The standardized mortality ratios (SMRs) and standardized rate ratios (SRRs) for uranium miners were updated. Information was obtained for 3,238 white, male uranium miners from the Colorado Plateau study group. Vital status was determined from 1960 to 1990. The working level months (WLMs) of radon progeny exposure were calculated for the cohort members. Of the 3,238 workers investigated, 1,595 were dead. The SMR for all causes was elevated at 1.6. Other elevated SMRs included 3.7 for tuberculosis, 4.8 for breast cancer, 5.8 for lung cancer, and 24.1 for pneumoconiosis. For the 371 workers who died of lung cancer, the mean radon progeny exposure level was 1,574WLMs. The lung cancer rate increased significantly with increasing radon progeny exposure, from an SRR of 1.0 with less than 120WLMs to an SRR of 7.2 with more than 1,000WLMs. The lung cancer rate also increased significantly with increasing duration of employment, with an SRR of 1.0 with less than 5 years of employment to an SRR of 3.9 with greater than 15 years of employment. The SRRs for benign and unspecified tumors increased significantly with increasing duration of employment, ranging from 1.0 with less than 5 years of employment to 3.7 with greater than 15 years of employment. The SRRs for pneumoconiosis also increased significantly with increasing duration of employment, varying from 1.0 with less than 5 years of employment to 19.2 with greater than 15 years of employment. For accidental injuries, the SMR was highest for the workers employed less than 5 years, with a value of 3.9, and lowest for the workers employed more than 15 years, with a value of 2.5. The author concludes that the most serious mortality risks for uranium miners are lung cancer, pneumoconiosis, and chronic obstructive respiratory disease.
NIOSH-Author; Humans; Mortality-rates; Cancer-rates; Occupational-exposure; Occupational-diseases; Respiratory-system-disorders; Lung-cancer; Risk-analysis;
Author Keywords: uranium miners; cohort mortality, radon progeny; lung cancer; pneumoconioses
Robert Roscoe, NIOSH, R-21, 4676 Columbia Parkway, Cincinnati, Ohio 45226