Effects of very low blood lead levels on neurobehavioral performances of male policemen in kota bharu, kelantan.

Many published studies that examined the effect of lead exposure on neurobehavioral performances were conducted in confined manufacturing environment with low to moderate blood lead levels as a marker of exposure. This study was conducted in a general environmental setting with very low exposure intensity and blood lead levels. The objective of the study was to determine the effect of very low blood lead levels (below 10 μg/dl) on the neurobehavioral performances of policemen in Kota Bharu, Kelantan. The study, conducted between August 25(th) and October 20(th) 2001, was cross-sectional in design and comprised of 89 policemen working in Kota Bharu district. The lead concentration of venous blood was determined using graphite furnace absorption spectrometer. We assessed neurobehavioral performances using the WHO Neurobehavioral Core Test Battery (NCTB). The mean blood lead concentration was 2.5 + 1.0 mg/dl. Among the seven tests performed, the positive effect of blood lead on Benton visual retention was not significant after controlling for the confounding effect of smoke-dose. This study suggested that very low blood lead levels have no significant effects on the neurobehavioral performances. Therefore, more studies with blood lead levels below the recommended environmental limit of 10 mg/dl, as recommended by Centers for Disease Control (CDC), be conducted in order to justify that limit.