Watson Rebecca E, Jacobson Catherine F, Williams Amy Lavin, Howard W Brian, DeSesso John M
Mitretek Systems, 3150 Fairview Park Drive, Falls Church, VA 22033, USA.
Reprod Toxicol. 2006 Feb;21(2):117-47. doi: 10.1016/j.reprotox.2005.07.013. Epub 2005 Sep 21.
The organic solvent trichloroethylene (TCE) is a metal degreasing agent and an intermediate in the production of fluorochemicals and polyvinyl chloride. TCE is also a common, persistent drinking water contaminant. Several epidemiological studies have alleged links between TCE exposure during pregnancy and offspring health problems including congenital heart defects (CHDs); however, the results of these studies are inconsistent, difficult to interpret, and involve several confounding factors. Similarly, the results of animal studies examining the potential of TCE to elicit cardiac anomalies have been inconsistent, and they have often been performed at doses far exceeding the highest levels ever reported in the drinking water. To determine what is known about the relationship between TCE and the incidence of CHDs, a comprehensive analysis of all available epidemiological data and animal studies was performed. Additionally, in vivo and in vitro studies examining possible mechanisms of action for TCE were evaluated. The specific types of heart defects alleged to have been caused by TCE in animal and human epidemiology studies were categorized by the morphogenetic process responsible for the defect in order to determine whether TCE might disrupt any specific developmental process. This analysis revealed that no single process was clearly affected by TCE, providing support that gestational TCE exposure does not increase the prevalence of CHDs. As a final evaluation, application of Hill's causality guidelines to the collective body of data revealed no indication of a causal link between gestational TCE exposure at environmentally relevant concentrations and CHDs.
有机溶剂三氯乙烯（TCE）是一种金属脱脂剂，也是生产含氟化合物和聚氯乙烯的中间体。TCE还是一种常见的、持久性的饮用水污染物。多项流行病学研究称，孕期接触TCE与后代健康问题之间存在关联，包括先天性心脏病（CHD）；然而，这些研究结果并不一致，难以解读，且涉及多个混杂因素。同样，关于TCE引发心脏异常可能性的动物研究结果也不一致，而且这些研究往往是在远远超过饮用水中报告的最高水平的剂量下进行的。为了确定关于TCE与CHD发病率之间关系的已知情况，对所有可用的流行病学数据和动物研究进行了全面分析。此外，还评估了研究TCE可能作用机制的体内和体外研究。在动物和人类流行病学研究中，据称由TCE导致的特定类型心脏缺陷，根据导致该缺陷的形态发生过程进行了分类，以确定TCE是否可能扰乱任何特定的发育过程。该分析表明，没有单一过程明显受到TCE影响，这支持了孕期接触TCE不会增加CHD患病率的观点。作为最终评估，将希尔因果关系准则应用于所有数据后发现，没有迹象表明在环境相关浓度下孕期接触TCE与CHD之间存在因果联系。
