Biological monitoring of carbon disulfide

The aim of this study was to investigate the relation between exposure to carbon disulfide, as measured by personal air sampling, and the excretion of 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine. The subjects of investigation were 29 workers involved in the production of viscose rayon fibers. The average exposure level was 12.6 mg/m3 (range less than 1-66). The present Dutch occupational exposure limit ("MAC-value") is 60 mg/m3. After logarithmic transformation of the data, the following linear regression equation was found: log (TTCA) = 0.84 log (CS2) - 1.10, wherein TTCA is expressed as mmol/mol creatinine and CS2 as mg/m3. The correlation coefficient was 0.95. Neither the hepatic drug-metabolizing capacity (antipyrine clearance) nor the degree of obesity (Quetelet index) influenced the relationship significantly. On basis of the equation it was possible to establish tentative biological limit values corresponding to the respective occupational exposure limit values. The calculated biological limit value of 0.77 mg/g creatinine (= 0.57 mmol/mol creatinine) corresponds, with 95% confidence, to time-weighted average of air concentration lower than the TLV level of 30 mg/m3.