Exposición crónica a plomo ambiental en lactantes chilenos II: efectos en el desarrollo psicomotor / Effects of chronic lead exposure on neurobehavioral development of Chilean lactating children

Background: Lactating children are specially susceptible to lead toxicity due to their underdeveloped nervous system, lower body mass, higher intestinal absorption and lower elimination rates. Aim: To determine the effects of lead exposure, comparing Chilean lactating children residing in rural areas with low lead exposure, and in urban areas with high lead exposure. Material and methods: Newborns from public maternity hospitals of the rural locality of San Felipe and from Metropolitan Santiago, were recruited for the study. On admission to the study, umbilical cord and maternal blood samples were obtained and an inquiry about perinatal, sociohereditary and lead exposure history was done. Children were followed every 6 months until 24 months of age, measuring blood parameters and neurobehavioral development using Bayley scales. Results: Three hundred twelve children from Santiago and 113 from San Felipe were studied. Maternal and children blood lead levels were higher in Santiago, but lower than those reported in other international studies. At 24 months of age, 4.5 percent of children from Santiago and 0.7 percent of children from San Felipe had levels over 10 µg/dl. No differences in neurobehavioral development were observed between children of both cities. At 24 months, scores of MDI scales were 91 in Santiago and 97 in San Felipe. The figures for PDI scale were 93 in Santiago and 93 in San Felipe. Main risk factors for a retarded neurobehavioral development were socioeconomic level with a mean Odds ratio of 3.5 (0.99-12.4), male sex with an Odds ratio of 2.3 (1.09-5.07) and stimulation at home with an Odds ratio of 0.7 (0.53-0.82. Conclusions: In this cohort of children, no effect of lead levels on neurobehavioral development was found

Exposición crónica a plomo ambiental en lactantes chilenos / 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 in this population. Aim: to measure blood lead levels in nursing infants, living in rural and urban areas, from birth until two years of age. Subjects 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 bird and venous blood samples thereafter, every 6 months until the age of 24 months. Lead levels were measured by atomic absorption spectrophotometry atmospheric lead was measured simultaneously every week in Santiago and the rural area. Results: three hundred twelve children from Santiago and 113 from the rural area completed the 24 months follow-up. The mean lead exposure for infants living in Santiago and in the rural area was 1.23 ñ 0.66 and 0.19 ñ 0.15 µg/m3 respective (p < 0.001). Mean blood levels were always higher in infants from Santiago, compared to those from the rural area. At 24 months, 4,5 percent of children from Santiago and 0,7 percent of children from the rural area had blood lead levels over 10 µg/dl. Significant risk factors for high lead levels were recent paining of the house where the infant lives, eating soil bitting banisters and familiar labor exposure to lead. Conclusions: infants living in an urban area and exposed to increased atmospheric lead levels have higher blood lead levels than infants living in a rural area