Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
Environ Int. 2017 Feb;99:321-330. doi: 10.1016/j.envint.2016.12.015. Epub 2016 Dec 29.
Depending on the chemical and the outcome, prenatal exposures to environmental chemicals can lead to adverse effects on the pregnancy and child development, especially if exposure occurs during early gestation. Instead of focusing on prenatal exposure to individual chemicals, more studies have taken into account that humans are exposed to multiple environmental chemicals on a daily basis. The objectives of this analysis were to identify the pattern of chemical mixtures to which women are exposed and to characterize women with elevated exposures to various mixtures. Statistical techniques were applied to 28 chemicals measured simultaneously in the first trimester and socio-demographic factors of 1744 participants from the Maternal-Infant Research on Environment Chemicals (MIREC) Study. Cluster analysis was implemented to categorize participants based on their socio-demographic characteristics, while principal component analysis (PCA) was used to extract the chemicals with similar patterns and to reduce the dimension of the dataset. Next, hypothesis testing determined if the mean converted concentrations of chemical substances differed significantly among women with different socio-demographic backgrounds as well as among clusters. Cluster analysis identified six main socio-demographic clusters. Eleven components, which explained approximately 70% of the variance in the data, were retained in the PCA. Persistent organic pollutants (PCB118, PCB138, PCB153, PCB180, OXYCHLOR and TRANSNONA) and phthalates (MEOHP, MEHHP and MEHP) dominated the first and second components, respectively, and the first two components explained 25.8% of the source variation. Prenatal exposure to persistent organic pollutants (first component) were positively associated with women who have lower education or higher income, were born in Canada, have BMI ≥25, or were expecting their first child in our study population. MEOHP, MEHHP and MEHP, dominating the second component, were detected in at least 98% of 1744 participants in our cohort study; however, no particular group of pregnant women was identified to be highly exposed to phthalates. While widely recognized as important to studying potential health effects, identifying the mixture of chemicals to which various segments of the population are exposed has been problematic. We present an approach using factor analysis through principal component method and cluster analysis as an attempt to determine the pregnancy exposome. Future studies should focus on how to include these matrices in examining the health effects of prenatal exposure to chemical mixtures in pregnant women and their children.
根据化学物质和结果的不同，孕妇在孕期接触环境化学物质可能会对妊娠和儿童发育产生不良影响，尤其是在妊娠早期接触时。因此，与其关注孕妇对个别化学物质的暴露，不如更多地考虑人类每天会接触多种环境化学物质。本分析的目的是确定孕妇接触的化学混合物模式，并描述接触各种混合物的孕妇特征。统计技术应用于 1744 名 Maternal-Infant Research on Environment Chemicals（MIREC）研究参与者的 28 种化学物质和社会人口因素的同时测量。聚类分析用于根据参与者的社会人口特征对其进行分类，而主成分分析（PCA）用于提取具有相似模式的化学物质并减少数据集的维度。然后，假设检验确定不同社会人口背景的女性以及不同聚类之间的化学物质转换浓度均值是否存在显著差异。聚类分析确定了六个主要的社会人口聚类。PCA 保留了 11 个解释数据方差约 70%的成分。持久性有机污染物（PCB118、PCB138、PCB153、PCB180、OXYCHLOR 和 TRANSNONA）和邻苯二甲酸酯（MEOHP、MEHHP 和 MEHP）分别主导第一和第二成分，前两个成分解释了 25.8%的源变异性。本研究中，孕妇接触持久性有机污染物（第一成分）与受教育程度较低或较高、出生于加拿大、BMI≥25 或在我们研究人群中首次怀孕的女性呈正相关。邻苯二甲酸酯主导第二成分，在我们的队列研究中至少 98%的 1744 名参与者中检测到 MEOHP、MEHHP 和 MEHP，但没有确定特定的孕妇群体对邻苯二甲酸酯高度暴露。虽然广泛认为这对于研究潜在的健康影响很重要，但确定不同人群接触的化学混合物一直存在问题。我们提出了一种使用主成分因子分析和聚类分析的方法，试图确定妊娠暴露组。未来的研究应侧重于如何将这些矩阵纳入研究孕妇及其儿童接触化学混合物对健康的影响。
