Traces of Asbestos Found During Nevada’s I-11 Route Construction

Illustration of potential asbestos exposure in a building

The Nevada Transportation Department work on the planned Interstate 11 Boulder City bypass resulted in the discovery of naturally occurring asbestos (NOA) in December 2013. The numbers are now in and officials will be required to spend $12.7 million for abatement the toxic mineral and to monitor the air while the work is occurring.

Two UNLV professors, Rodney Metcalf, Ph.D. Geology, and Brenda Buck, Ph.D. Soil Science, examined the rocks that contained asbestos. Buck was testing for arsenic and other toxic chemicals when she found actinolite, a type of asbestos.

Asbestos is produced naturally through geological processes and typically buried harmlessly in the earth. Exposure to asbestos happens when the carcinogenic fibers are disturbed or broken and become friable.

The health risks associated the substance can lead to the deadly mesothelioma cancer. Dr. Buck’s paper concluded that the Boulder City area asbestos is “highly respirable and possibly carcinogenic.” She suggests a further study to fully assess the public health risk.

When the asbestos becomes worn or damaged, such as during construction, the fibers may flake off and become airborne. Anyone in the vicinity who inhales the toxic fibers could get them embedded in his or her chest. Dr. Buck is continuing to study southern Nevada to understand the extent of the naturally occurring asbestos, but has declined graduate student assistance because she considers the work so hazardous.

The highest concentration of asbestos along the I-11 route was discovered close to where the groundbreaking event took place—2 miles north of Mike O’Callaghan-Pat Tillman Memorial Bridge across the Colorado River.

The U.S. Environmental Protection Agency is still evaluating how to manage NOA—asbestos in areas where it occurs naturally. The actinolite type found on-site in this case was made predominantly of magnesium, is extremely rare, and ranges in color from white to dark brown.

“This completely blindsided me,” said Governor Brian Sandoval, “and it isn’t a small amount of money.” Asbestos is rare to find during Nevada road projects so equipment and expertise will have to be taken care of by a hired consultant.

Personnel is to include two inspectors, two or more testers, an office manager, a part-time scheduler, an asbestos specialist, a dust-control monitor, a geologist, and a Nevada-certified environmental engineer.

$8 million will be provided by the Nevada Transportation Department for the equipment and necessary personnel of its 2.5-mile part of the 15-mile route. Department Director Rudy Malfabon said an additional $5 million is needed for monitoring and inspections, including nuclear gauges, trucks, and cellphones.

The second contract has committed $4.7 million for asbestos mitigation by the Regional Transportation Commission of Southern Nevada. Both projects will last up to three years.