Libby Epidemiology Research Program

描述(由申请人提供)：蒙大拿州利比的居民曾接触过石棉状矿物(Libby闪石，或LA)，包括透闪石和其他受监管的角闪石类型，以及未受监管的纤维，包括温闪石和黄铁矿(Meeker等人)。自1920年代以来，通过经营一座蛭石矿和加工厂，直到1990年关闭该矿。1990年之前的接触是职业性、准职业性(通过与接触洛杉矶的工人居住)和/或环境接触；主要接触途径已由Peipins(2003)详细说明。自矿山关闭以来，利比地区的人们继续暴露在残留的石棉污染中，主要是由于含有LA的材料的干扰，而环境保护局于2000年开始的现场清理工作缓解了这种污染。ATSDR(2003)总结了在Libby社区暴露于LA的健康后果，包括石棉肺和胸膜疤痕形成的比率增加，石棉肺、肺癌和间皮瘤的死亡率增加，以及自身免疫抗体异常和诊断的系统性自身免疫性疾病的发病率增加。计划中的研究试图解决与暴露于LA的健康后果有关的几个问题：1)在儿童时期暴露的可能的特殊风险，包括低累积暴露水平的影响；2)与LA相关的肺部疾病的异常迅速和损害的特征；以及3)非肺健康的影响，特别是自身免疫性疾病。高中毕业生研究将调查仅发生在儿童和青春期的LA暴露的后果，并将允许评估低累积水平暴露对人类健康的影响，这对制定基线风险评估和确定可被认为对Libby社区包括儿童安全的环境残留污染水平具有相当重要的意义。有相当多的临床证据表明，与接触LA相关的肺部疾病的病程更具侵袭性，与大量接触商业使用形式的石棉的工人相比，伤疤形成和肺功能丧失的进展更快。CT进展研究将评估仅在环境中暴露于LA后，胸部CT扫描显示的与石棉相关的肺实质和/或胸膜疤痕的进展是否比长期接触高累积暴露水平的石棉绝缘子的进展更快。暴露于LA的非肺源性后果，即自身免疫异常和疾病，将在自身免疫结果研究中通过评估与暴露措施相关的自身免疫抗体异常和医生诊断的自身免疫性疾病的流行率来进行评估。

Description (Provided by Applicant): Residents of Libby, MT, have been exposed to asbestiform minerals (Libby amphibole, or LA) including tremolite and other regulated amphibole types as well as unregulated fibers including winchite and richterite (Meeker et al. 2003) since the 1920s through the operation of a vermiculite mine and processing plant until 1990, when the mine was closed. Exposure prior to 1990 had been occupational, para-occupational (via residence with an LA-exposed worker) and/or environmental; the main exposure pathways have been detailed by Peipins (2003). Since closure of the mine, people in the Libby area have continued to be exposed to residual asbestos contamination principally via disturbance of LA-containing materials in place, mitigated by site cleanup efforts begun by the EPA in 2000. The health consequences of exposure to LA in the Libby community have been summarized by the ATSDR (2003) and include increased rates of asbestosis and pleural scarring, increased mortality from asbestosis, lung cancer and mesothelioma, and an increase in the prevalence of autoimmune antibody abnormalities and diagnosed systemic autoimmune diseases. The planned studies seek to address several questions regarding the health consequences of exposure to LA: 1) the possible particular risk of exposure during childhood, including effects at low cumulative exposure levels; 2): the unusually rapid and impairing character of LA-related pulmonary disease; and 3) non-pulmonary health effects, specifically autoimmune disorders. The High School Graduates Study will investigate the consequences of exposure to LA that occurs only during childhood and adolescence and will permit an evaluation of the human health effects of exposure at low cumulative levels, an issue of considerable importance to the development of a Baseline Risk Assessment and determinations of levels of residual contamination of the environment that can be considered safe for the Libby community, including children. There is considerable clinical evidence that pulmonary disease associated with exposure to LA has a more aggressive course with more rapid progression of scarring and loss of lung function than is seen among workers heavily exposed to commercially used forms of asbestos. The CT Progression Study will evaluate whether asbestos-related scarring of the lung parenchyma and/or pleura evident on chest CT scans following only environmental exposure to LA progresses more rapidly than is seen in long-term asbestos insulators with high cumulative exposure levels. Non-pulmonary consequences of LA exposure, i.e. autoimmune abnormalities and diseases, will be evaluated in the Autoimmune Outcomes Study by assessing the prevalence of autoimmune antibody abnormalities and physician-diagnosed autoimmune diseases in relation to exposure measures.