Wildland firefighters are repeatedly exposed to elevated levels of wildland fire smoke (WFS) while protecting lives and properties from wildland fires. Studies reporting personal exposure concentrations of air pollutants in WFS during fire suppression or prescribed burn activities have been geographically limited to the western and southeastern United States. The objective of this study is to characterize exposure concentrations of air pollutants in WFS emissions among wildland firefighters who conducted prescribed burns in the Midwest. Between 2016 and 2019, a total of 35 firefighters (31 males and 4 females, age of 35.63 ± 9.31 years) were recruited to participate in this study. Personal particulate matter 2.5 (PM_2.5) and carbon monoxide (CO) exposure concentrations were measured during prescribed burns. The level of black carbon (BC) in WFS particulates was determined using the light transmission technique, while trace metal composition was analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The results showed geometric means for PM_2.5, CO, and BC concentrations were 1.43 ± 0.13 mg/m³, 7.02 ± 0.69 ppm, and 58.79 ± 5.46 μg/m³, respectively. Although no occupational exposure limits (OELs) were exceeded by 8-h time-weighted average (TWA) exposure concentration observed in the firefighters, a total of 28 personal CO exposure concentrations were above the National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL) Ceiling (200 ppm) for CO. PM_2.5 and CO concentrations were about 2–7 times higher in the Midwest than the other regions. Firefighters who performed holding had higher CO exposure concentrations compared to firefighters who performed lighting (p < 0.01), while lighters were exposed to higher level of BC in the smoke particulates (p < 0.01), possibly due to the domination of exposure by different combustion sources and stages. The levels of trace metals in WFS particulates were well below the corresponding OELs and no task-related difference was observed except for manganese. Our results suggest that wildland firefighters in the midwestern region have higher WFS exposures while working at prescribed burns compared to those western and southeastern United States.

野外消防员反复暴露在高水平的野火中，同时保护生命和财产免受野火的伤害。研究报告指出，在灭火或规定的燃烧活动期间，世界粮食首脑会议中空气污染物的个人暴露浓度在地理上仅限于美国西部和东南部。这项研究的目的是确定在中西部进行规定燃烧的野外消防员在WFS排放中空气污染物的暴露浓度。在2016年至2019年之间，共招募了35名消防员（男31例，女4例，年龄35.63±9.31岁）参加本研究。个人颗粒物2.5（PM _2.5）和一氧化碳（CO）暴露浓度在规定的烧伤过程中进行了测量。使用光透射技术确定WFS颗粒中的黑碳（BC）含量，同时使用电感耦合等离子体质谱仪（ICP-MS）分析痕量金属成分。结果表明几何用于PM _2.5，CO，和BC浓度分别为1.43±0.13毫克/米³，7.02±0.69 ppm，且58.79±5.46微克/米³， 分别。尽管在消防员中观察到的8小时时间加权平均（TWA）暴露浓度未超过职业接触限值（OELs），但共有28个人的CO暴露浓度高于美国国家职业安全与健康研究所（NIOSH）推荐一氧化碳的暴露极限（REL）上限（200 ppm）。中西部地区的PM _2.5和一氧化碳浓度比其他地区高约2–7倍。与进行照明的消防员相比，持火的消防员的CO暴露浓度更高（p  <0.01），而打火机的烟雾颗粒中的BC浓度更高（p <0.01），可能是由于不同燃烧源和燃烧阶段对暴露的控制。WFS颗粒中的痕量金属含量远低于相应的OEL，除锰外，未观察到与任务相关的差异。我们的结果表明，与美国西部和东南部的消防员相比，中西部地区的野外消防员在进行规定的燃烧时具有更高的WFS暴露量。