RESUMO
OBJECTIVE: To explore the effects of low-level lead exposure on infant's neurobehavioral development and evaluate the effects of early intervention. METHODS: The study population consisted of 276 infants whose blood lead, cadmium, iron, zinc, copper, magnesium and calcium concentrations were measured by atomic absorption spectroscopy and developmental status were assessed using the Gesell developmental Diagnosis scales (GDDS) at 6 months of age. All study subjects was divided into three groups: 58 infants in control group, 162 infants in low lead group and 56 infants in high lead group. On the basis infants of both the low and high lead groups were provided with interventional measures for 3 months, and tests for the blood lead, cadmium, iron, zinc, copper, magnesium, calcium and GDDS were repeated for all infants both 12 and 18 months of ages. RESULTS: Infant' s developmental outcome revealed the developmental quotient was the lowest in the high lead group (86.74 +/- 9. 35), the lesser low in the low lead group (91.52 +/- 10.12) and the highest in control group (100.71 +/- 6.92). Changes in developmental quotient were detected in both the low and high lead groups with statistical significance (P < 0.05) after intervention measures adopted. However, the changes of developmental quotient were more remarkable in the low lead group and after the 18th month there was no statistical significance than control group (t = 1.721, P > 0.05) while the significant difference was found in between the high lead group and the control group (t = 23.495, P < 0.05). CONCLUSION: Low-level lead exposure interfered infant's neurobehavioral development and early intervention might improve infant's developmental quotient.