Goulet Richard R, Lalonde J D, Chapleau F, Findlay S C, Lean D R S
Canadian Nuclear Safety Commission, Environmental Risk Assessment Division, P.O. Box 1046, Station B, Ottawa, Ontario, K1P 5S9, Canada.
Arch Environ Contam Toxicol. 2008 May;54(4):716-29. doi: 10.1007/s00244-007-9080-7.
The Massena (New York) and Cornwall (Ontario) region has a long history of Hg discharge into the St. Lawrence River. The objectives of this study were to evaluate if Hg levels have declined in this portion of the river since 1975 and to compare Hg level in fish species upstream and downstream of this area in order to evaluate the anthropogenic contribution to Hg levels in fish. Mercury levels in four fish species were monitored over a 20-year period (1975-1995). A general linear model and an analysis of covariance were used to extract temporal trends and spatial variability, respectively, while correcting the data for fish length. Over time, Hg levels declined in most fish species. In the four regions studied, Hg levels in fish were similar, which suggests that other sources like atmospheric deposition and Hg loading from the Great Lakes may also contribute to the Hg burden in fish in the St. Lawrence River. This indicates that fish, with large home range, are good biomonitors of temporal Hg releases but their ability to avoid point sources makes them less appealing as biomonitors to address spatial variability in Hg releases.
纽约州马塞纳市和安大略省康沃尔市所在地区长期以来一直向圣劳伦斯河排放汞。本研究的目的是评估自1975年以来该河段汞含量是否下降，并比较该区域上下游鱼类的汞含量，以评估人为因素对鱼类汞含量的影响。在20年期间（1975年至1995年）对四种鱼类的汞含量进行了监测。使用一般线性模型和协方差分析分别提取时间趋势和空间变异性，同时对鱼的长度数据进行校正。随着时间的推移，大多数鱼类的汞含量下降。在所研究的四个区域中，鱼类的汞含量相似，这表明大气沉降和五大湖的汞负荷等其他来源也可能导致圣劳伦斯河鱼类的汞负担。这表明，活动范围大的鱼类是汞随时间释放的良好生物监测指标，但它们避开点源的能力使其作为解决汞释放空间变异性的生物监测指标吸引力降低。
