Temporal variations in lead concentrations and isotopic composition in the Southern California Bight
Temporal variations in lead concentrations and isotopic composition in the Southern California Bight
复制标题
南加州湾铅浓度和同位素组成的时间变化
DOI：
10.1016/0016-7037(94)90060-4
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发表时间：
1994
影响因子：
5
通讯作者：
A. Flegal
中科院分区：
文献类型：
--
作者：
S. Sañudo;A. Flegal
自20世纪70年代Clair Patterson及其同事首次测量以来，南加州湾表层沃茨中的铅浓度似乎已经下降了三倍（从> 170 pM降至< 60 pM）。这一减少与过去二十年来工业铅的人为投入减少了三倍相平行。此外，质量平衡计算表明，现在海湾的主要铅源是上升流。海湾表层沃茨的同位素组成证明了这一点，这是亚洲工业铅气溶胶（0.4793≤ 206 Pb 208 Pb≤ 0.4833）沉积在北太平洋大洋沃茨中的最大特征。虽然海湾表层水铅浓度的降低反映了美国工业铅排放的减少，但海湾南部表层沃茨的同位素组成反映了墨西哥工业铅排放的同时增加（0.4852≤ 206 Pb 208 Pb≤ 0.4877）。圣地亚哥湾表层沃茨铅浓度升高的同位素组成（208 Pb 207 Pb 2.427）表明，铅正从该海湾内受污染的沉积物中被再活化。
Lead concentrations in surface waters of the Southern California Bight appear to have decreased threefold (from> 170 to< 60 pM) since they were initially measured by Clair Patterson and his associates in the 1970s. The decrease parallels a threefold decline in anthropogenic inputs of industrial lead to the bight over the past two decades. Moreover, mass balance calculations indicate that the primary source of lead to the bight now is upwelling. This is evidenced by the isotopic compositions of surface waters in the bight, which are most characteristic of Asian industrial lead aerosols (0.4793≤ 206 Pb 208 Pb≤ 0.4833) deposited in oceanic waters of the North Pacific. While the decrease in surface water lead concentrations in the bight reflects the reduction in industrial lead emissions from the United States, the isotopic compositions of surface waters in the southern reach of the bight reflect a concurrent increase in industrial lead emissions from Mexico (0.4852≤ 206 Pb 208 Pb≤ 0.4877). The isotopic composition (208 Pb 207 Pb≈ 2.427) of elevated lead concentrations of surface waters in San Diego Bay indicate that lead is being remobilized from contaminated sediments within that bay.