Correlation of blood lead level and intelligence quotient in children

Abstract

Background Lead poisoning is a source of health problems in humans. A chronic complication oflead poisoning in children is permanent intellectual impairment. Objective To assess for a correlation of blood lead levels and intelligence quotient (IQ) in children. Methods A cross-sectional study was performed in children aged 6 to 8 years in th e Talawaan (a rural area) and Wenang (an urban area) Distticts, North Sulawesi, from April to July 2012. Blood lead levels were measured using the graphite furnace atomic absorption spectrometry technique; and intelligence was meas ured with the Wechsler Intelligence Scale for Children-Indonesian version. Results There were 50 subjects from the Talawaan District and 54 subjects from the Wenang Disttict in this study. The mean blood lead level in the Talawaan District subjects was significantly higher than that of the Wenang Disttict subjects [25.8 (SD 16.98) μgidL vs 11.4 (SD 13.81) μgidL, respectively; (P<0.001)]. There was a weak negative correlation between blood lead level and IQ in the Talawaan Disttict children (P= 0.038; r= -0.3). As such, there was a 0.05 IQ point decrement associated with each increase of 1 μ gidL in blood lead level in Talawaan District children. However, there was no correlation between blood lead level and IQ in the Wenang Disttict children (P=0.42; r =0.03). Conclusion There is a weak negative correlation between blood lead level and IQ in children living in a rural area, howevei; this correlation is not found in children living in an urban area.

Keywords

• lead, IQ, children