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

摘要

In many urban areas, background concentrations of polynuclear aromatic hydrocarbonrn(PAH) compounds have been found at levels that exceed the remediation goalsrnestablished by regulatory agencies for carcinogenic PAHs. Recent studies sponsored byrnthe Electric Power Research Institute (EPRI) and the United States Geological Surveyrn(USGS) in cooperation with the Chicago Department of Environment have measuredrnChicago area concentrations of PAH compounds in surface soil. The IllinoisrnEnvironmental Protection Agency (IEPA) has accepted the validity of these studies andrnestablished the 95th percentile PAH levels in soil as the background concentrations forrnurbanized areas including the Chicago Metropolitan Area and for areas in Illinois outsidernthe metropolitan areas. These background levels are used for setting remedial objectivesrnat Illinois sites with PAH contamination. This paper presents an evaluation of a humanrnhealth risk assessment that was completed to study several common exposure scenariosrnassuming PAH concentrations in soil were at “Chicago background” levels. The riskrncharacterization results of the exposure to carcinogenic PAHs in residential, industrial/rncommercial, landscape worker and recreational park use settings are presented. Therncarcinogenic risk associated with background PAHs in soil provides useful information inrnsetting remediation goals and in identifying and understanding the factors that contributernto site-specific risk.