Critical review of the epidemiological literature on the potential cardiovascular effects of occupational carbon disulfide exposure.

OBJECTIVES

Occupational carbon disulfide (CS(2)) exposure has been associated with a variety of health effects since its introduction in the mid-19th century. Much of the epidemiological interest, especially since the 1960s, has focused on associations with cardiac effects. However, considerable differences in study approach, disease outcome, CS(2) exposure level, and control of confounding factors have produced mixed results and conclusions. This critical review presents a synthesis of the most relevant and best quality studies to better understand these associations.

METHODS

Using specific criteria to assess methodological and scientific quality, we identified 37 studies with the potential to inform on at least one of the following questions: (1) Has a relationship between CS(2) exposure and coronary heart disease (CHD) mortality been reasonably demonstrated? If so, at what apparent exposure levels has it been observed? (2) Among studies of workers routinely exposed to CS(2) at levels greater than 20 ppm, have any health effects or indicators of CHD been observed consistently? (3) Among occupational groups exposed to CS(2) at levels less than 20 ppm, have any health effects or indicators of CHD been observed consistently?

RESULTS

Several CHD-related effects have been examined relative to various levels of occupational CS(2) exposure. Overall, there was remarkably little consistency of CHD effects observed, including CHD mortality.

CONCLUSIONS

Although a physiological effect of CS(2) exposure on CHD is plausible, the epidemiological evidence for an association between CS(2) exposure and various cardiac risk indicators is mixed. The only somewhat consistent finding, of CS(2) exposure on total and/or LDL cholesterol level, may be due to residual confounding by other time-dependent risk factors. If real, however, it appears to be of small magnitude and uncertain clinical importance.