[Simulation Analysis of the Impact of COVID-19 Pandemic Control on Air Quality in Henan Province based on Machine Learning Algorithm].

To reduce the risks of COVID-19 on society and the health of the general public, necessary prevention and control measures were implemented throughout China in 2020. Consequently, air quality was greatly improved due to lower emissions. However, the improvement of air quality could also be closely related to meteorological conditions.

[Evolution and Evaluation of O and VOCs in Zhengzhou During the National Traditional Games of Ethnic Minorities Period].

During the National Traditional Games of Ethnic Minorities (NTGEM) 2019, air quality in Zhengzhou was analyzed to evaluate the impact of pollution prevention and control measures on Zhengzhou. Ground-observed meteorological and pollutant data as well as the chemical compositions of volatile organic compounds (VOCs) were investigated. The results showed that the six parameters of pollutants in the safeguard period in 2019 indicated a downward trend as compared with that during the same time in 2018, and the average concentrations of PM and PM were decreased by 16.

[Heavy Metal Pollution Characteristics and Ecological and Health Risk Assessment of Atmospheric PM in a Living Area of Zhengzhou City].

To study the pollution characteristics of atmospheric heavy metal elements in a living area of Zhengzhou City, assess the potential ecological risks, and determine risks to resident health in this city, the Wuhan Tianhong TH-16A Airborne Particles Intelligent Sampler was used to collect atmospheric PM in Zhengzhou City. The mass concentrations of 17 metal elements were analyzed by ambient air determination of inorganic elements by ambient particle matter wavelength dispersive X-ray fluorescence spectrometry. The source of heavy metals was analyzed by the enrichment factor method and principal component analysis.