Mercury contamination in California to last 10,000 years
Toxic remnants of gold rush will seep into San Francisco area waterways for millennia
By Jessica Shugart, 11:43 AM October 28, 2013
California’s gold rush ended more than a century ago, but the contamination it caused will last thousands of years, a new analysis shows.
Some hydraulic gold mining processes use the toxic metal mercury to separate gold from gravel. In the mid-1800s, gold mining released more than a cubic kilometer of mercury-laden sediments into Northern California’s Sierra Nevada foothills. The sediments fanned out and inundated rivers that flow into the San Francisco Bay. Researchers estimate that 90 percen...
Source URL: https://www.sciencenews.org/article/mercury-contamination-california-last-10000-years?mode=magazine&context=187368