title: Comparison of Gastric versus Gastrointestinal PBET Extractions for Estimating Oral Bioaccessibility of Metals in House Dust.
abstract: Oral bioaccessibility estimates for six metals which are prevalent as contaminants in Canada (zinc, lead, cadmium, copper, nickel, and chromium) are investigated for house dust using the simple gastric phase versus the two-phase physiologically-based extraction technique (PBET). The purpose is to determine whether a complete gastrointestinal (GI) assay yields a more conservative (i.e., higher) estimate of metal bioaccessibility in house dust than the gastric phase alone (G-alone). The study samples include household vacuum dust collected from 33 homes in Montreal, Canada, plus four certified reference materials (NIST 2583, NIST 2584, NIST 2710 and NIST 2710a). Results indicate that percent bioaccessibilities obtained using G-alone are generally greater than or equivalent to those obtained using the complete GI simulation for the six studied metals in house dust. Median bioaccessibilities for G-alone/GI in household vacuum dust samples (n= 33) are 76.9%/19.5% for zinc, 50.4%/6.2% for lead, 70.0%/22.4% for cadmium, 33.9%/30.5% for copper and 28.5%/20.7% for nickel. Bioaccessible chromium is above the detection limit in only four out of 33 samples, for which G-alone results are not significantly different from GI results (p= 0.39). It is concluded that, for the six studied metals, a simple G-alone extraction provides a conservative and cost-effective approach for estimating oral bioaccessibility of metals in house dust.
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, ON K1A 0K9, Canada. kristina.boros@gmail.com.|Department of Earth and Environmental Sciences, University of Ottawa, 25 Templeton St., Ottawa, ON K1N 6N5, Canada. kristina.boros@gmail.com.
authors.forename: Kristina
authors.initials: K
authors.lastname: Boros
authors.affiliation: Department of Earth and Environmental Sciences, University of Ottawa, 25 Templeton St., Ottawa, ON K1N 6N5, Canada. Danielle.Fortin@mac.com.
authors.forename: Danielle
authors.initials: D
authors.lastname: Fortin
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, ON K1A 0K9, Canada. innocent.jayawardene@hc-sc.gc.ca.
authors.forename: Innocent
authors.initials: I
authors.lastname: Jayawardene
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, ON K1A 0K9, Canada. marc.chenier@canada.ca.
authors.forename: Marc
authors.initials: M
authors.lastname: Chénier
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, ON K1A 0K9, Canada. christine.levesque@canada.ca.
authors.forename: Christine
authors.initials: C
authors.lastname: Levesque
authors.affiliation: Environmental Health Science and Research Bureau, HECSB, Health Canada, 50 Colombine Driveway, Tunney's Pasture 0803C, Ottawa, ON K1A 0K9, Canada. pat.rasmussen@canada.ca.|Department of Earth and Environmental Sciences, University of Ottawa, 25 Templeton St., Ottawa, ON K1N 6N5, Canada. pat.rasmussen@canada.ca.
authors.forename: Pat E
authors.initials: PE
authors.lastname: Rasmussen
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002170:Canada; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D019216:Metals, Heavy / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D004391:Dust; D019216:Metals, Heavy
keywords: exposure assessment; gastric; gastrointestinal; house dust; in vitro bioaccessibility; indoor environments; metals