pre-9/11 occupation was protective services (47%); other common occupations included construction, telecommunications, transportation, and support services workers. 14% served as volunteers. Almost one-half began work on 9/11 and >80% reported working on or adjacent to the "pile" at Ground Zero. Initially, the most common activity was search and rescue but subsequently, the activities of most responders related to their pre-9/11 occupations. Other major activities included security; personnel support; buildings and grounds cleaning; and telecommunications repair. Conclusions: The spatial, temporal, occupational, and task-related taxonomy reported here will aid the development of a job-exposure matrix, assist in assessment of disease risk, and improve planning and training for responders in future urban disasters.