美国斯坦福大学 Burke, Marshall 和哈佛大学 Childs, Marissa L. 的团队在研究野火对美国 PM_2.5 趋势的贡献中取得新进展。相关论文于2023年9月20日发表于国际顶尖学术期刊《自然》杂志上。

研究人员使用 2000 年至 2022 年期间，基于地面和卫星的空气污染数据，来量化野火烟雾对这些 PM_2.5 趋势的贡献。研究发现，至少自 2016 年以来，野火烟雾就已经影响了美国邻近地区近四分之三的州的年平均 PM_2.5 浓度趋势，侵蚀了这些州，在此前几十年平均降低 PM_2.5 浓度方面取得约 25 ％的进展，甚至在许多西部州超过 50 ％的进展，相当于 4 年的空气质量进步。

到 2011 年，烟雾对极端 PM_2.5 浓度天数趋势的影响就可以被探测到了，但这种影响主要出现在西部和中西部的州。在没有进一步干预的情况下，野火导致的环境 PM_2.5 浓度增加，不受当前《空气污染法》的管制，研究表明，随着气候持续变暖，野火对地区和国家空气质量趋势的影响可能会增加。

据介绍，在过去的几十年里，美国环境空气质量有了稳步的改善，一部分是受益于公共政策的结果，同时也给公众的健康带来了一定的好处。然而，在美国大部分地区，直径小于 2.5 μm的颗粒物(PM_2.5)的环境浓度(受《清洁空气法案》管制的污染物)的近期趋势已经停滞或开始逆转。

附：英文原文

Title: The contribution of wildfire to PM_2.5 trends in the USA

Author: Burke, Marshall, Childs, Marissa L., de la Cuesta, Brandon, Qiu, Minghao, Li, Jessica, Gould, Carlos F., Heft-Neal, Sam, Wara, Michael

Issue&Volume: 2023-09-20

Abstract: Steady improvements in ambient air quality in the USA over the past several decades, in part a result of public policy, have led to public health benefits. However, recent trends in ambient concentrations of particulate matter with diameters less than 2.5 μm (PM_2.5), a pollutant regulated under the Clean Air Act, have stagnated or begun to reverse throughout much of the USA. Here we use a combination of ground- and satellite-based air pollution data from 2000 to 2022 to quantify the contribution of wildfire smoke to these PM_2.5 trends. We find that since at least 2016, wildfire smoke has influenced trends in average annual PM_2.5 concentrations in nearly three-quarters of states in the contiguous USA, eroding about 25% of previous multi-decadal progress in reducing PM_2.5 concentrations on average in those states, equivalent to 4years of air quality progress, and more than 50% in many western states. Smoke influence on trends in the number of days with extreme PM_2.5 concentrations is detectable by 2011, but the influence can be detected primarily in western and mid-western states. Wildfire-driven increases in ambient PM_2.5 concentrations are unregulated under current air pollution law and, in the absence of further interventions, we show that the contribution of wildfire to regional and national air quality trends is likely to grow as the climate continues to warm.

DOI: 10.1038/s41586-023-06522-6

Source: https://www.nature.com/articles/s41586-023-06522-6