Mortality among maintenance employees potentially exposed to asbestos in a refinery and petrochemical plant.

This paper reports the mortality experience from 1948 to 1989 of 2,504 maintenance employees who had a minimum of one year of employment in jobs with potential exposure to asbestos at a Texas refinery and petrochemical plant. For the purposes of this study, "potential exposure" is equated with those jobs or crafts having the greatest direct potential proximity to, or which worked directly with, asbestos-containing materials, especially asbestos-containing thermal insulation. Approximately one-half of the study population had 10 years or longer potential exposure, and 80% had their first potential exposure before 1970. The total population exhibited significantly lower mortality for all causes, the standardized mortality ratio (SMR = 77); and for all cancer (SMR = 85), as compared to residents in the surrounding communities. Statistically significant deficits in mortality were also observed in a number of noncancerous diseases such as heart disease (SMR = 78; 95% CI = 69-88), nonmalignant respiratory disease (SMR = 70; 95% CI = 50-95), and cirrhosis of the liver (SMR = 44; 95% CI = 22-79). Mortality among employees who had 20 years or longer since their first potential exposure was also examined; the pattern of mortality was similar to that exhibited by the total cohort, with a slight increase in the SMR for most of the causes. The only statistically significant excess of mortality found was a fourfold increase in mesothelioma (5 observed and 1.2 expected deaths) the SMR was 428 (95% CI = 139-996) for the total cohort and was 469 (95% CI = 152-1093) for those who had 20 years or more since first potential exposure. In contrast to asbestos industry worker studies, mortality for lung cancer was substantially lower than the general population (SMR = 81; 95% CI = 63-103). The observed number of deaths for cancer of the larynx was virtually the same as expected (3 observed vs. 2.8 expected). This study also showed decreased mortality for cancers of gastrointestinal organs such as the esophagus (SMR = 78), stomach (SMR = 63), large intestine (SMR = 91), rectum (SMR = 55), or pancreas (SMR = 90)--cancers that have been reported to be elevated in studies of various industry workers directly exposed to asbestos.

Personal and job characteristics of musculoskeletal injuries in an industrial population.

A cross-sectional study was conducted of 10,350 full-time regular employees who worked at Shell Oil Company's manufacturing facilities between 1987 and 1989. Two hundred seventy-five employees with low-back and 456 with nonlow-back musculoskeletal injuries were compared with 8295 employees who did not have musculoskeletal injuries during this period. Based on morbidity data collected from a prospective health surveillance system, this study shows that estimated relative risks (RRs) for low-back injuries are significantly higher among smokers (RR = 1.54, P less than .01) and overweight persons (RR = 1.42, P less than .01). This observation is also true for nonlow-back musculoskeletal injury (RR = 1.23, P = .05 for smokers and RR = 1.53, P less than .01 for overweight persons). In addition, persons in potentially more physically demanding jobs (primarily maintenance job titles) had an increased RR for both low-back and nonlow-back musculoskeletal injuries (RR = 1.57, P less than .01 and RR = 1.35, P = .02, respectively). The findings of this study suggest that it may be possible to reduce the impact of musculoskeletal injury through implementation of an integrated injury prevention program. Such programs would include not only the traditional elements of job factors evaluation and modifications, employee education and training, and an overall increased attention to ergonomics but also medical counseling and support for personal fitness programs, workplace smoking cessation programs, and weight-reduction programs.