Measuring Human Exposure to PBDEs

描述(由申请人提供)：多溴二苯醚(PBDEs)通常用作含有聚氨酯泡沫塑料的电子产品和家具等消费品中的阻燃剂。在结构上类似于多氯联苯(PCB)，几种PBDE同系物扰乱激素信号，并对发育中的动物的神经和生殖系统有毒。在过去的几十年里，人体的负担有所增加，美国的人体负担最高，那里的水平比亚洲和欧洲人口的水平高出一个数量级以上，在亚洲和欧洲人口中，多溴联苯醚水平与出生结局下降和隐睾症风险增加有关。饮食和室内环境(粉尘、空气)可能是导致个人接触的重要因素，但主要接触途径尚不清楚。事实上，在2006年关于多溴二苯醚的一份报告中，美国环境保护局确定了“需要更好地了解接触这些化学物质及其相关危险”。我们提出了一种全面的方法来检查人类对多溴二苯醚的暴露。拟议的研究旨在解决多溴二苯醚研究基础中存在的一系列重要差距，将是迄今为止对人类多溴二苯醚暴露情况进行的最全面的评估。在一个由50名马萨诸塞州居民组成的队列中，我们将进行三轮暴露采样(每隔六个月)，并检查三个微环境：家庭、工作场所和汽车。在每一轮采样中，我们将同时评估暴露-反应连续体的多个步骤中的多个步骤，方法是(A)使用便携式X射线荧光分析仪估计消费品(潜在来源)的多溴二苯醚含量，(B)测量从家庭、工作场所和汽车(关键微环境)收集的粉尘中的多溴二苯醚，(C)测量个人空气和手擦样本中的多溴二苯醚(个人暴露)，(D)测量人体血清中的多溴二苯醚(总吸收剂量)，以及(E)测量激素水平(潜在的早期影响)。这一强大的研究设计将生成重复暴露测量的丰富数据集，并允许对多溴二苯醚的身体负担和激素水平进行纵向评估。因此，拟议的研究将更全面地了解多溴二苯醚如何进入室内环境，普通人群如何接触多溴二苯醚，哪些暴露途径对总吸收剂量的贡献最大，以及多溴二苯醚暴露可能在多大程度上与人体激素水平的变化有关。与公共健康相关：在美国人体内发现的多溴二苯醚(PBDEs)水平几十年来一直在增加，比其他国家高出一个数量级，在其他国家，一些研究发现与不利的健康后果有关。虽然室内环境被认为是这些阻燃剂的主要来源，但人类接触这些阻燃剂的来源和途径尚不清楚。拟议的项目将使人们更全面地了解多溴二苯醚如何进入室内环境，人们如何接触，以及它们可能在多大程度上与人类激素水平有关。

DESCRIPTION (provided by applicant): Polybrominated diphenyl ethers (PBDEs) are commonly used as fire retardants in consumer products such as electronics and furniture containing polyurethane foam. Structurally similar to polychlorinated biphenyls (PCBs), several PBDE congeners perturb hormonal signaling and are toxic to the nervous and reproductive systems of developing animals. Human body burdens have increased over the last several decades and are highest in the United States (US), where levels are more than an order of magnitude higher than in Asian and European populations in which PBDE levels are associated with decreased birth outcomes and increased risk of cryptorchidism. Diet and the indoor environment (dust, air) are likely important factors that contribute to personal exposure, but the predominant route of exposure is not known. Indeed, in a 2006 report on PBDEs, the US Environmental Protection Agency identified the "need for improved understanding of exposure to these chemicals and the associated hazards." We propose a comprehensive approach to examining human exposure to PBDEs. The proposed study has been designed to address a range of important gaps that exist in the PBDE research base and would represent the most complete assessment of human PBDE exposure to date. In a cohort of fifty Massachusetts residents, we will conduct three rounds of exposure sampling (at six month intervals) and examine three microenvironments: the home, workplace, and car. During each sampling round, we will concurrently assess PBDEs at multiple steps of the exposure-response continuum by (a) estimating the PBDE content of consumer products (potential sources) using a portable x-ray fluorescence analyzer, (b) measuring PBDEs in dust collected from the home, workplace and car (key microenvironments), (c) measuring PBDEs in personal air and hand-wipe samples (personal exposure), (d) measuring PBDEs in human serum (total absorbed dose), and (e) measuring hormone levels (potential early effects). This powerful study design will generate a rich dataset of repeated exposure measures and allow for a longitudinal assessment of PBDE body burden and hormone levels. Accordingly, the proposed research will provide a more complete understanding of how PBDEs enter the indoor environment, how the general population is exposed to PBDEs, which exposure routes contribute most to total absorbed dose, and the extent to which PBDE exposure may be associated with changes in hormone levels in humans. PUBLIC HEALTH RELEVANCE: The levels of polybrominated diphenyl ethers (PBDEs) found in the bodies of Americans have increased for decades and are an order of magnitude higher than in other countries where a few studies have found associations with adverse health outcomes. Although the indoor environment is hypothesized to be the major source of these flame retardants, the sources and routes of human exposure are not well understood. The proposed project will provide a more complete understanding of how PBDEs enter the indoor environment, how people are exposed, and the extent to which they may be associated with human hormones levels.