Conclusions on worker asbestos exposure at Vermiculite Northwest site

Based on the data reviewed for Vermiculite Northwest and similar sites, ODHS/SHINE concludes the following:

Workers employed at Vermiculite Northwest were exposed to hazardous levels of Libby asbestos as a result of working in and around the facility during unloading and exfoliation of Libby vermiculite. These exposures represent a past public health hazard.

Household contacts of former workers were also likely to have been exposed to Libby asbestos brought home on clothing and hair of workers. These exposures represent a past public health hazard.

Workers employed in businesses renting the remainder of the facility during the years W.R. Grace occupied a portion of the building may have been exposed to asbestos. Not enough information is available to determine the extent of exposure for this group of workers. Exposure to contaminated dust at the site for workers in collocated businesses from 1950 to 1980 is an indeterminate public health hazard.

Workers employed in businesses occupying the facility subsequent to its sale by WR. Grace, may have been exposed to asbestos. Although the exposure would have been much less than for the vermiculite processing workers, the actual level of exposure is unknown. Current EPA sampling has detected the presence of fibers consistent with Libby asbestos at the facility suggesting that further cleanup is warranted. Exposure to contaminated dust at the site from 1994 to present is considered an indeterminate public health hazard for workers.

Exposure to soil at the railroad tracks east of the building where vermiculite was unloaded cannot be evaluated until data on asbestos content in the soil is available. Potential exposure to soil in this area is considered an indeterminate public health hazard.

There is not enough information to determine the extent of past exposure to Libby asbestos from air emissions from the plant. Past exposures of nearby residents and workers employed at adjacent businesses to airborne asbestos is an indeterminate public health hazard.

Anecdotal information indicates that some waste rock may have been used off-site. Exposure to asbestos from waste rock is an indeterminate public hazard because information about potential exposures is lacking.