Measuring Human Exposure to PBDEs

描述（由申请人提供）：多溴联苯醚（PBDEs）通常用作消费品的阻燃剂，如含有聚氨酯泡沫的电子产品和家具。与多氯联苯（PCBs）结构相似，多氯联苯同系物扰乱激素信号，对发育中的动物的神经系统和生殖系统有毒。在过去的几十年里，人体负担有所增加，在美国（US）最高，其水平比亚洲和欧洲人群高出一个数量级以上，在亚洲和欧洲人群中，多溴二苯醚水平与分娩结果下降和隐睾风险增加有关。饮食和室内环境（灰尘、空气）可能是导致个人接触的重要因素，但主要的接触途径尚不清楚。事实上，在2006年的一份关于多溴二苯醚的报告中，美国环境保护署（Environmental Protection Agency）指出，“有必要提高对接触这些化学物质及其相关危害的认识。”我们提出了一种全面的方法来检查人类暴露于多溴二苯醚。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，并将代表迄今为止对人类多溴二苯醚暴露的最完整评估。在50名马萨诸塞州居民的队列中，我们将进行三轮暴露抽样（每六个月一次），并检查三个微环境：家庭、工作场所和汽车。在每一轮采样中，我们将同时评估多溴二苯醚暴露-反应连续体的多个步骤：(a)使用便携式x射线荧光分析仪估计消费品（潜在来源）中的多溴二苯醚含量，(b)测量从家中、工作场所和汽车收集的灰尘（关键微环境）中的多溴二苯醚，(c)测量个人空气和手擦样品中的多溴二苯醚（个人暴露），(d)测量人血清中的多溴二苯醚（总吸收剂量），(e)测量激素水平（潜在的早期影响）。这项强大的研究设计将产生丰富的重复暴露测量数据集，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是如何进入室内环境的，一般人群是如何暴露于多溴二苯醚的，哪些暴露途径对总吸收剂量贡献最大，以及多溴二苯醚暴露在多大程度上与人类激素水平的变化有关。公共卫生相关性：在美国人体内发现的多溴联苯醚（PBDEs）水平几十年来一直在增加，并且比其他国家高一个数量级，在其他国家，一些研究发现与不良健康结果有关。虽然室内环境被假设为这些阻燃剂的主要来源，但人类接触的来源和途径尚不清楚。拟议的项目将更全面地了解多溴二苯醚是如何进入室内环境的，人们是如何接触到多溴二苯醚的，以及它们在多大程度上可能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.