Evaluation of potential human exposures to airborne particulate matter following the collapse of the World Trade Center Towers.

The World Trade Center attack on September 11, 2001 resulted in dispersal of numerous potentially toxic materials in the dust and smoke cloud that enveloped lower Manhattan and extended over other New York City areas. This chapter illustrates approaches used, under challenging circumstances and time constraints, to evaluate human exposures of the general population to WTC-derived airborne particulate matter and potential associated human health impacts, based on integrating information derived from (a) analyses of composition and toxicity of deposited dust; (b) data from ambient air monitoring at Ground Zero, and at sites in lower Manhattan and elsewhere in the metropolitan area; (c) atmospheric dispersion modeling of the WTC plume movement/dispersal; (d) comparison of concentrations against peak urban pollutant levels and against health benchmark values judged to be indicative of risk for adverse effects due to short-term and/or prolonged particulate exposures.