Impact of COVID-19 on the Yearly Concentration Reduction of Three Criteria Air Pollutants and Meteorological Parameters’ Effects on Aerosol Dispersion

The primary objective of this study is to evaluate the reduction percentage in the yearly concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2), and CO before and after COVID-19 in Amman, the capital city of Jordan, which has the highest population and traffic densities, and Zarqa, an industrial area with 55% of different types of industries. Additionally, this study examines the effect of metrological parameters such as temperature, humidity, and wind speed on air pollutant dispersion, particularly particulate matter 10 (PM10), which is considered uncontrollable. Furthermore, this study highlights the critical environmental and health effects of air pollution. The Ministry of Environment measured the yearly concentration of air pollutants (SO2, NO2, CO, and PM10) in three areas (Amman, Zarqa, and Irbid) in 12 stations in nearby industrial, urban, and traffic areas using the nitric oxide (NO) NO2 chemiluminescence analyzer Model 42i, hydrogen sulfide (H2S) and SO2 analyzer model 450iQ, and PM10 Peta Attenuation analyzer. The few air pollution studies in Jordan have primarily focused on average yearly concentrations of SO2, NO2, CO, and PM10 without considering the monthly or daily variations that greatly concern health and the environment. The results of the present study reveal that during the COVID-19 pandemic, there was a significant decrease in the annual concentrations of H2S, SO2, and NO2 as the reduction percentage in Amman 70, 58, 87% respectively, and in Zarqa 36, 62, 72% respectively. However, there is a slight reduction in CO and PM10 with 39 and 18% at Amman and 19% and 40% at Zarqa. This decrease is attributed to the reduction of primary sources of air pollutants, which are linked to the reductions in traffic volume and industrial activities during the lockdown. Furthermore, the results show that the Jordanian government has implemented regulations to address air pollution in residential areas. These regulations aim to prevent the burning of trees and smoking. The government is also adopting new transportation technologies to reduce the impact of CO2 and other pollutants produced by diesel and gasoline vehicles. The use of green fuels like synthetic natural gas, green methanol, or ammonia, as well as the increasing use of electric cars, are being encouraged. Implementing the bus rapid transit system, which started in 2021 and includes linked lines in the east and west areas of Jordan, has reduced the number of cars used and solved the main issues in crowded regions. Overall, the country has taken significant steps to address and control air pollution.