Spatial patterns and temporal trends in mercury concentrations, precipitation depths, and mercury wet deposition in the North American Great Lakes region, 2002-2008

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• 作者：Martin R. Risch^a ; ^{mrrisch@usgs.gov} ; David A. Gay^b ; ^{dgay@illinois.edu} ; Kathleen K. Fowler^a ; ^{kkfowler@usgs.gov} ; Gerard J. Keeler^c ; Sean M. Backus^d ; ^{sean.backus.ec.gc@gmail.com} ; Pierrette Blanchard^e ; ^{pierrette.blanchard@ec.gc.ca} ; James A. Barres^f ; ^{jbarres@umich.edu} ; J. Timothy Dvonch^g ; ^{dvonch@umich.edu}
• 关键词：Mercury ; Wet deposition ; Great Lakes ; Spatial patterns ; Temporal trends
• 刊名：Environmental Pollution
• 出版年：2012
• 出版时间：February 2012
• 年：2012
• 卷：161
• 期：Complete
• 页码：261-271
• 全文大小：2801 K

文摘

Annual and weekly mercury (Hg) concentrations, precipitation depths, and Hg wet deposition in the Great Lakes region were analyzed by using data from 5 monitoring networks in the USA and Canada for a 2002-2008 study period. High-resolution maps of calculated annual data, 7-year mean data, and net interannual change for the study period were prepared to assess spatial patterns. Areas with 7-year mean annual Hg concentrations higher than the 12?ng per liter water-quality criterion were mapped in 4 states. Temporal trends in measured weekly data were determined statistically. Monitoring sites with significant 7-year trends in weekly Hg wet deposition were spatially separated and were not sites with trends in weekly Hg concentration. During 2002-2008, Hg wet deposition was found to be unchanged in the Great Lakes region and its subregions. Any small decreases in Hg concentration apparently were offset by increases in precipitation.