A retrospective cohort mortality study of males mining and milling attapulgite clay.
Waxweiler-RJ; Zumwalde-RD; Ness-GO; Brown-DP
Am J Ind Med 1988 Mar; 13(3):305-315
A retrospective cohort mortality study in miners exposed to attapulgite (1337764) was conducted. The cohort consisted of 2302 males, 1235 white, employed for at least 1 month between January 1, 1940 and December 31, 1975 at an attapulgite mining and milling facility (SIC-1459). Vital status of the cohort as of December 31, 1975 was determined. Death certificates of deceased subjects were obtained where possible. Standardized mortality ratios (SMRs) were calculated. Industrial hygiene monitoring data were reviewed. A total of 315 deaths were reported, for which 296 death certificates were obtained. The number of observed deaths was 80 percent of those expected. No significant excess mortality was seen for any cause. White subjects had almost a two fold excess risk of lung cancer mortality whereas nonwhites showed a 40 percent deficit. Mortality from nonmalignant respiratory disease (NMRD) was significantly decreased, with a SMR of 41. The deficit in NMRD mortality did not depend on length of employment or dust exposure. Lung cancer mortality was generally not dependent on dust exposure, induction or latency period, or length of employment except for subjects who had worked for at least 5 years in jobs having high dust exposures. The authors suggest that the lung cancer mortality may reflect cigarette smoking although no data on smoking were available. The authors recommend that in future studies of this cohort smoking data be collected.
NIOSH-Author; Epidemiology; Mortality-rates; Malignant-neoplasms; Lung-cancer; Occupational-exposure; Mining-industry; Mineral-dusts; Industrial-hygiene; Racial-factors;
Author Keywords: nonasbestos fibers; carcinogenicity; fibrogenicity; clay fibers
Dr. R. Waxweiler, Center for Environmental Health, Division of Injury Epidemiology and Control, Centers for Disease Control, Atlanta, GA 30333
American Journal of Industrial Medicine