[Relationship between vibratory sense threshold and blood lead concentration in ceramic color workers and transfer...

We measured vibratory sense thresholds (VSTs) at 63Hz and 125Hz on the third fingertip of the right hand and on the third toe of the right foot of 74 male workers. The subjects were workers engaged in manufacturing ceramic color and transfer printing paper, whose blood lead (Pb-B) levels were 2-58 micrograms/dl. They were divided into three groups according to the Pb-B levels, namely, below 9, 10-19, and 20 micrograms/dl or more. For statistical analysis, simple and partial correlations, and Scheffé's multiple comparison between the least squares means were used. The VSTs on the fingertip as well as on the toe showed a significant correlation with age. The VSTs at 125Hz on the fingertip were also significantly correlated with alcohol consumption and cigarette smoking. Controlling for age, systolic blood pressure, alcohol consumption and smoking habit, a significant dose-effect relationship was observed between the VSTs at not only 63Hz but at 125Hz on the fingertip, and each of the corresponding Pb-B levels. A similar tendency was also observed at the two frequencies on the toe. The measurement of VSTs was considered to be an effective screening test for sensory nerve disorders caused by lead poisoning.