title: Impact of closing Canada's largest point-source of mercury emissions on local atmospheric mercury concentrations.
abstract: The Flin Flon, Manitoba copper smelter was Canada's largest point source of mercury emissions until its closure in 2010 after ~80 years of operation. The objective of this study was to understand the variables controlling the local ground-level air mercury concentrations before and after this major point source reduction. Total gaseous mercury (TGM) in air, mercury in precipitation, and other ancillary meteorological and air quality parameters were measured pre- and postsmelter closure, and mercury speciation measurements in air were collected postclosure. The results showed that TGM was significantly elevated during the time period when the smelter operated (4.1 ± 3.7 ng m(-3)), decreased only 20% during the year following its closure, and remained ~2-fold above background levels. Similar trends were observed for mercury concentrations in precipitation. Several lines of evidence indicated that while smelter stack emissions would occasionally mix down to the surface resulting in large spikes in TGM concentrations (up to 61 ng m(-3)), the largest contributor to elevated TGM concentrations before and after smelter closure was from surface-air fluxes from mercury-enriched soils and/or tailings. These findings highlight the ability of legacy mercury, deposited to local landscapes over decades from industrial activities, to significantly affect local air concentrations via emissions/re-emissions.
authors: Meteorological Service of Canada, Environment Canada , 4905 Dufferin Street, Toronto, Ontario, M3H 5T4 Canada.
authors: Chris S
authors: CS
authors: Eckley
authors: Matthew T
authors: MT
authors: Parsons
authors: Rachel
authors: R
authors: Mintz
authors: Monique
authors: M
authors: Lapalme
authors: Maxwell
authors: M
authors: Mazur
authors: Robert
authors: R
authors: Tordon
authors: Robert
authors: R
authors: Elleman
authors: Jennifer A
authors: JA
authors: Graydon
authors: Pierrette
authors: P
authors: Blanchard
authors: Vincent
authors: V
authors: St Louis
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D003300:Copper; D004784:Environmental Monitoring; D008350:Manitoba; D008628:Mercury / Q000032:analysis*; D008669:Metallurgy; D052638:Particulate Matter / Q000032:analysis; D013458:Sulfur Dioxide / Q000032:analysis
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D003300:Copper; D008628:Mercury