Exposure to carbon disulphide (CS2) in a viscose plant was measured by personal monitoring and by application of the iodine azide test and quantification of 2-thio-thiazolidine-4-carboxylic-acid (TTCA) in urine samples. A relation was found between the rise in urinary ITCA concentration during the workshift and the exposure index E,. The correlation (r) between the exposure index and the atmospheric concentrations of CS2 in workroom air below 100 mg CS2/m3 was 059 (n = 9). The correlation between the increase in TICA concentrations during the workshift and the atmospheric CS2 concentrations was found to be higher when urine samples at the end of the workshift with creatinine concentrations below 1 mg/ml and above 3 mg/ml were disregarded (from r = 0-61; n = 20 to r = 0-84; n = 14). A high correlation was found (r = 0O86; n = 13) when the end of workshift urine samples were analysed, provided that their creatinine concentrations are not beyond the limits given above.The iodine azide test which is based on the fact that certain constituents in the urine of rabbits exposed to carbon disulphide catalyse the reaction between iodine and sodium azide, was developed by Vasak et al' to evaluate the degree to which workers are exposed to carbon disulphide. The chemical reaction may be written as: 2 NaN3 + I2 -. 3 N2 + 2 NalThe original method consisted of measuring the time needed for the disappearance of the yellowish brown colour of iodine on the addition of urine to the reaction medium. Vasak proposed an exposure index E in which E = C log t where E = exposure index, C = creatinine concentration in mg per ml unne, and t = discoloration time in seconds.Received 25 April 1983 Accepted 11 July 1983The reaction between sodium azide and iodine proceeds slowly at room temperature but is apparently catalysed by the addition of a number of organic and inorganic compounds. This is thought to be due to the formation of an intermediary addition compound of the catalysing agent with iodine or sodium azide, which will then react with sodium azide or iodine. respectively, forming nitrogen and iodide ions, and leaving the catalysing agents unchanged.2 The catalysing agents responsible for this reaction are most likely to be dithiocarbamate derivatives of amino acids and some other CS2 metabolites such as 2-mercaptothiazolinone-53 and thioureum,4 which when added in pure form to the iodine azide solution, discolours it immediately. Some sulphur containing compounds derived from drugs or the diet, however, also catalyse the reaction, thus giving false positive results. In addition, the main disadvantage of the method is that discoloration occurs gradually, and there is no specific point of discoloration. Because of the subjective element in the readings, different exposure indices could be determined when the urine sample is added to the reaction mixture.In 1981 Van Doorn discovered 2-thiothiazolidine-4-carboxylic-acid (TTCA) in the urine 412

The exposure to carbon disulfide of workers in charge of different jobs in a Belgian viscose plant was measured by means of personal monitoring of the inhaled air and by quantitative assay of 2-thio-thiazolidine-4-carboxylic acid (TTCA) in urine. It was found that the atmospheric carbon disulfide concentration varied considerably among different jobs, among different individuals doing the same jobs and for the same individuals in the course of the working period. The 2-thio-thiazolidine-4-carboxylic-acid levels increased markedly during the exposure. The correlation between individual personal monitoring results and the increase TTCA levels was found to be statistically significant.

No abstract

No abstract