The COVID-19 Outbreak Initially Improved Air Quality, Reduced Nitrogen Oxide and Carbon Emissions, and Later Reduced the Incidence of Respiratory Diseases in China

Abstract:

Because of the COVID-19 pandemic, Chinese lifestyle is Changing, even all the world. In the world outside Asia, the mask bias is eroding. Masks are often an option for people to travel during the smoggy winter months in China, but now they are worn to prevent infection. Class C infections include influenza and hand-foot-and-mouth disease mainly, so category C infectious diseases are used to represent the effect of wearing masks and washing hands frequently to reduce the spread of respiratory and hand-foot-mouth infectious diseases. Datasets of the Chinese Public Health Science Data Center were analyzed, the change rates of class C infections in January, February, March, April, May and June 2020 compared to the same month in 2018 are 1.29, -0.58, -0.78, -0.67, -0.92, -0.98. Air quality affects human health. It is necessary to reduce sulfate levels in highly polluted haze-fog conditions, co-control of SO₂ and NO_x emissions. 129 days home quarantine and travel restrictions made a scenario to improve China's air quality. The reduced emission of nitrous oxide by cars (506,883~549,241) tons were estimated. Datasets of Monthly Report of Urban Air Quality Status from Ministry of Ecology and Environment of the People’s Republic of China were analyzed, the rates of change of SO₂ monthly in 2020 compared with 2018 minus the year-on-year decrease in 2020 compared with 2019 are -0.18, -0.11, -0.17, -0.15, 0, -0.22. For NO₂, they are -0.03, -0.10, -0.11, -0.19，-0.11, -0.10. Those of PM_2.5 are 0.24, 0.16, -0.07, -0.10, -0.11, -0.17. As to PM10, they are 0.19, 0.05, -0.03, -0.22, -0.04, -0.16. Those of CO-95per are 0.34, 0.11, -0.11, -0.07, -0.18, -0.10. Those of O₃-8H-90per are -0.32, -0.25, -0.24, -0.12, 0.30, -0.15. Among them, the correlations between the change rates of class C infections and PM_2.5, CO-95per and PM₁₀ for the same times are better, R² are 0.89, 0.83 and 0.71, respectively. COVID-19 also temporarily slow down climate warming and reduced 3.01 Gigatons Carbon emission. However, with the global work resumption, perhaps as the economy recovers, NO_x and carbon emissions will return to their previous levels or even rise. With the melting of polar glaciers and the burning of permafrost, human beings live on a hot earth. It is hoped that lessons can be learned to protect biological habitats and save energy and reduce NO_x and Carbon emissions.