Endocrine disrupting and immune effects of Triclosan in children

描述(申请人提供)：接触三氯生，一种用于肥皂、牙膏和其他个人护理产品的抗菌剂，非常普遍，75%的美国人体内可检测到三氯生的含量。体外和动物研究表明，三氯生是一种内分泌干扰物。在啮齿动物的研究中，在发育的关键窗口暴露于三氯生会降低甲状腺激素甲状腺激素(T4)的水平，增加过敏反应和哮喘样反应，降低男性的睾丸素，并改变女性的青春期时间。到目前为止，只有一小部分研究考察了三氯生对人类健康的影响，重点是学龄儿童和成年人。这些研究在一定程度上证实了对内分泌和免疫系统的影响，但它们没有解决子宫内暴露的问题--子宫是内分泌干扰和免疫发育的关键时期--因此可能低估了三氯生对健康的潜在影响。美国食品和药物管理局(FDA)和环境保护局(EPA)都在着手对三氯生进行全面的监管审查，但面临着缺乏人类数据的挑战。迫切需要高质量的独立研究，评估产前和儿童早期接触三氯生与随后的健康影响之间的关系。萨利纳斯母亲和儿童健康评估中心(CHAMACOS)是一项纵向出生队列研究，收集了300多名儿童从出生前到12岁期间环境暴露、健康和发育的全面数据。我们建议表征CHAMACOS母亲及其5岁和9岁孩子的尿三氯生浓度，并研究这种暴露对以下方面的潜在影响：1)孕妇和新生儿的甲状腺激素动态平衡；2)5岁和7岁儿童的过敏和哮喘症状；3)9至12岁儿童的青春期时间和性激素水平。我们已经收集了实现这些目标所需的大部分数据，初步的粗略分析表明，在这个队列中，三氯生与T4降低和哮喘症状风险增加有关。然而，完成尿三氯生测量、获得更多结果数据和进行复杂的数据分析所需的工作，如果没有专门的资金，就无法完成纵向影响和混杂的控制。这项研究是探索性的，因为它是第一个关于发育性三氯生暴露的纵向研究；发育性，因为它为未来的深入研究奠定了基础；以及高风险，因为我们希望及时得到结果，为即将做出的政策决定提供信息。依靠丰富的现有数据，该项目可以在短短两年内完成，有望产生高度的监管和科学影响。

DESCRIPTION (provided by applicant): Exposure to triclosan, an antibacterial agent used in soaps, toothpaste, and other personal care products, is widespread, with 75% of Americans having detectable levels in their bodies. In vitro and animal studies show that triclosan is an endocrine disruptor. In rodent studies, triclosan exposure during critical windows of development lowers levels of the thyroid hormone thyroxine (T4), increases allergic sensitivity and asthma-like response, decreases testosterone in males, and alters pubertal timing in females. To date, only a small number of studies have examined health effects of triclosan in humans, focusing on school-age children and adults. These studies provide some confirmation of effects on endocrine and immune systems, but they do not address exposure in utero - a critical period for endocrine disruption and immune development - and thus likely underestimate triclosan's potential health impact. Both the U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) are embarking on comprehensive regulatory reviews of triclosan, but are challenged by a dearth of human data. High-quality, independent research assessing associations of prenatal and early childhood triclosan exposures with subsequent health effects are urgently needed. The Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) is a longitudinal birth cohort study that has gathered comprehensive data on environmental exposures, health, and development in more than 300 children who have participated from before birth through age 12. We propose to characterize urinary triclosan concentrations from CHAMACOS mothers during pregnancy and their children at 5 and 9 years of age and to examine the potential impact of this exposure on: 1) thyroid hormone homeostasis in pregnant women and newborns, 2) allergy and asthma symptoms in children at ages 5 and 7, and 3) timing of puberty and sex hormone levels in children between ages 9 and 12. We have already collected most of the data needed to achieve these aims, and crude, preliminary analyses suggest associations of triclosan with decreased T4 and increased risk of asthma symptoms in this cohort. However, the work needed to finalize urinary triclosan measurements, obtain additional outcome data, and conduct sophisticated data analyses that control for longitudinal effects and confounding cannot be completed without dedicated funding. This study is exploratory, because it is the first longitudinal study of developmental triclosan exposure; developmental, in that it lays groundwork for future in-depth research; and high risk, because we hope to have results in time to inform pending policy decisions. By relying on a rich existing data, this project can be completed in just two years, promising high regulatory and scientific impact.