California's gold-mining history is haunting. Specifically, it's the lingering mess and natural resources left behind by the Gold Rush that has now proven to be toxic.
The Sierra Fund on Tuesday released a study that shows extremely high levels of lead, arsenic and asbestos in soil samples taken from trails in the Sierra Nevada foothills. Outdoor buffs who hike, bike and ride all-terrain vehicle on the off-road trailways could inhale dangerous dust stirred up while using the trails, the group says.
"More than 100 years after the end of the Gold Rush era, the environmental, cultural and health impacts of that time have still not been assessed or addressed." Sierra Fund CEO Elizabeth Martin said. "The time has come for a serious assessment of abandoned mines, and the public needs to be informed about potential exposure to toxic heavy metals and asbestos in areas with abandoned mines."
Gold miners brought mineralized rocks from deep below the surface, crushed and processed the precious gold, leaving behind the naturally occuring hazardous minerals.
Although the group only used samples from 11 of the trails in the Foresthill, Downieville and Nevada City area, they warn of dangers from the nearly 50,000 abandoned mines in the Gold Rush region. The summer months are especially bad for the trails because of heat and drier air.
Some of the areas tested showed "off-the-charts level of lead in the soil on trails where families ride OHVs," according to the non-profit.
Many of the abandonded mines are located on public land, and while the dangers of falling into mines is commmonly known, the dangers of chemicals toxic dust are less apparent, the Sierra Fund study points out.
The group says more tests are needed in selected areas where trails and abandonded mines meet. Posting warning signs, surveying people who frequent the trails and educating the public about exposure to the dangerous dust is also on the group's list recommendations.