Draft document with asbestos data tables, DEP Box 09

NYC 9/11 Public Portal Document

k DRAFT Introduction TRC Environmental Corporation (TRC) performed a human health risk assessment evaluating the potential for adverse health effects associated with exposure to airborne asbestos fibers at levels measured in the emergency response vehicles recovered from the World Trade Center (WTC) site. This human health risk assessment was performed in accordance with the general methods and procedures outlined in applicable guidance documents developed by the U.S. Environmental Protection Agency (EPA) (1989a,b). This assessment is based on the results provided by New York Department of Health, the details of which can be found in the memorandum titled “Environmental Health Considerations of WTC Vehicles ”

Conceptual Model Vehicles that have been recovered from the WTC site have had their interior spaces contaminated with the dust and debris generated during the WTC collapse. The degree to which any individual vehicle was impacted in this manner varies with a number of factors, including, whether or not the windows of the vehicle were broken and whether or not the vehicle was running with ventilation systems on during the collapse. The data set used to estimate risk for normal use of recovered vehicles was collected from emergency and rescue vehicles that were generally situated closer to the WTC during collapse. It was assumed that these vehicles were most damaged and were considered to represent a ‘worst case’ in terms of being impacted by dust and debris.

The risk assessment estimates cancer risk for the population of individuals who are slated to retake possession of recovered vehicles and return these vehicles to normal use. Under normal use the receptor population is assumed to be exposed to airborne asbestos fibers while driving and while periodically cleaning the interior of the vehicle. It is assumed for the purposes of this risk assessment that the vehicles carpet and upholstery serve as a continuous source of asbestos fibers that become airborne during driving and interior cleaning. It is also assumed that the vehicles would be cleaned using methods similar to those employed for the emergency vehicles described above.

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