空气污染是全球范围内很严重且日益增长的健康威胁，但在许多地区尚无实时空气质量数据。超过四分之三的美国外交使团都在细颗粒污染水平超过美国环境保护署（EPA）年度空气质量标准的地方。认识到这个问题后，北京美国大使馆于2008年安装了国务部的第一台空气质量监测器。如今，全世界已有超过二十多个使团装有空气质量监测器。到2018年底，这个数字将接近40。

Air pollution is a serious and growing health threat worldwide, yet in many areas, real-time air quality data is unavailable. More than three-quarters of U.S. diplomatic posts are in locations where fine particle pollution levels exceed the U.S. Environmental Protection Agency’s (EPA’s) annual air quality standard. Recognizing the problem, U.S. Embassy Beijing installed the Department’s first air quality monitor in 2008. Today, more than two dozen posts around the world have air quality monitors. By the end of 2018, that number will be near 40.

来源： 美国驻华大使馆