A high-resolution typical pollution source emission inventory and pollution source changes during the COVID-19...

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Public Health

Background:

• COVID-19 pandemic prompted national lockdown policies in China starting January 2020 to curb transmission.
• These restrictions led to significant alterations in population movement and industrial activity.
• Understanding the impact on air quality is crucial for public health and environmental policy.

Purpose of the Study:

• To quantitatively analyze the changes in air pollution sources in Shanghai during the COVID-19 lockdown.
• To establish a high-resolution emission inventory for key pollution sources.
• To provide a reference for assessing the impact of epidemics on emissions and informing regulatory actions.

Main Methods:

• Established a high-resolution emission inventory for stationary, mobile, and oil/gas sources in Shanghai.
• Utilized pollution source data from January to February 2020, comparing lockdown periods (P3) with pre-Spring Festival (P1).
• Quantitatively analyzed changes in emissions of sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), and volatile organic compounds (VOCs).

Main Results:

• Total emissions of SO2, NOx, PM, and VOCs were 9520.2, 37,978.6, 2796.7, and 7236.9 tons, respectively.
• Mobile sources experienced the largest decline; car mileage and oil sales decreased by ~80%, and aircraft activity by ~50%.
• Emissions of SO2, NOx, PM2.5, and VOCs decreased by 11%, 39%, 37%, and 47% during P3 compared to P1.

Conclusions:

• COVID-19 lockdown measures significantly contributed to substantial reductions in air pollutant emissions in Shanghai.
• Mobile sources were most affected, indicating their significant role in urban air pollution.
• The study provides valuable insights for other nations on managing air quality during public health crises.