ENVIRONMENTAL EXPOSURE TO LEAD AND CHILDRENS INTELLIGENCE AT THE AGE OF 7 YEARS - THE PORT-PIRIE COHORT STUDY
ENVIRONMENTAL EXPOSURE TO LEAD AND CHILDRENS INTELLIGENCE AT THE AGE OF 7 YEARS - THE PORT-PIRIE COHORT STUDY
复制标题
DOI：
10.1056/nejm199210293271805
复制
发表时间：
1992-10-29
影响因子：
158.5
通讯作者：
TONG, SL
中科院分区：
文献类型：
--
作者：
BAGHURST, PA;MCMICHAEL, AJ;TONG, SL
背景。人们认为，儿童早期接触铅会导致神经心理发育迟缓。迄今为止，几乎没有纵向证据来确定这些影响是否持续到童年后期。方法。我们测量了来自澳大利亚皮里港铅冶炼社区的 494 名 7 岁儿童的智商分数，这些儿童在两岁和四岁时就已经报告了与血铅浓度升高相关的发育缺陷。铅暴露量是根据产前和分娩时抽取的母体血液样本中的铅浓度以及儿童出生时（脐带血）、6 个月、15 个月和 2 岁时以及此后每年抽取的血液样本中的铅浓度估算的。针对每个儿童在生命的前七年系统地收集了与儿童发育的已知协变量相关的数据。结果。我们发现七岁时的智商与产前和产后血铅浓度呈负相关。在对性别、父母受教育程度、产妇分娩年龄、父母吸烟状况、社会经济状况、家庭环境质量、产妇智商、出生体重、出生顺序、喂养方式（母乳、奶瓶或两者兼有）、母乳喂养持续时间以及孩子的亲生父母是否同居进行多元回归调整后，出生后血液样本中铅暴露的关系仍然很明显，特别是在15个月至4岁的年龄范围内。如果血铅浓度从 10 杯每分升（0.48 微摩尔每升）增加到 30 杯每分升（1.45 微摩尔每升）（以 15 个月以及 2、3 和 4 岁时的浓度平均值表示），儿童智商的估计下降范围为 4.4 分（95% 置信区间，2.2 至 6.6）至 5.3 分（95% 置信区间，2.8 至 7.8）。这种下降代表智商大约下降了 4% 到 5%。结论。儿童早期接触低水平的铅与生命前七年的神经心理发育呈负相关。
Background. Exposure to lead in early childhood is thought to result in delayed neuropsychological development. As yet there is little longitudinal evidence to establish whether these effects persist into later childhood.Methods. We measured IQ scores in 494 seven-year-old children from the lead-smelting community of Port Pirie, Australia, in whom developmental deficits associated with elevated blood lead concentrations had already been reported at the ages of two and four years. Exposure to lead was estimated from the lead concentrations in maternal blood samples drawn antenatally and at delivery and from blood samples drawn from the children at birth (umbilical-cord blood), at the ages of 6 and 15 months and 2 years, and annually thereafter. Data relating to known covariates of child development were collected systematically for each child throughout the first seven years of life.Results. We found inverse relations between IQ at the age of seven years and both antenatal and postnatal blood lead concentrations. After adjustment by multiple regression for sex, parents' level of education, maternal age at delivery, parents' smoking status, socioeconomic status, quality of the home environment, maternal IQ, birth weight, birth order, feeding method (breast, bottle, or both), duration of breast-feeding, and whether the child's natural parents were living together, the relation with lead exposure was still evident for postnatal blood samples, particularly within the age range of 15 months to 4 years. For an increase in blood lead concentration from 10 mug per deciliter (0.48 mumol per liter) to 30 mug per deciliter (1.45 mumol per liter), expressed as the average of the concentrations at 15 months and 2, 3, and 4 years, the estimated reduction in the IQ of the children was in the range of 4.4 points (95 percent confidence interval, 2.2 to 6.6) to 5.3 points (95 percent confidence interval, 2.8 to 7.8). This reduction represents an approximate deficit in IQ of 4 to 5 percent.Conclusions. Low-level exposure to lead during early childhood is inversely associated with neuropsychological development through the first seven years of life.