Abstract Air pollution is one of the most persistent environmental issues in South America, with exposure to air pollutants being associated with increased mortality and morbidity. According to estimates of the World Health Organization (WHO), in 2016, 91 % of the global population lived in cities that exceeded the WHO PM2.5 annual guideline (10 μg/m3). In Latin America and the Caribbean, other studies affirm that approximately 100 million people are exposed to poor air quality, exceeding WHO guidelines. This study presents a review of long-term (annual) and short-term (daily) concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter (PM10 and PM2.5), carbon monoxide (CO), and ozone (O3), collected between 2010 and 2017 by the automatic monitoring networks of 11 metropolitan areas of South America, including three of global 33 megacities (Rio de Janeiro, Sao Paulo, and Buenos Aires), and three from all 34 largest cities in the world (Bogota, Lima, and Santiago). Despite efforts to monitor air quality, in some cities, the information on air quality provided by environmental authorities still has poor publicity and presentation, making it difficult to take action for critical air pollution episodes. Annual particulate matter (PM2.5 and PM10) monitored in all cities (2010-2017) exceeded the World Health Organization Air Quality Guidelines (WHO-AQG). The annual NO2 guideline was exceeded at least in one city between 2010 and 2017, except in 2014. Most average daily concentrations of SO2 in South America were below the WHO-AQG. Still, Vitoria, Rio de Janeiro, and Belo Horizonte Metropolitan Areas presented values over WHO guidelines, and for the two last cities, over intermediate standards of Brazilian national legislation. Most of the ozone concentration (8 -h running average) was below WHO-AQG, but Rio de Janeiro, Sao Paulo, and Belo Horizonte presented exceedances of this limit between 2010 and 2017. Although some cities in South America have their pollutant concentrations reduced since 2010 (PM2.5, for example), such as Sao Paulo, Vitoria, and Bogota, the region does not report a trend in the same direction, with the WHO guidelines and national or local standards being continuously exceeded.

中文翻译：

---

南美大城市空气质量现状及趋势

摘要 空气污染是南美洲最持久的环境问题之一，接触空气污染物会增加死亡率和发病率。据世界卫生组织（WHO）估计，2016 年，全球 91% 的人口居住在超过 WHO PM2.5 年度指南（10 μg/m3）的城市。在拉丁美洲和加勒比地区，其他研究证实，大约有 1 亿人暴露在空气质量差的环境中，超出了世卫组织的指导方针。本研究回顾了二氧化氮 (NO2)、二氧化硫 (SO2)、颗粒物（PM10 和 PM2.5）、一氧化碳 (CO) 和2010 年至 2017 年间由南美洲 11 个大都市区的自动监测网络收集的臭氧 (O3)，包括全球 33 个特大城市中的三个（里约热内卢、圣保罗和布宜诺斯艾利斯），以及世界上所有 34 个最大城市中的三个（波哥大、利马和圣地亚哥）。尽管开展了空气质量监测，但在一些城市，环保部门提供的空气质量信息宣传和展示效果仍然不佳，导致对严重的空气污染事件难以采取行动。所有城市（2010-2017 年）监测到的年度颗粒物（PM2.5 和 PM10）均超过了世界卫生组织空气质量指南（WHO-AQG）。除 2014 年外，2010 年至 2017 年期间至少有一个城市超过了年度二氧化氮指南。南美洲大部分二氧化硫的日均浓度低于 WHO-AQG。尽管如此，维多利亚、里约热内卢和贝洛奥里藏特都市区的价值高于世卫组织的指导方针，对于最后两个城市，超过了巴西国家立法的中间标准。大部分臭氧浓度（8 小时运行平均值）低于 WHO-AQG，但里约热内卢、圣保罗和贝洛奥里藏特在 2010 年至 2017 年期间超过了这一限值。 尽管南美一些城市的污染物浓度有所降低自 2010 年以来（例如 PM2.5），如圣保罗、维多利亚和波哥大，该地区并没有出现相同方向的趋势，不断超过 WHO 指南和国家或地方标准。