ScienceDaily: Leaded gasoline was a larger emission source of the toxic heavy metal lead than mining in South America -- even though the extraction of metals from the region's mines historically released huge quantities of lead into the environment. Researchers from the Paul Scherrer Institute PSI and the University of Bern have discovered evidence of the dominance of leaded gasoline based on measurements in an ice core from a Bolivian glacier. The scientists found that lead from road traffic in the neighbouring...