Neurotoxicity of solvent mixtures in spray painters. I. Study design, workplace exposure, and questionnaire

A multidisciplinary cross-sectional study was carried out in 105 spray painters with long-term solvent exposure (10-44 years) and in 58 control subjects not exposed to solvents. By means of air monitoring the solvent concentrations in the ambient air during spray painting were determined using charcoal and silicagel tubes with pumps and passive samplers. In general, the air concentrations of the individual compounds did not exceed the current limit values (MAK values). Aromatic hydrocarbons like toluene, xylene, ethylbenzene, trimethylbenzene, aliphatic hydrocarbons (e.g., heptane) and acetates (ethylacetate, butylacetate) were determined to be important components of paint solvents. However, in unfavorable work conditions the "exposure index" could exceed the permissible limits two or three times. To assess the body solvent load at the time of examination, biological monitoring (BM) was performed. The main finding was that there was no evidence of neurotoxicologically relevant solvent exposure. Only in the case of methyl hippuric acid in urine spot samples did the spray painters show a higher mean value (80 mg/l) than control subjects (below 20 mg/l), indicating recent xylene exposure. Elevated urinary chromium concentrations (maximum value 29 micrograms/l) were found in 28 spray painters as a result of using zinc chromate-containing wash primers without taking protective measures. To assess the degree of past solvent exposure a special questionnaire was used. This included variables like duration and amount of solvent exposure, the presence of a technical ventilation system, health complaints during painting, etc. Additionally, three "solvent exposure indices'' (SEI) were calculated and used for evaluation of "dose-effect relationships.''(ABSTRACT TRUNCATED AT 250 WORDS)