Journal of Thoracic Oncology 2015 February 7 [Epub ahead of print] [Link]

Baumann F, Buck BJ, Metcalf RV, McLaurin BT, Merkler D, Carbone M.

Abstract

Background

Inhalation of asbestos and other mineral fibers are known causes of malignant mesothelioma (MM) and lung cancers. In a setting of occupational exposure to asbestos, MM occurs 4-8 times more frequently in men than in women, at the median age of 74 years, while an environmental exposure to asbestos causes the same number of MMs in men and women, at younger ages.

Methods

We studied the geology of Nevada to identify mineral fibers in the environment. We compared MM mortality in different Nevada Counties, per sex and age group, for the 1999-2010 period.

Results

We identified the presence of carcinogenic minerals in Nevada, including actinolite asbestos, erionite, winchite, magnesioriebeckite and richterite. We discovered that, compared with the US and other Nevada counties, Clark and Nye counties, in southern Nevada, had a significantly higher proportion of MM that occurred in young individuals (<55 years) and in women.

Conclusions

The elevated percentage of women and individuals younger than 55 years old, combined with a sex ratio of 1:1 in this age group and the presence of naturally occurring asbestos, suggests that environmental exposure to mineral fibers in southern Nevada may be contributing to some of these mesotheliomas. Further research to assess environmental exposures should allow the development of strategies to minimize exposure, as the development of rural areas continues in Nevada, and to prevent MM and other asbestos-related diseases.