Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, USA.
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, USA.
Int J Hyg Environ Health. 2021 Aug;237:113827. doi: 10.1016/j.ijheh.2021.113827. Epub 2021 Aug 14.
Wildland firefighters at prescribed burns are exposed to elevated levels of wildland fire smoke (WFS) while performing physically demanding tasks. WFS exposure has been linked to increases in hospital and emergency admissions for cardiovascular disorders in the general population. However, knowledge about the cardiovascular effect of occupational WFS exposure among wildland firefighters is limited. To provide a better understanding of the effect of this exposure scenario on acute hemodynamic responses, resting systolic/diastolic blood pressure (SBP/DBP) and heart rate (HR) of wildland firefighters were measured before (pre-shift), after (post-shift), and the morning (next morning) immediately following prescribed burn shifts (burn days) and regular work shifts (non-burn days). A total of 38 firefighters (34 males and 4 females) participated in this study and resting BP and HR were recorded on 9 burn days and 7 non-burn days. On burn days, HR significantly increased from pre-to post-shift (13.25 bpm, 95% CI: 7.47 to 19.02 bpm) while SBP significantly decreased in the morning following the prescribed burns compared to pre-shift (-6.25 mmHg, 95% CI: -12.30 to -0.20 mmHg). However, this was due to the decrease of SBP in the firefighters who were hypertensive (-8.46 mmHg, 95% CI: -16.08 to -0.84 mmHg). Significant cross-shift reductions (post-shift/next morning vs. pre-shift) were observed in SBP on burn days compared to non-burn days (-7.01 mmHg, 95% CI: -10.94 to -3.09 mmHg and -8.64 mmHg, 95% CI: -13.81 to -3.47 mmHg, respectively). A significant reduction on burn days was also observed from pre-shift to the following morning for HR compared to non-burn days (-7.28 bpm, 95% CI: -13.50 to -1.06 bpm) while HR significantly increased in pre-to post-shift on burn days compared to non-burn days (10.61 bpm, 95% CI: 5.05 to 16.17 bpm). The decreased BP observed in wildland firefighters might be due to a high level of carbon monoxide exposure and exercise-induced hypotension. The increase in HR immediately after prescribed burns might be attributable to WFS exposure and physical exertion in prescribed burn shifts. The results suggest that wildland firefighting exposure might cause a distinct hemodynamic response, including SBP reduction and HR increment, especially for those who have pre-existing hypertension.
在进行规定的燃烧作业时，野外消防员会暴露在高水平的野火烟雾（WFS）中，同时还要进行体力要求高的任务。WFS 暴露已被证明会增加一般人群因心血管疾病住院和急诊入院的风险。然而，关于野外消防员职业性 WFS 暴露对心血管的影响的知识是有限的。为了更好地了解这种暴露情况对急性血液动力学反应的影响，在规定的燃烧作业（燃烧日）和常规工作班次（非燃烧日）之前（班前）、之后（班后）和之后的早上（次日早晨）测量了野外消防员的静息收缩压/舒张压（SBP/DBP）和心率（HR）。共有 38 名消防员（34 名男性和 4 名女性）参与了这项研究，在 9 个燃烧日和 7 个非燃烧日记录了静息血压和心率。在燃烧日，心率从班前到班后显著增加（13.25 bpm，95%CI：7.47 至 19.02 bpm），而与班前相比，规定燃烧后清晨的 SBP 显著下降（-6.25mmHg，95%CI：-12.30 至 -0.20mmHg）。然而，这是由于高血压消防员的 SBP 下降（-8.46mmHg，95%CI：-16.08 至 -0.84mmHg）所致。与非燃烧日相比，在燃烧日，SBP 从班前到班后（-7.01mmHg，95%CI：-10.94 至 -3.09mmHg 和 -8.64mmHg，95%CI：-13.81 至 -3.47mmHg）和次日清晨（-7.01mmHg，95%CI：-10.94 至 -3.09mmHg 和 -8.64mmHg，95%CI：-13.81 至 -3.47mmHg）均观察到显著的班次间降低。与非燃烧日相比，在燃烧日，HR 从班前到次日清晨也显著下降（-7.28 bpm，95%CI：-13.50 至 -1.06 bpm），而与非燃烧日相比，HR 在班前到班后显著增加（10.61 bpm，95%CI：5.05 至 16.17 bpm）。野外消防员观察到的血压下降可能是由于高水平的一氧化碳暴露和运动引起的低血压。规定燃烧后即刻心率的增加可能归因于 WFS 暴露和规定燃烧作业中的体力消耗。结果表明，野外消防作业可能会引起明显的血液动力学反应，包括 SBP 降低和 HR 增加，特别是对于那些患有高血压的人。
