Measurement of vibratory perception threshold (VPT) in workers exposed to organic solvents.

Vibratory perception threshold (VPT) of 437 workers exposed to organic solvents in various industries was measured using an automated device, Vibrometer TM-31A, at the medial malleolus of the right leg. There were statistically significant correlations between age and VPT (rs = 0.378, P < 0.01) and job experience and VPT (rs = 0.125, P < 0.01). Fifty-five out of 437 examinees showed abnormally higher VPT than the previously reported control values, suggesting an existence of potential neuropathy in these individuals. There was no significant correlation between the amount of urinary metabolites and VPT. Neither specific exposure-related subjective symptoms nor clinical neurological signs were found in any workers. The study also discusses the validity of and the future problems in measuring VPT in workers exposed to solvents.