Jacobson J L, Jacobson S W
Department of Psychology, Wayne State University, Detroit, MI 48202, USA.
N Engl J Med. 1996 Sep 12;335(11):783-9. doi: 10.1056/NEJM199609123351104.
In utero exposure to polychlorinated biphenyls, a ubiquitous environmental contaminant, has been linked to adverse effects on neurologic and intellectual function in infants and young children. We assessed whether these effects persist through school age and examined their importance in the acquisition of reading and arithmetic skills.
We tested 212 children, recruited as newborns to overrepresent infants born to women who had eaten Lake Michigan fish contaminated with polychlorinated biphenyls. A battery of IQ and achievement tests was administered when the children were 11 years of age. Concentrations of polychlorinated biphenyls in maternal serum and milk at delivery were slightly higher than in the general population. A composite measure of prenatal exposure was derived from concentrations in umbilical-cord serum and maternal serum and milk.
Prenatal exposure to polychlorinated biphenyls was associated with lower full-scale and verbal IQ scores after control for potential confounding variables such as socioeconomic status (P = 0.02). The strongest effects related to memory and attention. The most highly exposed children were three times as likely to have low average IQ scores (P <0.001) and twice as likely to be at least two years behind in reading comprehension (P = 0.03). Although larger quantities of polychlorinated biphenyls are transferred by breast-feeding than in utero, there were deficits only in associated with transplacental exposure, suggesting that the developing fetal brain is particularly sensitive to these compounds.
In utero exposure to polychlorinated biphenyls in concentrations slightly higher than those in the general population can have a long-term impact on intellectual function.
子宫内暴露于多氯联苯（一种普遍存在的环境污染物）已被证明与婴幼儿的神经和智力功能的不良影响有关。我们评估了这些影响是否会持续到学龄期，并研究了它们在阅读和算术技能习得中的重要性。
我们测试了212名儿童，这些儿童是作为新生儿招募的，以过度代表食用了受多氯联苯污染的密歇根湖鱼类的妇女所生的婴儿。当这些儿童11岁时，进行了一系列智商和成绩测试。分娩时母体血清和乳汁中多氯联苯的浓度略高于一般人群。产前暴露的综合测量值来自脐带血清、母体血清和乳汁中的浓度。
在控制了社会经济地位等潜在混杂变量后，产前暴露于多氯联苯与较低的全量表和语言智商得分相关（P = 0.02）。最强的影响与记忆和注意力有关。暴露程度最高的儿童平均智商得分低的可能性是其他儿童的三倍（P <0.001），阅读理解至少落后两年的可能性是其他儿童的两倍（P = 0.03）。尽管通过母乳喂养转移的多氯联苯量比子宫内暴露的多，但仅与经胎盘暴露相关存在缺陷，这表明发育中的胎儿大脑对这些化合物特别敏感。
子宫内暴露于浓度略高于一般人群的多氯联苯会对智力功能产生长期影响。
