Polycyclic aromatic compounds in indoor dust, skin wipes, and urine of oilfield workers: Human exposure pathways and associations with oxidative stress.

Polycyclic aromatic compounds (PACs) are common constituents of crude oil and its refined products, and they can be released into the ambient environment during oil exploitation activities, potentially adversely affecting environmental and human health. Herein, forehead (n=76) and hand wipes (n=76) and urine samples (n=102) from oilfield workers as well as indoor dust samples (n=19) (not individually paired with skin wipe and urine samples) in the oil exploitation area were collected, and 45 PACs and 15 PAC metabolites (mPACs) in these matrices were comparably determined. The median concentrations of ∑PACs in forehead and hand wipes and ∑mPACs in urine were 1.2-4.3 times higher in frontline workers than those in office administrators. Significant differences in PAC profiles were observed between different matrices, with relatively hydrophilic PACs being least in indoor dust, intermediate in hand wipes, and most abundant in forehead wipes. Furthermore, five PACs in forehead and hand wipes and their corresponding mPACs in urine exhibited significant positive correlations. Exposure assessment indicated that dermal uptake of low molecular weight (LMW) PACs contributed dominantly to internal exposure (20.2%-67.4%) compared to dust ingestion (< 2%). The quantile g-computation model revealed that hydroxynaphthalene (∑OH-Nap), 1-OH-pyrene, and 2-OH-dibenzofuran were the major contributors to the mPAC mixture's effect on lipid peroxidation, and dermal exposure may represent a potential pathway by which LMW PACs, particularly Nap, were associated with lipid peroxidation based on multiple linear regression. This study enhances understanding of less well-studied PAC exposure and supports oil exploitation contamination control.