Coronavirus: China Air Pollution Decline After COVID-19 Allied Shutdowns

A recent report says that China ranked the 11th most polluted country in the world, and 14 of its cities (14 of them), appeared on the world's highest polluted cities list.

Recently NASA published China images that show a substantial decrease in the amount of nitrogen dioxide (NO2) above China. The space agency considers that this decrease might be directly correlated to the factories closure and the economic slowdown that has happened due to COVID-19 spread.

As per the Earth Observatory, nitrogen dioxide is a poisonous gas emitted by industrial facilities, motor vehicles, and power plants.

The before and after images display an immense difference in the amount of NO2. Pictures clicked on 1-20 January 2020 (before) indicate a high concentration of NO2 density on the cities of Wuhan, Hong Kong, Beijing and Chongqing. In the pictures clicked from 10-25 February 2020, the quantity of the pollutants is almost negligible.

To curb the spread of COVID-19, China had carried out an unprecedented lockdown of the city of Wuhan, which was the central point of the virus breakout. City-wide isolations followed in other parts of the country also. Transportation to and from of cities, public gatherings, several offices, factories and industries were closed down.

As per a statement, NASA scientists confirmed that the decrease in NO2 pollution was first deceptive near Wuhan but ultimately spread across the country. Generally, there is a drop in NO2 during the Chinese Lunar New Year; meanwhile, many businesses shut shop to allow for the celebration. Though, scientists have never seen such a severe drop.

Fei Liu, an air quality researcher at NASA's Goddard Space Flight Center, said in the statement, "This year, the reduction rate is more significant than in past years, and it has lasted longer. I am not surprised because many cities nationwide have taken measures to minimize the spread of the virus."

The data was collected through ESA's Sentinel-5 satellite's Tropospheric Monitoring Instrument. A sensor on NASA's Aura satellite has also been capturing similar measurements.