[Impact of Pollutant Emission Reduction on Air Quality During the COVID-19 Pandemic Control in Early 2020 Based on RAMS-CMAQ].

In this work, the relationships between air quality and pollutant emissions were investigated during the COVID-19 pandemic in Shandong Province. During the quarantine period (from January 24 to February 7, 2020), the concentrations of atmospheric pollutants decreased significantly relative to the period before controls were imposed (from January 15 to 23, 2020). Specifically, except for an increase in the concentration of O, concentrations of PM, PM, NO, SO, and CO decreased for 72.

[Characteristics and Sources Apportionment of Fine Particulate Matter in a Typical Coastal City During the Heating Period].

To clarify the pollution characteristics and sources of PM in Weihai during the heating period, PM samples from ambient air were collected at three routine air quality monitoring sites from January to March 2018. The OC, EC, water-soluble ions, and elements in PM were analyzed, and the sources of PM were identified using the PMF model. The results showed that the average daily mass concentration of PM was (33.