An Evaluation of Carcinogenic Risk Assessment from Exposure to Background PAH Concentrations in Soil

摘要

In many urban areas, background concentrations of polynuclear aromatic hydrocarbon (PAH) compounds have been found at levels that exceed the remediation goals established by regulatory agencies for carcinogenic PAHs. Recent studies sponsored by the Electric Power Research Institute (EPRI) and the United States Geological Survey (USGS) in cooperation with the Chicago Department of Environment have measured Chicago area concentrations of PAH compounds in surface soil. The Illinois Environmental Protection Agency (IEPA) has accepted the validity of these studies and established the 95th percentile PAH levels in soil as the background concentrations for urbanized areas including the Chicago Metropolitan Area and for areas in Illinois outside the metropolitan areas. These background levels are used for setting remedial objectives at Illinois sites with PAH contamination. This paper presents an evaluation of a human health risk assessment that was completed to study several common exposure scenarios assuming PAH concentrations in soil were at "Chicago background" levels. The risk characterization results of the exposure to carcinogenic PAHs in residential, industrial/ commercial, landscape worker and recreational park use settings are presented. The carcinogenic risk associated with background PAHs in soil provides useful information in setting remediation goals and in identifying and understanding the factors that contribute to site-specific risk.