Mineralogical, geospatial, and statistical methods combined to estimate geochemical background of arsenic in soils for an area impacted by legacy mining pollution
| Autor: | Michael J. Palmer, Murray Richardson, Jon Oliver, Hendrik Falck, Kirsten Maitland, Anežka Borčinová Radková, Heather E. Jamieson |
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| Rok vydání: | 2021 |
| Předmět: |
Pollution
Pollutant geography Environmental Engineering geography.geographical_feature_category 010504 meteorology & atmospheric sciences media_common.quotation_subject Earth science 010501 environmental sciences 15. Life on land Dispersion (geology) 01 natural sciences Subarctic climate Natural (archaeology) Volcano 13. Climate action Soil water Environmental Chemistry Environmental science Soil horizon Waste Management and Disposal 0105 earth and related environmental sciences media_common |
| Zdroj: | Science of The Total Environment. 776:145926 |
| ISSN: | 0048-9697 |
| DOI: | 10.1016/j.scitotenv.2021.145926 |
| Popis: | The estimation of geochemical background is complex in areas impacted by point sources of atmospheric emissions due to unknowns about pollutant dispersion, persistence of pollutants on the landscape, and natural concentrations of elements associated with parent material. This study combined mineralogical analysis with conventional statistical and geospatial methods to separate anthropogenically impacted soils from unimpacted soils in the Yellowknife area, Northwest Territories, Canada, a region that was exposed to 60 years of arsenic (As)-rich atmospheric mining emissions (1938–1999) and that hosts natural enrichments of As. High concentrations of As (up to 4700 mg kg−1) were measured in publicly accessible soils near decommissioned roaster stacks in the region and strong relationships between As and distance from the main emission sources persisted in surface soils and soils at depth in the soil profile more than 60 years after the bulk of mining emissions were released. Mineralogical analysis provided unambiguous evidence regarding the source of As minerals and highlighted that most As in surface soils within 15 km of Yellowknife is hosted as anthropogenic arsenic trioxide (As2O3), produced by roaster stack emissions. Statistical protocols for the estimation of geochemical background were applied to an existing database of till geochemistry (N = 1490) after removing samples from mining impacted areas. Results suggested geochemical background for the region is 0.25–15 mg kg−1 As, comparable to global averages, with upper thresholds elevated in volcanic units (30 mg kg−1 As) that often host sulfide mineralization in greenstone belts in the region. |
| Databáze: | OpenAIRE |
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