权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Evaluating impacts of occupational exposure limits for silica using g-estimation

使用 g 估计评估二氧化硅职业接触限值的影响

基本信息

批准号：
9145230
负责人：
Sally Picciotto
金额：
$ 7.85万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-01 至 2018-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9145230
关键词：
Evaluating impacts occupational exposure limits

项目摘要

DESCRIPTION (provided by applicant): When workers with poor health decrease their exposure but healthy workers do not, it becomes difficult to detect an association even when exposure causes disease. This healthy worker survivor bias is particularly problematic in studies of relationships between long-term occupational exposures and chronic diseases. Satisfactory solutions to the healthy worker survivor effect using conventional regression analysis do not exist. Fortunately, alternative methods have been developed that do eliminate this type of bias; only recently have these "g-methods" been applied in an occupational setting. Our group successfully applied them to a large mortality study and found clear evidence for relationships that had eluded researchers using more conventional methods. Recent work extends the use of these methods to a continuous exposure, and we have developed a public health approach that evaluates explicitly the impacts of enforcing new exposure limits. Workers in the diatomaceous earth industry are exposed to crystalline silica, which causes silicosis and other non-malignant respiratory diseases and is now classified as a carcinogen. Previous analyses of cohorts of diatomaceous earth workers have not adjusted for healthy worker survivor bias. Relatively weak lung cancer results and protective estimates for cardiovascular outcomes may be further biased due to censoring by competing risks. We therefore aim to apply g-methods to address these two sources of bias in hopes that doing so will enable us to uncover clearer evidence of causal relationships between crystalline silica and mortality from lung cancer, COPD, and heart disease. A general industry permissible exposure limit (PEL) of 100µg/m3 has been in effect for silica since 1971 and has never been updated; however, hearings were held in March 2014 regarding a proposed federal standard that introduces a new PEL of 50µg/m3. We will evaluate the potential impact of the proposed exposure limit for respirable crystalline silica by estimating years of life saved, evaluating effects of interventions rather than comparing groups of workers with different exposure histories. This project addresses the Mining Sector and the Cancer, Reproductive and Cardiovascular Disease NORA cross-sector program. Its rigorous analytical methods will provide clearer epidemiologic evidence for the effects of inhaled silica, framing results in terms of impacts of occupational exposure limits using a metric that is easy to communicate to policymakers and the general public. This is directly relevant to NIOSH's r2p initiative. Outcomes and Outputs will include scientific research papers in peer-reviewed journals and presentations at conferences. By reducing bias in etiologic studies of workplace exposure and evaluating the potential impacts of occupational exposure limits, the project will lead to better control of occupational health hazards.

描述（由申请人提供）：当健康状况不佳的工人减少接触，而健康工人没有减少接触时，即使接触导致疾病，也很难检测出相关性。这种健康工人幸存者的偏见在长期职业暴露与慢性病之间关系的研究中尤其成问题。使用传统的回归分析，健康工人的幸存者效应的满意的解决方案不存在。幸运的是，替代方法已经开发出来，消除了这种类型的偏见;直到最近，这些“g方法”才被应用于职业环境。我们的研究小组成功地将它们应用于一项大型死亡率研究，并找到了研究人员使用更传统方法无法找到的明确证据。最近的工作将这些方法的使用扩展到连续暴露，我们已经开发出一种公共卫生方法，明确评估执行新的暴露限制的影响。硅藻土行业的工人暴露于结晶二氧化硅，导致硅肺病和其他非恶性呼吸道疾病，现在被列为致癌物质。以前对硅藻土工人队列的分析没有调整健康工人幸存者的偏倚。由于竞争风险删失，相对较弱的肺癌结果和心血管结局的保护性估计可能会进一步偏倚。因此，我们的目标是应用g方法来解决这两个偏差来源，希望这样做能够使我们能够发现更清晰的证据，证明结晶二氧化硅与肺癌，COPD和心脏病死亡率之间的因果关系。自1971年以来，二氧化硅的一般行业允许暴露限值（PEL）为100µg/m3，从未更新;然而，2014年3月举行了关于拟议的联邦标准的听证会，该标准引入了50µg/m3的新PEL。我们将通过估算以下因素来评估拟议的可吸入结晶二氧化硅接触限值的潜在影响：年的生命挽救，评估干预措施的效果，而不是比较工人群体与不同的接触历史。该项目涉及采矿部门和癌症、生殖和心血管疾病诺拉跨部门方案。其严格的分析方法将为吸入二氧化硅的影响提供更清晰的流行病学证据，使用易于与政策制定者和公众沟通的度量标准，根据职业暴露限值的影响制定结果。这与NIOSH的R2 P倡议直接相关。成果和产出将包括同行评审期刊上的科学研究论文和会议上的演讲。通过减少工作场所接触的病因学研究中的偏差和评估职业接触限值的潜在影响，该项目将导致更好地控制职业健康危害。