Influence of transboundary air pollution on air quality in southwestern China

• Highest air pollution concentration mostly in winter or spring. O 3 peaked the afternoon while other pollutants had a bimodal pattern. Transboundary transport of from South Asia and Southeast Asia. Air is grand challenge our time due to its multitude adverse impacts on environment society, with scale more severe developing countries, including China. Thus, China has initiated implemented strict control measures over last several years reduce pollution. Monitoring data Jan 2015 Dec 2019 six criteria (SO 2 , NO CO, PM 2.5 10 ) at eight sites southwestern were investigated understand situation analyze transboundary this region. In terms seasonal variation, maximum concentrations these observed spring season depending individual site. For diurnal surface ozone pattern peaks morning late afternoon. There was limited domestic emissions sites. Local enhanced during some events. Mostly, associated high most Since can be transported long distances source regions, it necessary conduct research properly attribute quantify pollutants, which will provide solid scientific guidance for management