CHRONIC EXPOSURE TO ENVIRONMENTAL LEAD IN CHILEAN NURSING INFANTS

Background: In Chile, there are several sources of environmental lead exposure. However the few studies about lead levels in Chilean infants , do not allow to establish the prevalence of high lead levels in this population. Aim: To measure blood lead levels in nursing infants, liv ing in rural and urban areas, from birth until two years of age. Subje cts and methods: Newborns from public maternity hospitals in Santiago and a rural area were selected for the study. An umbilical cord blood sample was obtained at birth and venous blood samples thereafter, ever y 6 months until the age of 24 months. Lead levels were measured by at omic absorption spectrophotometry. Atmospheric lead was measured simul taneously every week in Santiago and the rural area. Results: Three hu ndred twelve children from Santiago and 113 from the rural area comple ted the 24 months follow-up. The mean lead exposure for infants living in Santiago and in the rural area was 1.23 +/- 0.66 and 0.15 +/- 0.15 mu g/m3 respectively (P < 0.001). Mean blood levels were always highe r in infants from Santiago, compared to those from the rural area. At 24 months, 4.5% of children from Santiago and 0.7% of children from th e rural area had blood lend levels over 10 mu g/dl. Significant risk f actors for high lead levels were recent painting of the house where th e infant lives, eating soil, biting banisters and familiar labor expos ure to lead. Conclusions: Infants living in an urban area and exposed to increased atmospheric lead levels have higher blood lead levels tha n infants living in a rural area.