Further examination of employment in the chemical industry: follow-up case-control study of hematopoietic and lymphoid neoplasms using a next consecutive death control group

Occurrences of Leukemia Subtypes by Socioeconomic and Occupational Groups in Sweden

OBJECTIVE

The objective of this study was to examine the associations between socioeconomic/occupational factors and histologic subtypes of leukemia.

METHODS

The Swedish Family-Cancer Database was used to calculate standardized incidence ratios for different social classes and occupational groups.

RESULTS

The overall standardized incidence ratio was close to unity between different socioeconomic groups, except for female manual workers with a significantly decreased risk. Among male occupations, increased risks were noted for sales agents, seamen, and chemical process workers. For female occupations, increased risks were observed among mechanics, iron and metalware workers, hairdressers, and launderers and dry cleaners.

CONCLUSIONS

The present study suggests that socioeconomic/occupational factors have a minor effect on the risk of leukemia. Occupational groups with possible exposure to organic solvents and other chemicals such as chemical process workers, mechanics, iron and metalware workers, and launderers and dry cleaners may entail true risk for leukemia.

Occupational history and exposure and the risk of adult leukemia in Shanghai

PURPOSE

Evaluation of the association of selected occupational exposures with leukemia risk.

METHODS

Population-based case-control study of 486 leukemia subjects and 502 healthy controls residing in Shanghai from 1987 to 1989. Adjusted odds ratios (OR) were calculated for the association between occupational factors and leukemia risk.

RESULTS

Significant increase in leukemia risk was observed in chemical manufacturing industry workers (OR=3.1, 95% CI=1.0-9.8). Increased risks for leukemia were observed from self-reported exposures to benzene (OR=1.7, 95% CI=1.1-2.6), radioactive materials (OR=3.7, 95% CI=1.3-10.2), synthetic fiber dust (OR=2.0, 95% CI=1.2-3.5), and toluene (OR=1.6, 95% CI=1.0-2.5). Dose-response relations of leukemia risk was observed with the duration of exposure to benzene (OR=3.3, 95% CI=1.6-6.9 for >or=15 years exposure; p for trend<0.01), radioactive materials (OR=5.2, 95% CI=1.1-24.7 for >or=15 years exposure; p for trend=0.02), paints (OR=2.3, 95% CI=1.2-4.7 for >or=15 years exposure; p for trend=0.09), and toluene (OR=2.9, 95% CI=1.3-6.7 for >or=15 years exposure; p for trend=0.02).

CONCLUSIONS

Adult leukemia risk may be associated with working in the chemical industry, and exposure to benzene, synthetic fiber dust, radioactive materials, and toluene in the study population.