Seasonal variation of arsenic and antimony in surface waters of small subarctic lakes impacted by legacy mining pollution near Yellowknife, NT, Canada

• Published in: Science of The Total Environment
• Main Authors: Palmer, M.J. (Michael J.), Chételat, J. (John), Richardson, M. (Murray), Jamieson, H.E. (Heather E.), Galloway, J.M. (Jennifer M.)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Antimony; Arsenic; Cryoconcentration; Seasonality; Sediment efflux; Subarctic lakes; Northwest Territories; Yellowknife; Canada; Subarctic
• Online Access: https://ir.library.carleton.ca/pub/24489; https://doi.org/10.1016/j.scitotenv.2019.05.258

The seasonal variation in lake water arsenic (As)and antimony (Sb)concentrations was assessed in four small (<1.5 km2)subarctic lakes impacted by As and Sb emissions from legacy mining activities near Yellowknife, Northwest Territories, Canada. Substantial variation in As concentrations were measured over the two-year period of study in all but the deepest lake (maximum depth 6.9 m), including a four-fold difference in As in the shallowest lake ([As]: 172–846 μg L−1; maximum depth 0.8 m). Arsenic concentrations were enriched following ice cover development in the three shallowest lakes (50–110%)through a combination of physical and biogeochemical processes. Early winter increases in As were associated with the exclusion of solutes from the developing ice-cover; and large increases in As were measured once oxygen conditions were depleted to the point of anoxia by mid-winter. The onset of anoxic conditions wit