CARBON-DISULFIDE .2. INVESTIGATIONS ON THE UPTAKE OF CS2 AND THE EXCRETION OF ITS METABOLITE 2-THIOTHIAZOLIDINE-4-CARBOXYLIC ACID AFTER OCCUPATIONAL EXPOSURE

The reported investigations on the uptake of carbon disulphide (CS2) a nd the excretion of its metabolite 2-thiothiazolidine-4-carboxylic aci d (TTCA) were based on results from 403 personal air samples (352 pass ive and 51 active samples) and 362 TTCA determinations in biological m aterial measured during a field study on the adverse effects due to CS 2 exposure. The external exposure ranged from below the detection limi t (0.2 ppm) to 66 ppm and the urinary TTCA excretion from below the de tection limit (0.16 mg./l) to 33.4 mg/l. The excretion of TTCA in post shift urine related to creatinine and volume showed a linear correlati on to the CS2 air concentration. On the basis of these results the inf luence on the internal exposure of physical work load, dermal exposure and individual parameters (age, Brocaindex, disturbed skin barrier) w as evaluated. Correlations between the TTCA values in the postshift ur ine and the individually measured CS2 concentrations were carried out separately for individual departments and persons with and without ind ications of a disturbed skin barrier. In order to be able to judge the individual internal exposure related to external exposure, a personal quotient was formed from the TTCA level in the urine and the CS2 air concentration measured on the same day (relative interal exposure RIE index = TTCA mg/g creatinine/CS2 in ppm). On investigating interindivi dual differences, higher relative internal exposures were found in per sons with a heavy physical work load and more intensive skin contact. It could be shown for a large group of persons exposed to CS2 that a p athological skin condition leads to an increase in the dermal penetrat ion rate of hazardous substances. By means of the RIE index it could b e shown that the TTCA excretion related to the individual external exp osure increases significantly with a decreasing Broca index, which mus t be taken into consideration with greatly overweight persons and expo sures in the range of the currently valid threshold limit values. The interindividual differences in internal exposure found at the same amb ient air concentration emphasize the importance of biological monitori ng for individual health protection and the setting of biological thre shold limit values.