[Subclinical neuropathy in workers occupationally exposed to n-hexane]

ABSTRACT

N-Hexane is widely used in the production of glues, lacquers, paints, plastics, and rubber products. Consequently, a significant potential for exposure to this toxic solvent exists in industrial settings. This study was undertaken to assess the neurophysiological abnormalities in shoe-makers occupationally exposed to n-hexane and determine whether these abnormalities have any correlation with important occupational parameters. Neurophysiological examinations of upper and lower extremities were made in 27 male-workers, and the results were compared with a sex- and age-matched reference group. In addition, the extent of exposure of individual workers and their urinary concentration of free 2,5-hexanedione were determined. Data were analyzed using the Statistical Package for Social Sciences [version 16.0. for windows]. The time-weighted average exposure to n-hexane and the mean urinary concentration of free 2,5-hexanedione were both lower than the respective TLV-TWA and Biological Exposure Index [BEI] values proposed by ACGIH. Although neurological examinations and nerve conduction velocities were normal, significant negative correlations were observed between the urinary concentration of free 2,5-hexanedione and the sensory nerve action potential [SAP] amplitudes for median [r=-0.67, p<0.001] and sural [r=-0.52, p<0.008] nerves. Reduced SAP amplitude for median and sural nerves appears to be the primary neurotoxic effect of 2,5-hexanedione and can be used as an appropriate indicator for screening subclinical peripheral neuropathy in n-hexane-exposed workers