Peripheral nerve conduction study in workers exposed to a mixture of organic solvents in paint and lacquer industry.

Aim: To compare levels of combined exposure to white spirit, toluene, butyl acetate, ethyl acetate, and xylene in the manufacturing of paint, cartridge, drying, and top-coat sections of paint and lacquer industry, and peripheral nerve conduction parameters in the exposed workers.

Methods: The exposed group comprised 120 workers while the control group included 110 workers who had never been exposed to the above listed organic solvents. Nerve conduction studies of the radial and tibial anterior nerve were performed in both groups.

Results: Motor and sensitive conduction velocity, as well as terminal latency of the radial and tibial anterior nerve showed significant changes in exposed workers in comparison to those of the control group (p<0.001). These parameters were significantly changed in workers with long length exposure to the toxic agents. In early stages of exposure, neural conduction parameters of the radial nerve were the most sensitive parameters in detecting subclinical peripheral nerve changes (p<0.001). There was significant correlation between the nerve conduction changes and urinary levels of hippuric and methyl-hippuric acids (p<0.01).

Conclusion: The results of the study suggest neurotoxic effects of the mixture of white spirit, toluene, butyl acetate, ethyl acetate, and xylene detected in paint and lacquer industry. Standard measurement of the urinary levels of hippuric and methyl-hippuric acids could be a useful indicator of need for nerve conduction studies and the subclinical peripheral neuropathy screening in exposed workers.