摘要 : Due to the scarcity of metal concentration data for indoor environments, many studies rely on exterior soil geochemical data for predicting indoor exposures. This study demonstrates that existing predictive models do not hold for ... 展开 Due to the scarcity of metal concentration data for indoor environments, many studies rely on exterior soil geochemical data for predicting indoor exposures. This study demonstrates that existing predictive models do not hold for the city of Ottawa, where there is a lack of spatial correlation between elemental concentrations in indoor dust and outdoor soil, indicating a high degree of variability of indoor/outdoor concentration ratios. "Total metal concentrations" are determined in house dust and soil samples using an aggressive combination acid digestion procedure and "migratable metal concentrations" are determined using a simulated stomach acid digestion procedure. Geometric mean indoor/outdoor ratios calculated using the total extraction method are: 5.5 for Pb, 16.4 for Cd, and 3.4 for Ni (based on measurements in 48 Ottawa houses). Indoor/outdoor ratios calculated using the migratable extraction method are: 24.8 for Pb, 20.7 for Cd, and 40.4 for Ni. Organic matter content is elevated in house dust (20-34 %) compared to exterior soil (4%), and organic matter correlates positively with migratable concentrations of Pb, Cu and Ni. It is concluded that the consistently higher total and migratable concentrations and relative bioavailability factors in house dust compared to soil is largely explained by the affinity of these metals for organic components of dust. 收起