Impact of two epidemic control on air quality characteristics in Shijiazhuang City

ABSTRACT

Studies have shown that during the 2020 epidemic control period, air quality data has been"abnormal", but due to differences in geography and demographic factors, the survey results in different regions are not consistent. The purpose of the study is to analyze the difference in air quality under the control of the two epidemics in Shijiazhuang City, further explore the impact of control measures on air quality, and provide reference and ideas for improving air quality and adjusting atmospheric control measures. Based on the China Air Quality Online Monitoring and Analysis Platform and Zhenqi.com, with Shijiazhuang air quality as the research object, the air quality and meteorological monitoring data in the past 6 years have been collected and sorted, and the t-test and rank-sum test methods are used to analyze the air pollution status and change characteristics in the two epidemic control periods based on the air quality monitoring data of Shijiazhuang City during the epidemic control period from January 5 to February 8,2021, with comparison with the data of the same time period in 2019. With reference to changes in meteorological factors, the impact of epidemic control on air quality was comprehensively analyzed. Results indicate that in 2021, the social blockade measures against the epidemic have greatly reduced the concentrations of various pollutants. The concentrations of PM2.5,PM10,SO2,CO2, and NO2 have dropped by 52.13%,40.62%,74.93%,55.53%,44.59%,(p<0.05),respectively, compared with the same period before the epidemic (2016-2019 average levels).O3 pollution increased, and the concentration increased by 49.40%compared to before the epidemic (p<0.05);the severity of epidemic control measures also has a certain impact on air quality compared with the epidemic blockade carried out in the same period in 2020.PM2.5,PM10,CO2,and NO2 during the epidemic control period in 2021 decreased by 54.85%,37.79%,52.36%and 31.15%,respectively,(p<0.05). Analysis of meteorological factors showed that there was no significant difference in the average temperature and wind speed in Shijiazhuang during the survey period from January 5 to February 8 in the past 6 years. Compared with before the epidemic, there was no significant change in the relative humidity during the epidemic period in 2021. The relative humidity in the same period in 2020 was 65.28% higher than before the epidemic (p<0.05). There were obvious differences in air quality during the two epidemic control periods in Shijiazhuang, but the meteorological factors did not show corresponding changes. The change in air quality may be related to the strictness of the epidemic control measures and the order of implementation.