Assessment of neurobehavioral performance as a function of current and cumulative occupational lead exposure

A cross sectional Field study was planned to assess neurotoxic effects caus ed by low-level occupational lead exposure. Two groups of 66 workers and 86 controls were examined with a battery including a questionnaire on neuroto xic symptoms, the measure of performance at neurobehavioral testing, the de tection of visual contrast sensibility, and the dosage of serum prolactin. Both current and cumulative exposure to lead were defined The average PbB w as 27.50 +/- 28 mug/dl (median 28, range 6-61) in the exposed and 8.11 +/- 4.47 mug/dl (median 7, range 2-21). The test results were controlled for po ssible confounders including age, schooling, alcohol and coffee intake. Sig nificant differences were observed between exposed and controls regarding n eurotoxic symptoms reporting, the exposed reporting more frequently mood ch anges and abnormal fatigue. The exposed subjects showed a decreased visual contrast sensitivity, and a marked increase of prolactin secretion. No chan ges emerged regarding neurobehavioral testing. The alterations observed res ulted associated to the current lead exposure and not to the cumulative ind ices. A safe exposure level was calculated on the basis of dose-response re lationship with prolactin alteration, yielding a PbB value of 10 mug/dl. (C ) 2000 Inter Press, Inc.