Assessment of exposure to carbon disulfide in viscose production workers from urinary 2‐thiothiazolidine‐4‐carboxylic acid determinations

The follow‐up of environmental carbon disulfide (CS 2 ) exposure and urinary excretion of 2‐thiothiazolidine‐4‐carboxylic acid (TTCA) among 20 operatives over a 4‐day working week in two viscose producing factories confirmed earlier observations that TTCA is a sensitive and reliable indicator of exposure to CS 2 . Exposure to as low as 0.5–1.0 ppm (1.6–3.2 mg/m 3 ) of CS 2 (8‐hour time‐weighted average [TWA]) was associated with detectable amounts of TTCA in end‐of‐shift urine. Moreover, the excretion of TTCA, relative to estimated CS 2 uptake, appeared surprisingly constant in the studied work force. Approximately 3% (range 2–6.5%) of absorbed CS 2 was detected in urine as TTCA. The proportional TTCA excretion did not show dose dependency in the estimated CS 2 dose range which varied by about 20‐fold. TTCA elimination exhibited both a fast (T 1/2 6 hour) and a slow (T 1/2 68 hour) phase. The slow elimination is compatible with a high lipid solubility and reversible protein binding of CS 2 . Consequently, urinary excretion of TTCA, relative to CS 2 exposure, increased by about a third during the workweek. Urinary TTCA concentration of 4.5 mmol/mol creatinine in a postshift sample corresponded to a TWA exposure to 10 ppm CS 2 towards the end of the working week. © 1992 Wiley‐Liss, Inc.