Historical Perspective of Industrial Lead Emissions to the Atmosphere from a Canadian Smelter

详细信息    查看全文

• 作者：Cé ; line Gallon ; André ; Tessier ; Charles Gobeil ; and Richard Carignan
• 刊名：Environmental Science & Technology
• 出版年：2006
• 出版时间：February 1, 2006
• 年：2006
• 卷：40
• 期：3
• 页码：741 - 747
• 全文大小：391K
• 年卷期：v.40,no.3(February 1, 2006)
• ISSN：1520-5851

文摘

Dated sediment cores from four remote Canadian Shieldheadwater lakes, where atmospheric deposition has beenthe only input of anthropogenic Pb, situated along atransect extending 300 km from a nonferrous metal smelter,were analyzed for both lead concentrations and isotopiccomposition; porewater samples collected at the same siteswere analyzed for Pb and other geochemical variables.The depth distributions of stable Pb isotope ratios show thepresence of several isotopically distinct Pb types sincethe preindustrial period. Lead from the smelter emissionshad an isotopic signature (e.g., ²⁰⁶Pb/²⁰⁷Pb ~ 0.993) that wasclearly distinct from those of Pb in aerosols collected atsites remote from point sources in Eastern Canada (e.g., ²⁰⁶Pb/²⁰⁷Pb usually ~1.15-1.20) and the United States (e.g., ²⁰⁶Pb/²⁰⁷Pb usually ~1.15-1.22), allowing the geographicalarea impacted by the smelter Pb emissions to be traced.On the basis of the sediment Pb isotopic composition, it isestimated that lead from the smelter accounts for 89%,88%, and 5-34% of the total inventory of anthropogenic Pbdeposited in the sediments of lakes located 10, 25, and150 km from the smelter, respectively; but lead from thispoint source was not detected in sediments of a fourth lakethat is 300 km from the smelter. We also estimate thatthe amount of smelter-derived Pb deposited within a distanceof 150 km is equivalent to 5-10% of the amount releasedby leaded gasoline combustion in all of Canada. Sharpdecreases in the recent Pb fluxes to lake sediments indicatethat the measures taken to mitigate metal emissionsfrom the smelter were effective.