Water Quality Monitoring & Surveillance, Environment Canada, 867 Lakeshore Road, Burlington, ON L7R 4A6, Canada.
Environ Pollut. 2012 Feb;161:328-34. doi: 10.1016/j.envpol.2011.06.004. Epub 2011 Jun 28.
Environment Canada recently developed a clean method suitable for sampling trace levels of metals in surface waters. The results of sampling for total mercury in the Laurentian Great Lakes between 2003 and 2009 give a unique basin-wide perspective of concentrations of this important contaminant and represent improved knowledge of mercury in the region. Results indicate that concentrations of total mercury in the offshore regions of the lakes were within a relatively narrow range from about 0.3 to 0.8 ng/L. The highest concentrations were observed in the western basin of Lake Erie and concentrations then declined towards the east. Compared to the offshore, higher levels were observed at some nearshore locations, particularly in lakes Erie and Ontario. The longer-term temporal record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease in equivalent water concentrations since 1986.
加拿大环境部最近开发了一种适用于采集地表水中痕量金属的清洁方法。2003 年至 2009 年间对大湖地区总汞的采样结果提供了一个独特的全流域视角，使人们对这一重要污染物的浓度有了更好的了解。结果表明，湖泊远岸地区总汞的浓度范围相对较窄，约为 0.3 至 0.8ng/L。在安大略湖西部，浓度最高，然后向东递减。与远岸相比，一些近岸地区的浓度更高，特别是在伊利湖和安大略湖。尼亚加拉河悬浮沉积物中汞的长期时间记录表明，自 1986 年以来，等效水浓度约下降了 30%。
