Trace Elements in Rain

Boutron et al. (1991) studied the change in atmospheric emissions of Cd, Pb, and Zn before and after 1971 by analyzing Greenland ice cores. They found that Pb values were 200 times higher in 1971 than before the industrial revolution, with 99% of the lead from anthropogenic sources. Since 197 and the introduction of unleaded gasoline, atmospheric lead values have declined by 7.5 times in the United States. The same authors also reported that Cd and Zn concentrations in the ice have 

General Controls on Natural Water Chemistry Chap. 8 

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