Amerikaanse vermiculiet-mijnwerkers hebben vaker asbestziekten

Mijnwerkers die in de vermiculietmijn van Libby, Montana hebben gewerkt zijn in de periode van 1982 tot en met 2001 vaker overleden aan asbestose, longkanker of mesothelioom dan de gemiddelde Amerikaan. De vermiculiet in de mijn was verontreinigd met het gevaarlijke tremoliet- en amfiboolasbest. Het materiaal werd vooral gebruikt voor de isolatie van huizen. Het aantal asbestose- en longkankersterfgevallen was hoger naarmate men vaker en intensiever was blootgesteld. Bron: Sullivan, P.A. (2007). Vermiculite, respiratory disease and asbestos exposure in Libby, Montana: update of a chohort mortality study. Environ Health Perspect 2007 Jan. :1-38.

Sullivan, P.A. (2007). Vermiculite, respiratory disease and asbestos exposure in Libby, Montana: update of a chohort mortality study. Environ Health Perspect 2007 Jan. :1-38.

Background. Vermiculite from the mine near Libby, Montana, is contaminated with tremolite asbestos and other amphibole fibers (winchite and richterite). Asbestos-contaminated Libby vermiculite was used in loose-fill attic insulation that remains in millions of homes in the U.S., Canada, and other countries.

Objective. This report describes asbestos-related occupational respiratory disease mortality among workers who mined, milled, and processed the Libby vermiculite.

Methods. This historical cohort mortality study uses life table analysis methods to compare the age-adjusted mortality experience through 2001 of 1,672 Libby workers to that of white men in the U.S. population.

Results. Libby workers were significantly more likely to die from asbestosis (standardized mortality ratio [SMR] 165.8. 95% confidence interval [CI] 103.9, 251.1), lung cancer (SMR 1.7. 95% CI 1.4, 2.1), cancer of the pleura (SMR 23.3. 95% CI 6.3, 59.5), and mesothelioma. Mortality from asbestosis and lung cancer increased with increasing duration and cumulative exposure to airborne tremolite asbestos and other amphibole fibers.

Conclusions. The observed dose-related increases in asbestosis and lung cancer mortality highlight the need for better understanding and control of exposures that may occur when homeowners or construction workers (including plumbers, cable installers, electricians, telephone repair personnel, and insulators) disturb loose-fill attic insulation made with asbestoscontaminated vermiculite from Libby, Montana.