Dust blown by wind and kicked up by off-road vehicles and motorcycles at Nellis Dunes Recreation Area contains high levels of naturally occurring arsenic and has the presence of an asbestos-like mineral, according to a study released Thursday by the Bureau of Land Management.
A BLM spokeswoman said the 10,000-acre recreation area will remain open while a health risk assessment is completed over the next three years, but advisory signs will posted at the recreation area with more information available at the bureau's Southern Nevada District Office website: www.blm.gov/nv/st/en/fo/lvfo.html.
"The area remains open, but it's the people's decision about going out there and what they feel comfortable with," BLM spokeswoman Kirsten Cannon said.
About 300,000 off-road enthusiasts and visitors a year use the recreation area, which is north of Nellis Air Force Base and southeast of Interstate 15 in the north Las Vegas Valley.
The study was conducted by the University of Nevada, Las Vegas as part of a dust mitigation plan submitted to Clark County officials for meeting federal air quality standards.
"BLM does not know whether the elevated levels of arsenic pose a health risk to recreational and other users of the Nellis Dunes Recreation Area," BLM officials said in a news release.
Preliminary data from a health risk assessment will be released to the public as the data become available before the assessment is completed. Cannon said the BLM's Southern Nevada District Office will be receiving reports on the assessment every six months.
"If the materials identified in the dust study are found to pose a potential threat to human health and safety, the Health Risk Assessment will help BLM determine what, if any, safety measures should be taken," the news release said.
Levels of arsenic, a possible cancer-causing and sometimes fatal element, were found at Nellis Dunes Recreation Area to be up to almost 10 times more than arsenic found in soils elsewhere in the United States.
There are no standards for arsenic levels in U.S. recreational settings.
According to the Environmental Protection Agency, human inhalation studies have found inorganic arsenic exposure to be strongly associated with lung cancer. Other health effects include stomach and skin problems and irritation of mucous membranes from chronic inhalation of arsenic.
With the substantially higher concentrations of arsenic in soil at the Nellis Dunes Recreation Area, the dust study also found that nearly all samples contained palygorskite, a fibrous clay mineral that has many of the same characteristics as asbestos.
Palygorskite is not regulated like asbestos and is naturally occurring. Researchers think that it has potential to cause lung disease and that its long fibers are possibly carcinogenic to humans.