Indicators of cardiovascular risk among workers exposed to high intermittent levels of carbon disulphide

The effects of exposure to carbon disulphide have been studied mostly among workers in the viscous rayon industry, where the usual exposure profile ha s been relatively steady exposure over work shifts. We investigated 13 work ers in a small chemical company who were exposed to low levels, peaking int ermittently to relatively high revels in the range of 100-200 ppm at the en d of the work shift, a pattern that may change the risk profile. Our invest igation was part of a compliance order that was fought by the company and o ur access and follow-up was limited. Two workers had burns on their bodies associated with exposure to caustic. Four had elevations in total serum cho lesterol, one had elevated serum triglycerides and three had elevations in fasting blood glucose - two of them were known to be diabetics before emplo yment and one had a history of unexplained peripheral neuropathy. No consis tent pattern suggestive of a defined lipoprotein abnormality was obvious bu t several atherogenic profiles were observed. Five had abnormalities on ele ctrocardiogram, four of whom appeared to be among the most heavily exposed. The presence of these changes taken together in this context may suggest a ccelerated atherosclerotic changes. Tests of liver and kidney function were within the normal range for all workers, as was a complete blood count. Fo ur of the workers had evidence of a bilateral reduction in hearing threshol d at 4,000 Hz. A complete set of recommendations was forwarded to the emplo yer, emphasizing further control of exposure to carbon disulphide, personal protection requirements and a cardiovascular risk reduction programme. Con ditions improved in the plant following modifications introduced in respons e to a stop work order from the provincial government's occupational health and safety agency. However, a fire in 1998 put the company out of business and ended further follow-up or interventions. We conclude that these findi ngs, while difficult to interpret because of the circumstances of the inves tigation, are compatible with an atherogenic effect of exposure to peaking levels of carbon disulphide. The observation should be tested in a larger p opulation with fewer confounding factors and greater control over the inves tigation.