Effects of blood lead concentration on intelligence and personality in school children

This study was conducted to evaluate the effects of lead concentration in the blood on intelligence and personality in school children in Korea. This study was designed as a cross sectional study. The Korean Intelligence Test-Primary was administered to the 302 school age children (154 3rd-grade and 155 6th-grade) of three areas, urban, fishery, and agricultural area, Korea. Blood lead (Pb-B) was measured by means of atomic absorption spectroscopy equipped with graphite furnace atomizer. Geometric means of Pb-B for boys and girls were 2.79 +/- 1.58 mu g/dL and 2.54 +/- 1.51 mu g/dL, respectively. No children exceeded Pb-B of 10 mu g/dL that is the recommended level of Pb-B in children by CDC, U.S.A. When the subjects were classified by median into two groups, upper and lower Pb-B groups, the IQ of upper and lower groups were 106.4 +/- 13.7 and 110.0 +/- 14.9 respectively. IQ score of upper group was lowered about 4 points than that of lower group. We founded that hyperactivity and autism score of Pb-B groups was higher than that of lower group. These results are coincident with the large-scale study results developed countries that chronic exposure to lead may reduce the intelligence of child. This study may provide the first suggestive evidence that Pb-B has an impact on childhood intelligence and personality in Korean children. It is necessary to consider the effects of other important factors, such as parental intelligence in the next study.