BACKGROUND Organohalogen compounds (OHCs), i.e. polychlorinated biphenyls (PCBs, are wide-spread environmental pollutants known to be neurotoxic for the developing brain. The hydroxylated metabolites of PCBs, OH-PCBs, might be even more toxic due to their structure and interference with thyroid hormone metabolism. We found that prenatal exposure to OH-PCBs was associated with thyroid hormone metabolism at toddler age. Little, however, is known about the neurotoxicity of OH-PCBs in humans. OBJECTIVES To determine whether prenatal background exposure to OHCs has an effect on mental and motor development in children at the age of 18 and 30 months. METHODS One hundred and eighty-one healthy mother-infant pairs were included in this observational study performed in the Netherlands. We measured maternal pregnancy levels of PCB-153 and three OH-PCBs. In one part of the cohort we measured another nine PCBs and three OH-PCBs and in the other part we measured five brominated diphenyl ethers (BDEs), dichloro-diphenyldichloroethylene (p,p'-DDE), pentachlorophenol (PCP), and hexabromocyclododecane (HBCDD). We used the mental development index (MDI) and the motor development index (PDI) of the Bayley Scales of Infant Development II (BSID-II) to assess children's mental and motor development (mean = 100; delayed score <85). RESULTS Higher prenatal PCB-153 levels were associated with a delayed MDI score at 18 months. None of the other compounds were associated with a delayed score, but several associations were found between OHC levels and BSID-II scores. The sum of all six OH-PCBs and three individual OH-PCBs, 4-OH-PCB-107, 3-OH-PCB-153, and 4'-OH-PCB-172, correlated positively with MDI at 30 months. The compound 3'-OH-PCB-138 showed a similar trend. A higher 4-OH-PCB-187 was associated with a lower MDI at 18 months. We found a similar trend for higher BDE-99. Higher BDE levels were associated with higher PDI at 18 months. The levels of p,p'-DDE-, PCP, and HBCDD were not associated with BSID-II scores at 18 months. CONCLUSIONS Higher prenatal levels of PCB-153 were associated with a delayed MDI score at 18 months. None of the other compounds were associated with a delayed score, but several associations were found between OHC levels and BSID-II scores. Prenatal OH-PCBs were positively associated with mental development at 30 months, whereas one OH-PCB was negatively associated at 18 months. BDE levels were positively associated with psychomotor development. Prenatal p,p'-DDE, PCP, and HBCDD levels were not associated with neurodevelopment at 18 months.

中文翻译：

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产前暴露于有机卤素化合物，以及18和30个月大的儿童的智力和运动发育。

在该队列的一部分中，我们测量了另外九个PCB和三个OH-PCB，在另一部分中，我们测量了五个溴化二苯醚（BDE），二氯-二苯基二氯乙烯（p，p'-DDE），五氯苯酚（PCP）和六溴环十二烷（六溴环十二烷）。我们使用贝利婴儿发育量表II（BSID-II）的智力发育指数（MDI）和运动发育指数（PDI）评估儿童的智力和运动发育（平均值= 100；延迟评分<85）。结果较高的产前PCB-153水平与18个月时MDI评分延迟有关。其他化合物均未与延迟评分相关，但在OHC水平和BSID-II评分之间发现了几种相关性。所有六个OH-PCB和三个单独的OH-PCB，4-OH-PCB-107、3-OH-PCB-153和4'-OH-PCB-172的总和，在30个月时与MDI呈正相关。化合物3'-OH-PCB-138显示出相似的趋势。18个月时，较高的4-OH-PCB-187与较低的MDI相关。对于更高的BDE-99，我们发现了类似的趋势。较高的BDE水平与18个月时的PDI较高相关。在18个月时，p，p'-DDE-，PCP和HBCDD的水平与BSID-II得分无关。结论产前较高的PCB-153水平与18个月时MDI评分延迟有关。其他化合物均未与延迟评分相关，但在OHC水平和BSID-II评分之间发现了几种相关性。产前OH-PCB在30个月时与精神发育呈正相关，而一种OH-PCB在18个月时与精神发育呈负相关。BDE水平与精神运动发育呈正相关。产前p，p'-DDE，PCP，