研究发现，蒙古首都乌兰巴托年均可吸入颗粒物浓度为每立方米279微克，其后是又一个伊朗西部城市，萨南达杰，浓度为每立方米254微克。

The study found that the Mongolian capital Ulan Bator had an annual average PM10s density of 279 micrograms per cubic meter, followed by another west Iranian city, Sanandaj, with 254 micrograms.

youdao