Dose-Response Analysis of Ingested Benzo[a]pyrene
This report represents the first part of the Office of Health and Environmental Assessment's dose-response analysis of polycyclic aromatic hydrocarbons (PAHs). Because of the tremendous amount of information bearing on approaches that can be developed to estimate risks from exposures to PAHs, the task is divided into three steps beginning with an analysis of benzo[a]pyrene (BAP), one of the PAHs. The steps are: (1) determining the oral potency slope for benzo[a]pyrene (B[a]P) (2) determining the inhalation potency slope for B[a]P, and (3) determining the potency slopes for other PAHs using a relative potency approach. The focus of this report is on estimating the carcinogenic potency slope of B[a]P by ingestion. The potency slope is used to provide an upper-bound estimate for risk from ingesting low doses of B[a]P. t should be noted that only information relevant to analyzing dose-response relationships by ingestion is analyzed in this report. he determination of potency slopes for B[a]P is chosen as the first two steps because there is more information on B[a]P than other PAHs that are found in environmental media. urthermore, few PAHs have even minimal information for performing dose response analysis of oral or inhalation routes of exposure. owever, results from skin painting experiments on PAHs where B[a]P is used as positivecontrols are available. he potential of using B[a]P as a reference point in deriving oral and inhalation potency slopes for other PAHs can be developed. he validity of calculating relative potency between two compounds based on data from one route of exposure and then extrapolated to another route of exposure needs verification.