美国麻省理工学院Steven R. H. Barrett小组的最新研究发现过早死亡与美国跨州空气污染有关。相关论文2020年2月12日在线发表在国际学术期刊《自然》上。

研究人员量化了美国相邻州之间空气污染的影响，并评估了其对过早死亡的贡献，该过早死亡与人类呼吸空气中细颗粒物（PM2.5）和臭氧的增加有关，这些增加的PM2.5和臭氧主要来自2005年至2018年的七个排放组分。平均而言，研究发现一个州内41%-53%空气质量相关过早死亡是由于另外其它州的排放造成的。研究还发现不同排放成分和化学物种类对跨州过早死亡的影响不同，以及这些变化随时间的变化。与总跨州影响相比，发电产生的排放物对其贡献最大，而商业/住宅排放的影响最小。

但是，自2005年以来发电排放物的减少意味着，到2018年，商业/住宅相关的跨州过早死亡是发电相关过早死亡的两倍。就排放化学物的种类而言，氮氧化物和二氧化硫是造成2005年跨州过早死亡的主要原因，但到2018年，跨州过早死亡主要是由PM2.5的排放造成的，其排放量是二氧化硫排放量的三倍。这项研究揭示了排放成分和排放物种类的变化对过早死亡的影响，这些变化可能有助于指导美国附近州空气质量的改善。

研究人员表示，室外空气污染对人类健康产生不利影响。据估计，空气污染造成过早死亡的人数约占美国年度过早死亡总数的5％至10％。各种能源燃烧产生的排放物，例如发电或道路交通，是空气中主要有害污染物（例如臭氧和PM2.5）的来源。过去减轻空气污染的重心主要集中在当地排放源与当地空气质量之间的关系上。空气质量也可能受到远距离排放源的影响，包括邻近州的排放。这种跨州污染为的监管带来了挑战。

附：英文原文

Title: Premature mortality related to United States cross-state air pollution

Author: Irene C. Dedoussi, Sebastian D. Eastham, Erwan Monier, Steven R. H. Barrett

Issue&Volume: 2020-02-12

Abstract: Outdoor air pollution adversely affects human health and is estimated to be responsible for five to ten per cent of the total annual premature mortality in the contiguous United States1,2,3. Combustion emissions from a variety of sources, such as power generation or road traffic, make a large contribution to harmful air pollutants such as ozone and fine particulate matter (PM2.5)4. Efforts to mitigate air pollution have focused mainly on the relationship between local emission sources and local air quality2. Air quality can also be affected by distant emission sources, however, including emissions from neighbouring federal states5,6. This cross-state exchange of pollution poses additional regulatory challenges. Here we quantify the exchange of air pollution among the contiguous United States, and assess its impact on premature mortality that is linked to increased human exposure to PM2.5 and ozone from seven emission sectors for 2005 to 2018. On average, we find that 41 to 53 per cent of air-quality-related premature mortality resulting from a state’s emissions occurs outside that state. We also find variations in the cross-state contributions of different emission sectors and chemical species to premature mortality, and changes in these variations over time. Emissions from electric power generation have the greatest cross-state impacts as a fraction of their total impacts, whereas commercial/residential emissions have the smallest. However, reductions in emissions from electric power generation since 2005 have meant that, by 2018, cross-state premature mortality associated with the commercial/residential sector was twice that associated with power generation. In terms of the chemical species emitted, nitrogen oxides and sulfur dioxide emissions caused the most cross-state premature deaths in 2005, but by 2018 primary PM2.5 emissions led to cross-state premature deaths equal to three times those associated with sulfur dioxide emissions. These reported shifts in emission sectors and emission species that contribute to premature mortality may help to guide improvements to air quality in the contiguous United States.

DOI: 10.1038/s41586-020-1983-8

Source: https://www.nature.com/articles/s41586-020-1983-8