Evidence from glacier ice: Until it was banned, leaded gasoline dominated the humanmade lead emissions in South America – Science Daily

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 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 countries polluted the air twice as heavily as regional mining from the 1960s onwards. The study is to be published in the journal Science Advances on 6 March 2015.

The use of leaded gasoline was the dominant source of anthropogenic, i.e. human-made, lead emissions in South America from the 1960s onwards. The fuel even surpassed the thriving mining industry in this region of the world, which also releases large quantities of lead. In the past, measurements in the Northern Hemisphere had already revealed that emissions from leaded gasoline exceeded those of mining activities. However, such conclusive evidence was lacking for the Altiplano region in South America. On this plateau, located between the western eastern Andes, extractive metallurgy from mineral ores has been releasing large amounts of lead into the environment since the pre-colonial era.

Evidence of this has now been discovered by researchers from PSI the University of Bern using measurements from a 138 m long ice core, drilled out of the Nevado Illimani
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