naturally occurring asbestos (NOA)

Naturally occurring asbestos (NOA) is asbestos found in nature in various minerals, such as chrysotile, crocidolite, amosite, anthophyllite, tremolite, actinolite, and serpentinite. Undisturbed, these minerals may have little to no impact on the environment and human health. However, weathering, mining, real estate development, and construction may emit asbestos fibers into the atmosphere, exposing the workforce and communities to unknown respiratory hazards.