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TitleSpatiotemporal patterns of mercury accumulation in lake sediments of western North America
AuthorDrevnick, P E; Cooke, C A; Barraza, D; Blais, J M; Coale, K H; Cumming, B F; Curtis, C J; Das, B; Donahue, W F; Eagle-Smith, C A; Engstrom, D R; Fitzgerald, W F; Furl, C V; Gray, J E; Hall, R I; Jackson, T A; Laird, K R; Lockhart, L W; Macdonald, R W; Mast, A M; Mathieu, C; Muir, D C G; Outridge, P M; Reinemann, S A; Rothenberg, S E; Ruiz-Fernandez, A C; St.Louis, V L; Sanders, R D; Sanei, H; Skierszkan, E K; Van Metre, P C; Veverica, T J; Wiklund, J A; Wolfe, B B
SourceScience of the Total Environment vol 568, 2016 p. 1157-1170,
Alt SeriesEarth Sciences Sector, Contribution Series 20160371
PublisherElsevier BV
Mediapaper; on-line; digital
File formatpdf
ProvinceAlberta; British Columbia; Saskatchewan; Yukon
AreaWestern North America; Canada; United States of America; Mexico
Lat/Long WENS-166.0000 -100.0000 72.0000 20.0000
Subjectsenvironmental geology; geochemistry; mercury; mercury geochemistry; heavy metals contamination; lake sediment cores; lake sediments; sedimentation rates; lake water geochemistry; mine waste products
Illustrationslocation maps; tables; geochemical plots; graphs
AbstractFor theWestern North AmericaMercury Synthesis, we compiled mercury records from165 dated sediment cores from138 natural lakes acrosswestern North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and inferential statistics. Mercury accumulation rates in sediments have increased, on average, four times (4×) from 1850 to 2000 and continue to increase by approximately 0.2 ?g/m2 per year. Lakes with the greatest increases were influenced by the Flin Flon smelter, followed by lakes directly affected by mining and wastewater discharges. Of lakes not directly affected by point sources, there is a clear separation in mercury accumulation rates between lakes with no/little watershed development and lakes with extensive watershed development for agricultural and/or residential purposes. Lakes in the latter group exhibited a sharp increase in mercury accumulation rates with human settlement, stabilizing after 1950 at five times (5×) 1850 rates. Mercury accumulation rates in lakeswith no/little watershed developmentwere controlled primarily by relative watershed size prior to 1850, and since have exhibitedmodest increases (in absolute terms and compared to that described above) associatedwith (regional and global) industrialization. A sub-regional analysis highlighted that in the ecoregion Northwestern Forest Mountains, b1% of mercury deposited to watersheds is delivered to lakes. Research is warranted to understandwhether mountainous watersheds act as permanent sinks formercury or if export of “legacy” mercury (deposited in years past) will delay recovery when/if emissions reductions are achieved.