title: Soil ingestion rate determination in a rural population of Alberta, Canada practicing a wilderness lifestyle.
abstract: The inadvertent ingestion of contaminated soil can be a major pathway for chemical exposure to humans. Few studies to date have quantified soil ingestion rates to develop exposure estimates for human health risk assessments (HHRA), and almost all of those were for children in suburban/urban environments. Here we employed a quantitative mass balance tracer approach on a rural population practicing outdoor activities to estimate inadvertent soil ingestion. This study followed 9 subjects over a 13 day period in Cold Lake, Alberta, near the largest in situ thermal heavy oil (bitumen) extraction operation in the world. The mean soil ingestion rate in this study using Al Ce, La, and Si tracers was 32 mg d(-1), with a 90th percentile of 152 mg d(-1) and median soil ingestion rate of 18 mg d(-1). These soil ingestion values are greater than the standard recommended soil ingestion rates for HHRA from Health Canada, and are similar to soil ingestion estimates found in the only other study on a rural population.
authors.affiliation: 30 Marie Curie, Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5. Electronic address: graham.irvine@uottawa.ca.
authors.forename: G
authors.initials: G
authors.lastname: Irvine
authors.affiliation: 30 Marie Curie, Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5. Electronic address: jamiedoyle@sympatico.ca.
authors.forename: J R
authors.initials: JR
authors.lastname: Doyle
authors.affiliation: 30 Marie Curie, Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5. Electronic address: paul.white@hc-sc.gc.ca.
authors.forename: P A
authors.initials: PA
authors.lastname: White
authors.affiliation: 30 Marie Curie, Pvt., Department of Biology, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5. Electronic address: jules.blais@uottawa.ca.
authors.forename: J M
authors.initials: JM
authors.lastname: Blais
mesh_terms: D000416:Alberta; D004032:Diet / Q000706:statistics & numerical data*; D004435:Eating; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D005243:Feces / Q000737:chemistry; D006801:Humans; D018570:Risk Assessment; D012424:Rural Population / Q000706:statistics & numerical data*; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D055814:Wilderness
chemical_list: D012987:Soil; D012989:Soil Pollutants
keywords: Aboriginal; Alberta oil sands; In-situ bitumen extraction; Mass balance; Risk assessment; Soil ingestion