Neurotoxicity of long-term low-level exposure to carbon disulphide: results of questionnaire, clinical neurological examination and neuropsychological testing

Abstract

Objective: Carbon disulphide (CS2) is highly neurotoxic. There is ample evidence of damage to the peripheral and central nervous system. The air concentration at which such adverse effects can first be observed is presently a subject of controversy.

Methods: In a cross-sectional study of CS2-exposed workers from the viscose industry and healthy controls, data on neurological complaints, basic laboratory diagnosis, clinical neurological examination and neuropsychological testing were evaluated. Data were from 222 workers in the viscose industry exposed to CS2 and 191 employees from the same factory with similar physical and psychological stress factors but without occupational contact with neurotoxic substances. Multiple linear or multiple logistic regression analysis was used to check for statistical differences.

Results: The median of the CS2-measurements using personal air sampling was below the current maximum concentration permissible (MAK value) in Germany (10 ppm) in all departments. The threshold limit value was, however, exceeded in almost 10% of the persons investigated. Exposure fluctuated between < 0.2 and 65.7 ppm (median of all departments was 4.02 ppm). As a parameter of internal exposure, CS2-metabolite 2-thio-1,3-thiazolidine-4-carboxylic acid (TTCA) concentrations in the urine of the exposed persons were between < 0.16 and 10.9 mg/g creatinine (median 1.43 mg/g).

Conclusions: Neither an increase in subjective complaints nor an increase in pathological findings in clinical-neurological and neuropsychological examination could be found in persons exposed to CS2 at the exposure levels described.