Decreases in postural change of finger blood flow in ceramic painters chronically exposed to low level lead

To elucidate the effect of low level lead (Pb) exposure on somatic and autonomic peripheral nerve functions in ceramic painters, 58 males and 70 females, aged 29-75 years (mean 53.3 years), with lead concentrations in blood (Pb-B) ranging from 2.1 to 69.5 micrograms/dl (geometric mean 13.3 micrograms/dl), were examined for median nerve maximal conduction velocity as a measure of motor nerve function, the coefficient of variation of R-R interval on electrocardiography as a measure of parasympathetic function, and postural changes in finger blood flow volume (delta FBF), and changes in finger blood flow drop velocity (FDV) from the supine to standing position as a measure of sympathetic function. No significant association was found between Pb-B levels and the results of the neurophysiological tests, however, except for that between Pb-B and delta FBF was decreased linearly with increasing Pb-B levels. However, this association could not be concluded to be a reflection of sympathetic nerve dysfunction due to Pb exposure in the subjects, since delta FBF was not a specific parameter of sympathetic nerve function. The possibility that the decrease in delta FBF is a reflection of the atherosclerotic effect of chronic low level Pb exposure should be further investigated.