Ingestion bioaccessibility of indoor dust-bound PAHs: Inclusion of a sorption sink to simulate passive transfer across the small intestine

In this study, we investigated the levels of 12 priority polycyclic aromatic hydrocarbons (PAH(12)) pollutants, bioaccessible PAH(12), and sorption sink for PAH(12) by a silicone sheet of indoor dust samples, which were collected from teachers' offices (n = 17), students' offices (n = 17), laboratory (n = 11), and experimental center (n = 9), using an in vitro digestive model. In PAH(12), bioaccessible PAH(12), and sorption sink PAH(12), benzo[b]fluoranthene (BbF), phenanthrenes (Phe), and fluoranthene (FLA) were labeled respectively the most significant PAHs (6.61 +/- 4.42 mu g/g, 0.16 +/- 0.11 mu g/g, and 0.08 +/- 0.06 mu g/g) after indoor dust ingestion, whereas the proportions of anthracene (Ant), benzo(g,h,i)perylene (BghiP), and BghiP (0.34 +/- 0.17, 0.03 +/- 0.03 and 0.01 +/- 0.01 mu g/g) were low. Based on benzo[a]pyrene-equivalent carcinogenic concentrations, the mean daily exposure of bioaccessible PAH(12) and sorption sink for PAH(12) by indoor dust ingestion was 4.07 x 10(-3) +/- 1.73 x 10(-3) and 3.23 x 10(-3) +/- 1.36 x 10(-3) mu g/day in the experimental center; 4.01 x 10(-3) +/- 2.05 x 10(-3) and 1.46 x 10(-3) +/- 6.72 x 10(-4) mu g/day in students' offices; 8.25 x 10(-4) +/- 2.33 x 10(-4) and 5.15 x 10(-4) +/- 1.37 x 10(-4) mu g/day in laboratory; and 7.05 x 10(-4) +/- 4.12 x 10(-5) and 2.82 x 10(-4) +/- 4.36 x 10(-5) mu g/day in teachers' offices, respectively. Our results indicated that the passive transfer fraction of PAH12 (44.07%-67.36% in this case) is therefore large and needs to be considered in exposure and risk assessments. (c) 2019 Elsevier B.V. All rights reserved.