This is a cross-sectional study with a randomized choice of individuals aiming at studying the validity of the Brazilian biological exposure limits applied to lead level in the blood (PbB) and delta-aminolevulinic acid in the urine (ALAU), which are 60 µg/dl and 10 mg/g.creat., respectively. For this purpose, twenty workers, whose PbB and ALAU values have been below these limits over the past two years, were selected at random at a battery production plant in the State of S. Paulo, Brazil. The workers were submitted to a peripheral nerve conduction study. The results were compared with those obtained for workers of a control group also chosen at random. The lead workers showed a decrease in the velocity conduction of the radial nerves. Comparing this group with a randomized control group, a significant difference was observed (p-value = 0.0067). The results suggest that the Brazilian biological exposure limits above should be rearranged.
Occupational exposure; Lead poisoning; Peripheral nervous system diseases