Duncan Sara, Reed Charlie, Spurlock Taylin, Sugg Margaret M, Runkle Jennifer D
School of Health Sciences Western Carolina University NC Cullowhee USA.
North Carolina Institute for Climate Studies North Carolina State University NC Asheville USA.
Geohealth. 2023 Oct 20;7(10):e2023GH000860. doi: 10.1029/2023GH000860. eCollection 2023 Oct.
In 2016, unprecedented intense wildfires burned over 150,000 acres in the southern Appalachian Mountains in the United States. Smoke from these fires greatly impacted the region and exposure to this smoke was significant. A bidirectional case-crossover design was applied to assess the relationship between PM (a surrogate for wildfire smoke) exposure and respiratory- and cardiovascular-related emergency department (ED) visits in Western North Carolina during these events. For 0-, 3-, and 7-day lags, findings indicated a significant increase in the odds of being admitted to the ED for a respiratory (ORs: 1.055, 95% CI: 1.048-1.063; 1.083, 1.074-1.092; 1.066, 1.058-1.074; respectively) or cardiovascular event (ORs: 1.052, 95% CI: 1.045-1.060; 1.074, 1.066-1.081; 1.067, 1.060-1.075; respectively) for every 5 μg/m increase in PM over a chosen cutpoint of 20.4 μg/m. For all endpoints assessed except for emphysema, there were statistically significant increases in odds from 5.1% to 8.3%. In general, this increase was most pronounced 3 days after exposure. Additionally, individuals aged 55+ generally experience higher odds of heart disease at the 3- and 7-day lag points, and Black/African Americans generally experience higher odds of asthma at the 3-day lag point. In general, larger fires and increased numbers of fires within counties resulted in higher health burden at same day exposure. In a secondary analysis, the odds of an ED visit increased by over 40% in several cases among people exposed to days above the Environmental Protection Agency 24-hr PM standard of 35 μg/m. Our findings provide new understanding on the health impacts of wildfires on rural populations in the southeastern US.
2016年，美国阿巴拉契亚山脉南部发生了史无前例的严重野火，过火面积超过15万英亩。这些火灾产生的烟雾对该地区造成了极大影响，人们大量暴露于这种烟雾之中。研究采用双向病例交叉设计，评估了北卡罗来纳州西部在这些事件期间，细颗粒物（PM，野火烟雾的替代指标）暴露与呼吸及心血管相关急诊就诊之间的关系。对于滞后0天、3天和7天的情况，研究结果表明，当PM浓度超过选定的20.4μg/m切点每增加5μg/m时，因呼吸系统疾病（比值比分别为：1.055，95%置信区间：1.048 - 1.063；1.083，1.074 - 1.092；1.066，1.058 - 1.074）或心血管疾病事件（比值比分别为：1.052，95%置信区间：1.045 - 1.060；1.074，1.066 - 1.081；1.067，1.060 - 1.075）而入住急诊科的几率显著增加。对于除肺气肿外评估的所有终点，几率从5.1%到8.3%有统计学显著增加。总体而言，这种增加在暴露后3天最为明显。此外，55岁及以上的个体在滞后3天和7天时间点患心脏病的几率通常更高，黑人/非裔美国人在滞后3天时间点患哮喘的几率通常更高。总体而言，县内更大规模的火灾以及火灾数量增加，导致当日暴露时的健康负担加重。在一项二次分析中，在暴露于超过美国环境保护局24小时PM标准35μg/m天数的人群中，有几种情况下急诊就诊几率增加了40%以上。我们的研究结果为野火对美国东南部农村人口的健康影响提供了新的认识。
