Exposure and Human Health Evaluation of Airborne Pollution from the World Trade Center Disaster
In the days following the September 11, 2001, terrorist attack on New York City's World Trade Center (WTC) towers, many Federal agencies, including the U.S. Environmental Protection Agency (EPA), were called upon to bring their technical and scientific expertise to the national emergency. Several EPA offices, including the Office of Research and Development (ORD), quickly became involved with the Agency's response. This project entails an exposure and human health risk assessment of the impact of air emissions from the collapse of the World Trade Center Towers. ORD's National Center for Environmental Assessment (NCEA) are conducting this assessment at the request of EPA's Region II, which includes the New York City metropolitan area in both New York and New Jersey. The assessment relies primarily on the results of ambient air samples from monitors at various sites in Lower Manhattan and surrounding areas. These monitoring activities were undertaken by Federal, State and local agencies that have made their analytical results available to EPA for analysis. Most of the monitors were placed following the disaster with the intent of surrounding the World Trade Center site at different distances. Some monitors for particulate matter, operated by New York State, existed prior to the disaster. In addition, this report provides a limited discussion of the results of both indoor and outdoor dust samples and the results of some indoor air samples.
The project focuses on: particulate matter (PM), metals (lead, chromium and nickel compounds), polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAHs), dioxin-like compounds, asbestos, silica, synthetic vitreous fibers (SVFs) and volatile organic compounds (VOCs). These substances are included because monitoring indicates that they correlate to the disaster site in both time and space. The assessment is limited to an evaluation of the inhalation pathway, although dust ingestion and dermal contact may also have led to exposures of concern within and near Ground Zero. Trends present in the air monitoring data, associated with location, time, and concentrations, are assessed. These concentrations are related to common health risk benchmarks, such as a reference concentration, RfC, or an air quality index, AQI. There will also be some limited screening assessments associated with assessing cancer and non-cancer risk.
Exposure and Human Health Evaluation: The results of this assessment were released for public review and comment in December of 2002. An external review panel provided the Agency with comments in 2003. The project was completed during 2006 with the submission of a manuscript for peer review journal publication. As of July 2007, a decision has not been reached by the journal to publish the manuscript or not.