An Air Emission Risk Assessment for Benzo(a)pyrene and Arsenic from the Mt. Tom Power Plant

Abstract

The Electric Power Research Institute’s Air Emissions Risk Assessment Model (AERAM) was developed to assess the risk of toxic air emissions from coal-fired power plants. AERAM was used to study the cancer risk to the population through inhalation of airborne emissions from the Mount Tom coal-fired power plant. AERAM treats coal fly ash by particle size classes and accounts for enrichment of trace elements as a function of particle size. The stack emissions are used as a source term for atmospheric dispersion calculations using EPA’s ISCLT model to obtain exposures at designated receptor points. Single-hit, multi-stage, and log-probit risk models are available for extrapolation of animal cancer data to establish the carcinogenic risks of the nearby residents. The resulting risks for arsenic and benzo(a)pyrene emissions were found to be very low. The carcinogenic risks determined by sample runs and the key sensitivities of the model options and input are presented.