Arctic ice records show massive early 20th century copper Mine pollution

Researchers from the Desert Research Institute (DRI) used Arctic ice cores to identify a massive historical source of air pollution originating from the Anaconda Copper Mine in Montana, United States.

By analyzing 10 ice cores from Greenland, the Russian Arctic, and northern Canada, the team reconstructed atmospheric levels of arsenic and other toxic heavy metals during the Second Industrial Revolution. They found that pollution peaked between 1886 and 1918, reaching levels 15 times higher than pre-Industrial Revolution levels.

The team linked these spikes to the Anaconda Copper Mine, which was one of the world's largest copper producers at the time. Using atmospheric modeling and historical records, the researchers estimated that the mine emitted 11,000 tons of arsenic and 4,400 tons of lead annually during its peak production years. This pollution plume traveled across the continent, reaching as far as western Greenland, more than 4,000 kilometers away.

The study indicates that this historical pollution had widespread health consequences for people living downwind. The researchers estimated that 50.5 million Americans and 600,000 Canadians were exposed to arsenic levels associated with a higher risk of lung cancer. Additionally, 1.4 million people in North America were exposed to lead levels potentially linked to a reduction of 2.6 IQ points.

The data shows that the mine delayed installing pollution controls for a decade, which caused an additional 60,000 tons of arsenic to enter the atmosphere.