Chronic Respiratory Effect and Control of Occupational Exposure of Wildland Firefighters to Smoke

工程摘要 与野火易发地区一般人群的零星暴露不同， 消防队员（WFF）对WF烟雾是经常性的，最近变得更加如此，由于增加了 被野火和规定的（管理的）火灾烧毁的土地面积。WFF暴露于升高水平的WF 在野外灭火时吸烟。本文研究了1998年10月至1999年10月间WF烟气中活性粒子的浓度 火线至少比美国基于健康的空气质量标准高出一个数量级。 在火线上的WFF的吸入暴露加剧，因为他们在多天内工作时间延长 每年在火线上。此外，荒地消防大多在没有任何呼吸保护的情况下进行， 因为目前没有呼吸器被批准用于该职业。然而，关于慢性呼吸道疾病的知识 缺乏这种曝光的效果。拟议的研究旨在解决NIOSH的“公共安全”部门， 及其“呼吸系统健康”和“癌症、生殖和心血管疾病”跨部门， 职业性白细胞烟雾暴露与肺功能亚临床指标的关系 呼吸道中的健康损害和癌症相关分子变化。因此，假设 建议的研究是：1）累积反复WF烟雾暴露诱导不良的长期 WFF之间的呼吸影响，以及2）空气净化呼吸器（APR）的情景使用期间， 峰值颗粒暴露浓度的降低将减少暴露和不利的急性生理反应。 第一个假设将通过比较鼻粘膜中DNA甲基化和基因表达的变化来验证。 上皮细胞和肺功能之间的WFF和对照组之间的三年期间的紧急 按年龄、性别和种族匹配的医疗技术人员（EMT）（N = 50/组）。拟议的成果是 疾病前兆，并与表征可能在接触后很长时间内演变的疾病风险有关， 退休第二个假设将通过比较尿生物标志物的交叉移位变化来检验， 暴露、鼻上皮中的基因表达和WFF中的血清促炎性细胞因子（N = 100）。 35)当他们在规定的烧伤处工作时，在佩戴APR和不佩戴APR的情况之间。 拟议研究的目标与NIOSH的优先校外研究目标保持一致，以减少 职业性癌症和呼吸道疾病以及导致这些疾病的暴露。研究完成后， 我们将确定累积职业暴露于WF烟雾的不良呼吸影响， 以及一个切实可行的方法来减轻它们。拟议研究的预期产出， 包括可公开获得结果和出版物，将直接告知NIOSH的优先目标， 野外消防员的暴露和疾病发生率。这些产出，也将 通过虚拟研讨会向利益相关者开放，将有助于对WF烟雾进行适当的风险评估 风险暴露、风险暴露和风险缓解策略的制定以及测试其有效性的方法。

Project Abstract Unlike the sporadic exposure of the general population in wildfire prone areas, exposure of wildland firefighters (WFFs) to WF smoke is recurrent, and has recently become more so due to the increase in the acreage of land burned by wildfires and prescribed (managed) fires. WFFs are exposed to elevated levels of WF smoke while working at wildland fires. The airborne concentrations of the reactive particles in WF smoke at the fireline are at least an order of magnitude higher than the health-based air quality standards in the U.S. The inhalation exposure of WFFs at the fireline is exacerbated because they work extended hours on multiple days per year at the fireline. Additionally, wildland firefighting is conducted mostly without any respiratory protection, as no respirator is currently approved for the profession. Nevertheless, knowledge about the chronic respiratory effects of such exposure is lacking. The proposed study is designed to address NIOSH’s “Public Safety” sector, and its “Respiratory Health” and “Cancer, Reproductive, and Cardiovascular Diseases” cross-sectors by assessing the association between occupational WF smoke exposure and subclinical indicator of pulmonary health impairment and cancer-related molecular changes in the respiratory airways. Therefore, the hypotheses of the proposed study are: 1) that cumulative recurrent WF smoke exposure induces adverse long-term respiratory effects among WFFs, and 2) that a situational use of an air purifying respirator (APR) during periods of peak particulate exposure concentrations will reduce exposure and adverse acute physiological responses. The first hypothesis will be tested by comparing changes in DNA methylation and gene expression in the nasal epithelium and lung function across a three-year period between WFFs and a control group of emergency medical technicians (EMTs) matched by age, sex and ethnicity (N = 50/group). The proposed outcomes are disease precursors and are relevant for characterizing risk of disease that may evolve long after exposure or retirement. The second hypothesis will be tested by comparisons of cross-shift changes in urinary biomarkers of exposure, gene expression in the nasal epithelium, and serum pro-inflammatory cytokines among WFFs (N = 35) between occasions when they wear the APR and when they do not, while working at prescribed burns. The objective of the proposed study is well aligned with NIOSH’s priority extramural research goals to reduce occupational cancer and respiratory disease and exposures causing them. Following the completion of the study, we would have determined the adverse respiratory effects of cumulative occupational exposure to WF smoke and a practical approach to mitigate them. The envisaged outputs from the proposed research, which would include publicly accessible results and publications, would directly inform NIOSH’s priority goal to reduce incidence of exposure and illnesses among wildland firefighters. These outputs, which will also be made accessible to stakeholders via a virtual workshop, will contribute to appropriate risk assessment of WF smoke exposure, the development of exposure and risk mitigation strategies, and methods to test their effectiveness.