Sierra Fund report says some recreational areas are health hazards

Sierra Fund Science Director Dr. Carrie Monohan, left, and Sierra Fund CEO Elizabeth Martin released the report on June 22 at the state capitol in Sacramento.

“Our study documents that these abandoned mines pose a toxic health threat on public lands that are widely used for recreational activities." Elizabeth Martin, CEO of the Sierra Fund

The Sierra Fund released its Gold Country Recreational Trails and Abandoned Mines Assessment on Tuesday and it shows that Off Highway Vehicle (OHV) riders, mountain bikers, hikers and equestrians are using abandoned mine areas that are contaminated with dangerous levels of lead, arsenic and asbestos.

In some cases, these are officially sanctioned recreational trails in national forests that travel through and into abandoned mine lands, old mill sites, mine tailings and waste rock piles, according to the report by the nonprofit, which is based in Nevada City.

 “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,” Elizabeth Martin, the CEO of The Sierra Fund, said.  “Our study documents that these abandoned mines pose a toxic health threat on public lands that are widely used for recreational activities.  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.”

The Sierra Fund’s report, which was released at the state capitol in Sacramento, identifies specific recreation areas around Nevada City, Downieville and Foresthill where popular trails intersect with known abandoned mine sites. In these areas, samples were taken to learn whether the public may be encountering hazardous substances. Contaminants of concern (COC) include lead and arsenic and other hazardous materials such as asbestos.

According to Dr. Carrie Monohan, the Sierra Fund’s science director and principle author of the report: “The purpose of this study was to learn whether people are potentially being exposed to dangerously high levels of heavy metals while engaging in dusty recreation activities in and around abandoned mines. Our results show that this is in fact the case in some areas and more assessment is urgently needed.”

According to the report, toxins were found at levels that could affect human health at the following locations:

·        In the Nevada City area, arsenic was found at levels of concern on Banner Mountain trails, and asbestos in one location on the Newtown Ditch trail used for biking and hiking;  

·        At the Foresthill OHV Area in and around the abandoned Marrall Chrome Mine pit, samples showed up to 40 percent asbestos and “off-the-charts levels” of lead in the soil on trails where OHVs are ridden;

·        In the Downieville area, certain biking, hiking and OHV trail locations tested high for arsenic, lead and asbestos. 

The report did include some good news. It found that several popular areas, including the “Downieville Downhill” mountain bike trails and the Eureka Diggings OHV Area, do not pose a health threat even though they pass several abandoned mines.

The report includes the following recommendations:

Clear, visible advisories are needed in areas that are known to be contaminated by substances that are dangerous to human health;

    Additional sampling of contaminated areas;

A dust exposure study that looks at exposure scenarios of different recreational activities;

A survey of people who use these areas to learn more about their exposure and effective outreach and education methods.

Full copies of this study may be downloaded at The Sierra Fund’s website, www.sierrafund.org.