Characters of Particulate Matter and Their Relationship with Meteorological Factors during Winter Nanyang 2021–2022.

The purpose of this study is to investigate the air quality levels of Nanyang city according to Chinese air quality standards. Therefore, in this study, fine particulate matter (PM_2.5), coarse particulate matter (PM₁₀), and total suspended particulate (TSP) were analyzed from 19 November 2021 to 19 March 2022 in Nanyang city. The results show that the average concentrations of PM_2.5, PM_10, and TSP were 106.47 µg/m³, 137.32 µg/m³, and 283.40 µg/m³, respectively. The numbers of days that meet the national secondary air quality standard of 24-h average concentrations were 29.75% for PM_2.5, 63.64% for PM₁₀, and 63.64% for TSP, indicating that most of the time, the air quality of Nanyang city remains polluted in winter, especially with more contributions of PM_2.5 compared to PM₁₀ and TSP. The higher concentrations were observed between 07:00 and 08:00, suggesting that vehicular emissions can be a major cause of air pollution in Nanyang city. The results also show a significant positive correlation between particulate matter and relative humidity, and a weak correlation with temperature and wind speed, which suggests that higher relative humidity increases the formation of particulate matter. This study can provide theoretical support for the local government to formulate air pollution prevention and control policies for Nanyang city. [ABSTRACT FROM AUTHOR]