Pollution Characteristics and Factors Influencing the Reduction in Ambient PM 2.5 in Beijing from 2018 to 2020

• Published in: Huanjing kexue Vol. 44; no. 5; p. 2409
• Main Authors: Liu, Bao-Xian, Li, Qian, Sun, Rui-Wen, Dong, Rui, Wang, Shu-Xiao, Hao, Ji-Ming
• Format: Journal Article
• Language: Chinese
• Published: China 08.05.2023
• Subjects: Beijing; improvement in air quality; PM2.5 components; pollution characteristics; heating season
• ISSN: 0250-3301

Air quality data from 33 environment sites and five regional sites from 2018 to 2020, as well as meteorological data, were used to research PM variation,spatial and temporal change, diurnal variation, and heavy pollutions in Beijing. The annual average mass concentrations of PM in Beijing were 51, 42, and 38 μg·m , which showed great progress in air quality improvement. However, the PM concentration in 2020 was still 8.6% above the national limit value despite a 30.9% decline since 2017. The PM south-north gradient in Beijing remained throughout the three years, but this pattern showed a less significant trend. The highest monthly mean PM concentrations in Beijing tended to occur in January-March, with the lowest in August-September. NO , CO, and PM concentrations were significantly higher in the heating season than in the non-heating season by 58.4%, 52.9%, and 27.5%, respectively. Diurnal variation showed that greater PM concentrations were observed at nighttime during the heating season and, conversely, at