Rupakheti, Dipesh, Yin, Xiufeng, Rupakheti, Maheswar, Zhang, Qianggong, Li, Ping, Rai, Mukesh, and Kang, Shichang
To understand the characteristics of particulate matter (PM) and other air pollutants in Xinjiang, a region with one of the largest sand-shifting deserts in the world and significant natural dust emissions, the concentrations of six air pollutants monitored in 16 cities were analyzed for the period January 2013–June 2019. The annual mean PM 2.5 , PM 10 , SO 2 , NO 2 , CO, and O 3 concentrations ranged from 51.44 to 59.54 μg m−3, 128.43–155.28 μg m−3, 10.99–17.99 μg m−3, 26.27–31.71 μg m−3, 1.04–1.32 mg m−3, and 55.27–65.26 μg m−3, respectively. The highest PM concentrations were recorded in cities surrounding the Taklimakan Desert during the spring season and caused by higher amounts of wind-blown dust from the desert. Coarse PM (PM 10-2.5) was predominant, particularly during the spring and summer seasons. The highest PM 2.5 /PM 10 ratio was recorded in most cities during the winter months, indicating the influence of anthropogenic emissions in winters. The annual mean PM 2.5 (PM 10) concentrations in the study area exceeded the annual mean guidelines recommended by the World Health Organization (WHO) by a factor of ca. ∼5–6 (∼7–8). Very high ambient PM concentrations were recorded during March 19–22, 2019, that gradually influenced the air quality across four different cities, with daily mean PM 2.5 (PM 10) concentrations ∼8–54 (∼26–115) times higher than the WHO guidelines for daily mean concentrations, and the daily mean coarse PM concentration reaching 4.4 mg m−3. Such high PM 2.5 and PM 10 concentrations pose a significant risk to public health. These findings call for the formulation of various policies and action plans, including controlling the land degradation and desertification and reducing the concentrations of PM and other air pollutants in the region. Image 1 • SO 2 , PM 2.5 and CO concentration decreased during 2015–2018. • Proximity to deserts results in dominance of coarse PM in spring and summer. • Ambient PM 2.5 and PM 10 concentrations frequently exceeded guideline values. [ABSTRACT FROM AUTHOR]