Comparison of Results Based on Multimedia Modeling of Arsenic Emissions from Secondary Lead Smelters and Coal-Fired Electric Utility Plants. A. B. Vasu, U.S. EPA, OAQPS/AQSSD/REAG (MD-15), Research Triangle Park, NC 27711; G. Rice, U.S. EPA, NCEA (MS-190), Cincinnati, OH 45268; M. G. Dusetzina, U.S. EPA, OAQPS/AQSSD/REAG (MD-15), Research Triangle Park, NC 27711; and B. F. Lyon and S. T. Purucker, Oak Ridge National Lab, 1060 Commerce Park, MS-6480, Oak Ridge, TN 37830
Arsenic compounds, which pose health risks to humans from exposure through inhalation and ingestion, are emitted by many anthropogenic emission sources. Because few measured data exist which examine the fate of these emissions, a series of mathematical models were used to predict the environmental fate and transport of atmospheric arsenic emissions from two anthropogenic emission sources: secondary lead smelters and coal-fired electric utility plants. Total arsenic concentrations in media and biota that result from the arsenic emissions were predicted. Since arsenic compounds may be transported through multiple environmental compartments, both inhalation and non-inhalation routes of human exposure were modeled. The dispersion and deposition of emitted arsenic was estimated using the Industrial Source Complex 3 model (ISC3). Results of the dispersion and deposition modeling were used as inputs to the EPA Indirect Exposure Model 2 (IEM2) and the EPA Human Exposure Model (HEM), the models chosen for analysis of the non-inhalation and inhalation exposure pathways, respectively. The modeling results were used to identify significant exposure pathways, to estimate the magnitude of arsenic concentrations in biota and media, and to compare the impacts of the two emission sources. Critical variables that affect the outcomes have been identified and will be discussed.