Human exposure to soil contaminants in subarctic Ontario, Canada

• Published in: International Journal of Circumpolar Health
• Main Authors: Ellen Stephanie Reyes, Eric Nicholas Liberda, Leonard James S. Tsuji
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2015
• Subjects: DDT; soil; soil ingestion; risk assessment; Aboriginal health; Arctic medicine. Tropical medicine; RC955-962; Arctic; Canada; Fort Albany; Circumpolar Health; Human health; International Journal of Circumpolar Health; Subarctic; James Bay
• Online Access: https://doi.org/10.3402/ijch.v74.27357; https://doaj.org/article/d4fda46ed4354380ab4f4758f3779f0d

Background: Chemical contaminants in the Canadian subarctic present a health risk with exposures primarily occurring via the food consumption. Objective: Characterization of soil contaminants is needed in northern Canada due to increased gardening and agricultural food security initiatives and the presence of known point sources of pollution. Design: A field study was conducted in the western James Bay Region of Ontario, Canada, to examine the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethane and its metabolites (ΣDDT), other organochlorines, and metals/metalloids in potentially contaminated agriculture sites. Methods: Exposure pathways were assessed by comparing the estimated daily intake to acceptable daily intake values. Ninety soil samples were collected at random (grid sampling) from 3 plots (A, B, and C) in Fort Albany (on the mainland), subarctic Ontario, Canada. The contaminated-soil samples were analysed by gas chromatography with an electron capture detector or inductively coupled plasma mass spectrometer. Results: The range of ΣDDT in 90 soil samples was below the limit of detection to 4.19 mg/kg. From the 3 soil plots analysed, Plot A had the highest ΣDDT mean concentration of 1.12 mg/kg, followed by Plot B and Plot C which had 0.09 and 0.01 mg/kg, respectively. Concentrations of other organic contaminants and metals in the soil samples were below the limit of detection or found in low concentrations in all plots and did not present a human health risk. Conclusions: Exposure analyses showed that the human risk was below regulatory thresholds. However, the ΣDDT concentration in Plot A exceeded soil guidelines set out by the Canadian Council of Ministers of the Environment of 0.7 mg/kg, and thus the land should not be used for agricultural or recreational purposes. Both Plots B and C were below threshold limits, and this land can be used for agricultural purposes.