An Evaluation of Potential Occupational Exposure to Asbestiform Amphiboles near a Former Vermiculite Mine

Table 1

Tree bark sample results—Forest Service land northeast of the former vermiculite mine.

Location 𝑛=(8)	Tree Species	Amphibole structures/cm^2
Alexander Test Site	Tamarack	36,898
Alexander Test Site	Tamarack	158,583
Alexander Test Site	Tamarack	112,336
Rainy Divide Trail 12S	Ponderosa pine	568,137
Rainy Divide Trail 12S	Douglas Fir	12,356,979
Rainy Divide Trail 12S	Douglas Fir	15,383,941
Rainy Divide Trail 12S	Douglas Fir	13,377,926
Bark sample collected in Missoula,	Ponderosa pine	^(a)ND
MT. Serves as control sample

^(a)ND = Nondetect.