Lead Pollution Beat South Pole Explorers to the Antarctic

It turns out that pollution may be more widespread than once thought-even in the distant past. Scientists have taken a look at ice cores in the South Pole and have found that lead pollution may have actually arrived in these southern reaches before the first explorers did.

The scientists used data from 16 ice cores collected from widely spaced locations around the Antarctic continent, including the South Pole. Then, the researchers created a reconstruction of lead pollution over the Earth's southernmost continent over a 410-year period, from 1600 to 2010.

 "Our new record shows the dramatic impact of industrial activities such as smelting, mining, and fossil fuel burning on even the most remote parts of the world," said Joe McConnell, the lead author of the new study, in a news release. "It is very clear that industrial lead contamination was pervasive throughout Antarctica by the late 19^th century, more than two decades before the first explorers made it to the South Pole."

What was even more interesting was that it's likely that there was a single emission source in southern Australia that first introduced the lead pollution into Antarctica at the end of the 19^th century. In addition, the lead concentrations in the Antarctic peaked in 1900 and then remained high until the late 1920s. There were brief declines during the Great Depression and the end of World War II. These concentrations increased rapidly until 1975 and then remained elevated until the 1990s. Since then, concentrations have declined.

"Our measurements indicate that approximately 660 tons (1.5 million pounds) of industrial lead have been deposited on the snow-covered surface of Antarctic during the last 130 years," said McConnell. "While recent levels are lower, clearly detectable industrial contamination of the Antarctic continent persists today...so we still have a ways to go."

The findings are published in the journal Scientific Reports.