title: Biological monitoring of carbon disulphide: kinetics of urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) in exposed workers.
abstract: The objectives of this study was to establish the kinetics of urinary 2-thiothiazolidine-4-carboxylic acid (U-TTCA) for workers exposed to carbon disulphide (CS2) and to investigate the effects of volume and creatinine adjustment methods for urine measurement. Ten workers in the spinning department of a rayon factory were individually monitored for airborne CS2 concentrations, with consecutive urine samples collected for 24-38 hours after termination of exposure. The U-TTCA, urine volume and creatinine level were measured for each sample. First-order and biphasic kinetics were determined using the curve-fit method, for the measurement series. For the first-order kinetics linearity fit, statistically significant correlation coefficients of 0.74-0.98 and 0.86-0.99 were derived for the volume- and creatinine-adjusted methods, respectively. For the biphasic kinetics approach, the overall correlation coefficients were 0.544-0.999 and 0.171-0.999 for the first and second phases of the creatinine-adjusted method, respectively. A post-shift U-TTCA of 3.0 mg/g Cr. equivalent, 40% below the current BEI setting at nearly PEL exposed level, was found. In conclusion, first-order kinetic response was confirmed for U-ITCA. Both volume- and creatinine-based urine adjustment are satisfactory for TTCA assessment as a biomarker of individual CS2 exposure although the correlation for creatinine-based measurement was modestly superior to the volume-based analogue. Based on the results of this study,we recommend a re-evaluation of the current biological exposure index of 5 mg/g creatinine at a CS2 exposure level of 10 ppm.
authors.affiliation: Graduate Institute of Environmental and Occupational Health, National Cheng Kung University Medical College, 138 Sheng-Li Rd. 70428, Tainan, Taiwan, Republic of China.
authors.forename: Ho-Yuan
authors.initials: HY
authors.lastname: Chang
authors.forename: Tzu-Chieh
authors.initials: TC
authors.lastname: Chou
authors.forename: Peng-Yau
authors.initials: PY
authors.lastname: Wang
authors.forename: Tung-Sheng
authors.initials: TS
authors.lastname: Shih
mesh_terms: D000328:Adult; D002246:Carbon Disulfide / Q000493:pharmacokinetics*; D002617:Chemical Industry; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000652:urine; D004784:Environmental Monitoring; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D013844:Thiazoles / Q000652:urine*; D053778:Thiazolidines
chemical_list: D013844:Thiazoles; D053778:Thiazolidines; C031677:2-thioxo-4-thiazolidinecarboxylic acid; D003404:Creatinine; D002246:Carbon Disulfide