Wildfire activity in the western United States (US) has been increasing, a trend that has been correlated with changing patterns of temperature and precipitation associated with climate change. Health effects associated with exposure to wildfire smoke and fine particulate matter (PM_2.5) include short- and long-term premature mortality, hospital admissions, emergency department visits, and other respiratory and cardiovascular incidents. We estimate PM_2.5 exposure and health impacts for the entire continental US from current and future western US wildfire activity projected for a range of future climate scenarios through the 21st century. We use a simulation approach to estimate wildfire activity, area burned, fine particulate emissions, air quality concentrations, health effects, and economic valuation of health effects, using established and novel methodologies. We find that climatic factors increase wildfire pollutant emissions by an average of 0.40% per year over the 2006–2100 period under Representative Concentration Pathway (RCP) 4.5 (lower emissions scenarios) and 0.71% per year for RCP8.5. As a consequence, spatially weighted wildfire PM_2.5 concentrations more than double for some climate model projections by the end of the 21st century. PM_2.5 exposure changes, combined with population projections, result in a wildfire PM2.5-related premature mortality excess burden in the 2090 RCP8.5 scenario that is roughly 3.5 times larger than in the baseline period. The combined effect of increased wildfire activity, population growth, and increase in the valuation of avoided risk of premature mortality over time results in a large increase in total economic impact of wildfire-related PM_2.5 mortality and morbidity in the continental US, from roughly $7 billion per year in the baseline period to roughly $36 billion per year in 2090 for RCP4.5, and $43 billion per year in RCP8.5. The climate effect alone accounts for a roughly 60% increase in wildfire PM2.5-related premature mortality in the RCP8.5 scenario, relative to baseline conditions.

美国西部的野火活动一直在增加，这一趋势与与气候变化有关的温度和降水模式的变化有关。暴露于野火烟雾和细颗粒物（PM _2.5）相关的健康影响包括短期和长期过早死亡，住院，急诊就诊以及其他呼吸道和心血管事件。我们估计PM _2.5当前和未来的美国西部野火活动对整个美国大陆的辐射和健康影响，预计将在整个21世纪出现在未来的各种气候情景中。我们使用一种模拟方法来评估野火活动，燃烧面积，细颗粒物排放，空气质量浓度，健康影响以及对健康影响的经济评估，方法是采用既有的和新颖的方法。我们发现，在代表性浓度途径（RCP）4.5（排放降低的情景）下，气候因素在2006-2100年期间每年平均增加野火污染物排放0.40％，对于RCP8.5则每年增加0.71％。结果，到21世纪末，对于某些气候模型预测，空间加权野火PM _2.5的浓度增加了一倍以上。下午_2.5暴露的变化，再加上人口预测，导致2090 RCP8.5情景中与野火PM2.5相关的过早死亡的超重负担大约是基线期的3.5倍。野火活动增加，人口增长以及避免的过早死亡风险的评估价值随时间增加的综合影响，导致与野火相关的PM _2.5死亡率和发病率在美国大陆的总体经济影响从大约7美元大幅增加。在基准期间，每年的投资额为50亿美元，到2090年，RCP4.5约为每年360亿美元，RCP8.5每年约为430亿美元。相对于基准条件，在RCP8.5情景中，仅气候影响就导致了与野火PM2.5相关的过早死亡的大约60％的增加。