Analysis of Mortality in Two California Counties with Asbestos-Bearing Serpentine Mineral Formations

摘要

The purpose of the study was to investigate, with a case/control format, the possible association between ambient asbestos exposure and mortality in three cause of death categories: malignant neoplasms of digestive system; malignant neoplasms of bronchus and lung; and hypertensive heart disease. Using state mortality tapes, county decedents from each of the above case groups from 1969 to 1977 were selected, along with matched control decedents from categories of death thought to be unrelated to asbestos. Each decedent was assigned an asbestos exposure index, based upon the proximity of their place of residence to asbestos deposits. Associations (measured by odds ratios) between place of residence and cause of death were not great for any of the three causes studied; however, mortality for lung cancer showed the most consistent associations in both males and females. This was to be expected, since the environmental measurements indicated that the primary source of ambient asbestos exposure is airborne. This study design has many limitations, however, mainly due to the small sample sizes available, and the reliance on death certificate data.