Health effects in children aged 3-6 years induced by environmental lead exposure

摘要

Objectives: To investigate the involvement of oxidative damage in lead-induced toxicity in children aged 3-6 years and to enlighten whether oxidative stress indicators are correlated with the known indices of lead toxicity. Methods: Blood samples were collected from 408 subjects (217 boys and 191 girls) in the urban kindergartens. The age range of the subjects was 3-6 years. Blood lead levels (BLLs) were analyzed by flameless atomic absorption spectrophotometry. Activities of 8-aminolevulinic acid dehydratase (ALAD), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and contents of glutathione (GSH) in erythrocyte and levels of plasma malondialdehyde (MDA) were analyzed spectrophotometrically in these children. Results: Children with BLLs > or = 100 μg/L had significantly decreased erythrocyte ALAD activities and increased plasma MDA levels compared to the children with BLLs < 100 μg/L. No significant changes were observed in erythrocyte SOD and GSH-Px activities and GSH levels associated with elevated BLLs in these children. Conclusion: Present data indicate that oxidative damage could be induced by lead in children with BLLs > or = 100 μg/L, and this may partly be attributed to the inhibited ALAD activities. Statistically significant changes of oxidative stress parameters in preschool children while BLLs were more than 100 μg/L could be implicated that oxidative damage might contribute to lead-induced intellectual impairment.