Study on health effect of environmental lead exposure in children

Objective To explore the health impairments of environmental lead exposure in children of 6-12 years old.Methods Stratified random sampling was used.Questionnaire survey,physical examinations and intelligence examinations with Ravens' Standard Progressive Matrices were carried out among the children selected.Simplified Conners' Rating Scales(for teachers)was applied to assess the childrens' behavior.Blood and urine samples of the children were collected to determine the blood lead levels(BLLs),zinc protoporphyrin(ZPP)concentrations,δ-am inolevulinic acid dehydratase (ALAD)activities and urine δ-am ino-γ-levulinic acid(ALA)content.Results The geometric means of the children's BLLs,ZPP and ALA contents and ALAD activities was 71.2 μg/L,0.15 μg/g·Hb and 24.4 μg/L and 328.9 U,respectively.Fifty four(17.5%)children had BLLs ≥100 μg/L.The ZPP concentrations correlated with BLLs negatively as BLL s<100 μg/L,while positively as≥100 μg/L.The ALAD activities correlated with BLL spositively.Compared to children with BLLs<100 μg/L,children with BLLs ≥100 μg/L showed a decreased mimunity,lower intelligence and height,as well as behavioral changes.Conclusion Lead exposure is correlated with decreased heights,mimunity and in telligence,as well as behavioral changes among exposed chidren.