Lead contamination of subarctic lakes and its response to reduced atmospheric fallout: can the recovery process be counteracted by the ongoing climate change?
2010 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 44, no 7, 2335-2340 p.Article in journal (Refereed) Published
Can a climate-triggered export of old contaminants from the soil alter the lead (Pb) contaminant burden of subarctic lakes? To address this question, we reconstructed the pollution history of three high latitude lakes situated in a region where a recent climatic shift has occurred. Dated sediment records were used as archives of past Pb inputs to the lakes, where the difference in the 206Pb/207Pb ratio between atmospheric contaminants (206Pb/207Pb ratio <1.16) and geogenic Pb in the catchment soil (206Pb/207Pb ratio >1.22) were used to trace fluxes of Pb contaminants. Lead contaminants were found in sediments deposited since Roman times. A significant export of Pb from the soil contaminant pool is indicated in two of the lakes surrounded by near-shore permafrost soils. Here, levels of Pb contaminants and 206Pb/207Pb ratios of sediments deposited after the 1970s appear not to have been strongly affected by the ≥90% reduction in atmospheric deposition rates and increasing 206Pb/207Pb ratios of atmospheric Pb since the 1990s. We concluded that soil processes stimulated by the ongoing climate change at high latitudes might work counteractive to efforts to reduce contaminant levels in subarctic lakes.
Place, publisher, year, edition, pages
2010. Vol. 44, no 7, 2335-2340 p.
IdentifiersURN: urn:nbn:se:umu:diva-33292DOI: 10.1021/es903025zISI: 000275993700019PubMedID: 20170181OAI: oai:DiVA.org:umu-33292DiVA: diva2:311296