The term “naturally occurring asbestos” or “NOA” refers to the mineral as a natural component of soils or rocks as opposed to asbestos in commercial products, mining or processing operations. Asbestos is most commonly found in three rock types: serpentinites, altered ultramafic rocks, and some mafic rocks. Asbestos can be released from these rocks by natural weathering process or human activities such as mining, construction and land development, resulting contamination of soil and water. Therefore, areas with NOA in soils and sediments are a potential source of exposure for nearby populations. According to USGS, there are at least 35 states in the US reported NOA locations and hundreds worldwide

The potential environmental hazards and associated public health issues related to exposure to asbestos fibers from the vicinity of NOA have gained the regulatory and media spotlight in many areas around the United States, such as Libby, MT, Fairfax County, VA, and El Dorado Hills, CA, among others. In addition to California which regulates NOA under the Department of Toxic Substance Control (DTSC) and California Air Resources Board (ARB), several other states such as CO, WY, NV, and MN have also published guidance or directives on NOA management.

It is imperative that customers such as DOT contractors, geotech engineers, and brownfield cleanup environmental engineers get their soil and rock samples tested for the presence of NOA prior to construction of dams, bridges, highways, or land development. Eurofins Built Environment Testing can provide all levels of soil and rock analysis for the presence of naturally occurring asbestos using both polarized light microscopy (PLM) and transmission electron microscopy (TEM). Our analytical results can provide customers the crucial information they need for managing NOA and protecting their employees as well as the general public from potential exposure to asbestos health hazard. These data are also necessary for environmental scientists to conduct risk assessments in developing science-based public health policies.

The USGS provides updates on this source of asbestos exposure.