Comparison of in vitro digestion model with in vivo relative bioavailability of BDE-209 in indoor dust and combination of in vitro digestion/Caco-2 cell model to estimate the daily intake of BDE-209 via indoor dust

There is limited information on the BDE-209 relative bioavailability (RBA) of indoor dust and the absorption of BDE-209 after in vitro digestion was seldom studied. In the present study, BDE-209 RBA in 6 household dust samples measured using an in vivo mouse model was compared to BDE-209 bioaccessibility determined using physiologically based extraction test (PBET) and solubility bioaccessibility research consortium method (SBRC) assays. BDE-209 RBA obtained ranged from 45.9 ± 16.1 to 96.0 ± 17.4% and exhibited a significant relationship with PBET gastric phase (r² = 0.578, p = 0.080), small intestinal phase (r² = 0.728, p = 0.031) and total BDE-209 bioaccessibility (r² = 0.728, p = 0.031), which indicated PBET assay can serve as a surrogate to predict BDE-209 RBA to refine human health exposure. In addition, the absorption of BDE-209 by Caco-2 cell line was assessed. With the consideration of the corresponding bioaccessibility and absorption of BDE-209 by Caco-2 cell line, the human daily intake of BDE-209 via dust ingestion for adults and children was much lower than that estimated by total concentration. Copyright © 2016 Elsevier Ltd.