Libby Epidemiology Research Program

描述（由申请人提供）：自20世纪20年代以来，MT . Libby的居民一直暴露于石棉矿物（Libby角闪石，或LA），包括透闪石和其他受管制的角闪石类型，以及不受管制的纤维，包括winchite和richterite (Meeker et al. 2003)，通过蛭石矿山和加工厂的运营，直到1990年矿山关闭。1990年以前的暴露是职业性、半职业性（通过与接触la的工人居住）和/或环境性；Peipins（2003）详细描述了主要的暴露途径。自该矿关闭以来，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的物质的干扰，环境保护局在2000年开始的现场清理工作减轻了污染。ATSDR（2003年）总结了Libby社区暴露于LA的健康后果，包括石棉沉滞症和胸膜瘢痕的发病率增加，石棉沉滞症、肺癌和间皮瘤的死亡率增加，自身免疫抗体异常和诊断出的全身自身免疫疾病的患病率增加。计划进行的研究旨在解决几个与接触硫氰酸盐对健康的影响有关的问题：1)儿童时期接触硫氰酸盐可能存在的特殊风险，包括低累积接触水平的影响；2): la相关性肺部疾病异常快速和损害的特征；3)非肺部健康影响，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少年时期接触硫代酚的后果，并将允许评估低累积水平接触对人体健康的影响，这是一个对制定基线风险评估和确定可被认为对利比社区（包括儿童）安全的环境残留污染水平相当重要的问题。有相当多的临床证据表明，与大量暴露于商用形式石棉的工人相比，与暴露于LA相关的肺部疾病具有更严重的病程，其瘢痕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暴露于LA后胸部CT扫描上可见的石棉相关肺实质和/或胸膜瘢痕进展是否比长期高累积暴露水平的石棉绝缘体更快。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疾病的患病率，将在自身免疫结果研究中评估LA暴露的非肺部后果，即自身免疫异常和疾病。

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.