The utility of regional cancer mortality data for identifying occupations at high risk

Mortality rates by geographic areas have been used successfully in the past to identify occupations with a high risk of cancer. The 1975 Atlas of Cancer Mortality for U.S. Counties: 1950-1969 for white males showed that mortality rates in three California counties (Alameda, Sacramento, and San Francisco) were significantly elevated compared to other US counties, and in Sacramento County the lung cancer death rate was significantly high also. This current study was to determine if the excess in the cancer mortality rate found in Sacramento County was possibly related to specific occupational categories. Death certificates for all white males dying of cancer were retrieved, Last occupation, industry, and length of service were coded according to the Index of Industries and Occupations prepared by the US Bureau of the Census. Observed frequencies of cancer deaths were compared to an expected number which was based on US census data by occupation for Sacramento County. Elevated standardized mortality ratios (SMRs) for cancer deaths were found for technicians, metal craftsmen, nonfarm laborers, construction workers, and drivers. SMRs were high for cancer of the esophagus, pancreas, respiratory tract, skin, and central nervous system.