Led by Joe McConnell of the Desert Research Institute in Nevada, the team used data from 16 ice cores collected from widely spaced locations around the Antarctic continent to create a record that spans a 410-year period from 1600 to 2010.
The findings show that Antarctic lead concentrations peaked in 1900 and remained high until the late 1920s, before declining briefly during the Great Depression and the end of the Second World War. ‘It’s very clear that industrial lead contamination was pervasive throughout Antarctica by the late 19th century, more than two decades before the first explorers made it to the South Pole,’ McConnell said.
Levels today are about four times higher than before industrialisation, despite the phasing out of leaded petrol and other mitigation efforts. ‘Our measurements indicate that about 660 tonnes of industrial lead have been deposited on the snow-covered surface of the Antarctic during the past 130 years,’ McConnell said. ‘While recent contamination levels are lower, clearly detectable industrial contamination of the Antarctic continent persists today, so we still have a long way to go.’