Oral and Dermal Bioavailability Studies of Polycyclic Aromatic Hydrocarbons from Soils Containing Weathered Fragments of Clay Shooting Targets.

The relative oral bioavailability and dermal absorption of chemical substances from environmental media are key factors that are needed to accurately estimate site-specific risks and manage human exposures. This study evaluated the relative oral bioavailability and dermal absorption of several polycyclic aromatic hydrocarbons (PAHs) found in soils collected from two formerly used Department of Defense sites impacted by weathered fragments of clay shooting targets. Concentrations of individual carcinogenic PAHs in the ≤250 μm fraction of soil ranged from approximately 0.

Risk assessment implications of site-specific oral relative bioavailability factors and dermal absorption fractions for polycyclic aromatic hydrocarbons in surface soils impacted by clay skeet target fragments.

Risk assessment conclusions for a site may differ when using site-specific versus default values for the relative bioavailability factor (RBAF) and dermal absorption fraction (ABS.d), because these inputs affect both surface soil screening levels and risk/hazard estimates. Indeed, our case study demonstrates that different conclusions may be reached as to regulatory need for remedial action to protect human health when evaluating soil sampling data for seven carcinogenic polycyclic aromatic hydrocarbons (PAHs) using site-specific versus default TCEQ and USEPA residential soil screening levels.

Quantitative determination of hydroxy polycylic aromatic hydrocarbons as a biomarker of exposure to carcinogenic polycyclic aromatic hydrocarbons.

A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) method was developed for quantitative analysis of hydroxy polycyclic aromatic hydrocarbons (OH-PAHs). Four hydroxy metabolites of known and suspected carcinogenic PAHs (benzo[a]pyrene (B[a]P), benz[a]anthracene (B[a]A), and chrysene (CRY)) were selected as suitable biomarkers of PAH exposure and associated risks to human health. The analytical method included enzymatic deconjugation, liquid - liquid extraction, followed by derivatization with methyl-N-(trimethylsilyl) trifluoroacetamide and instrumental analysis.