Biomonitoring of smoke constituents: exposure to 4-aminobiphenyl and 4-aminobiphenyl hemoglobin adduct levels in nonsmokers and smokers

Abstract

Public health authorities worldwide have concluded that exposure to environmental tobacco smoke (ETS) causes diseases, including cancer, in adult nonsmokers. The arylamine, 4-aminobiphenyl (4-ABP), has been identified as a human carcinogen. Some publications have suggested that 4-ABP hemoglobin (4-ABP-Hb) adduct levels in nonsmokers are a result of exposure to ETS, whereas others could not confirm these observations. Toxicokinetic and exposure models proposed in this work are used to estimate the concentration of 4-ABP-Hb adducts resulting from ETS exposure that is based on experimental values for respirable suspended particulates (RSP) concentration. Monte Carlo methods were used to obtain estimates of population distributions of 4-ABP-Hb adduct levels resulting from indoor ETS exposure in homes, workplaces, and hospitality environments. It is found that the mean, median, and 95th percentile 4-ABP-Hb adduct steady-state levels of 0.4–1.4, 0.2–1.0, and 0.97–4.63 pg/g Hb, respectively, are estimated from ETS exposure. These 4-ABP-Hb adduct levels from ETS exposure account for ~1–4% of the median levels reported for nonsmokers, explaining, in part, contradictory literature data on 4-ABP-Hb adduct levels in nonsmokers. No risk assessment of ETS or 4-ABP was conducted in this work, consequently the known health effects of ETS are neither confirmed or challenged and our conclusions are limited to the determination that ETS is not a major source of 4-ABP-Hb adduct levels in non-smokers.