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.
Acknowledgments
The authors express their appreciation to Frank Hsu, Raymond Lau, Edward Sanders, Regina Stabbert, and Anthony Tricker for contributions to this manuscript and to Prof. G. Scherer for sharing additional unpublished “Pilot Study” data to supplement those that were published (CitationTricker et al., 2009). We also thank Prof. P. Dolara for sharing additional data on 4–ABP concentrations in air that did not appear in their publications (CitationLuceri et al., 1993; CitationPalmiotto et al., 2001).
Declaration of interest
Dr. Matthias K. Schorp is a current employee of Philip Morris Products SA, and Dr. Donald E. Leyden was a former employee and consultant of Philip Morris Products SA.
Notes
1 When sufficient data were not available to calculate the standard deviation, it was estimated from error propagation principles