A century-old pollution trail leads scientists back to Montana mining

At the turn of the twentieth century, the Anaconda Smelter in Montana spewed arsenic into the air — those heavy metal particles that are now trapped in Arctic ice cores.

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At the turn of the twentieth century, the Anaconda Smelter in Montana spewed arsenic into the air — those heavy metal particles that are now trapped in Arctic ice cores.

H.C. White Co./Wikimedia Commons

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Ice cores record Earth’s secrets, even the dirty ones.

Some of the cylindrical sections of ice extracted from the Arctic contain elevated levels of arsenic, lead and other heavy metals that circulated in our planet’s atmosphere in the late 19th and early 20th centuries.…