These Cities Now Have Less Air Pollution During Virus Lockdowns

Restrictions on travel and non-essential business over the past weeks to control the spread of Covid-19 have meant dramatically cleaner air for some of the world’s most polluted cities. 

Seven global cities including Delhi, Seoul, Los Angeles, and New York, experienced 25% to 65% reduction in fine particulate matter or PM2.5 air pollutants during the lockdown, according to a report by IQAir.

Major Cities See Decrease in PM2.5 During Covid-19 Lockdown

Percent change for a three-week period in 2020 compared to same period in 2019

Note: Lockdown dates are from Mar. 23-Apr. 13, except for Seoul (Feb. 26- Mar. 18) and Wuhan (Feb. 3- Feb. 24).

Cities with historically high PM2.5 concentration levels showed the most substantial reductions in air pollution.

Indian city Delhi, which ranked as the fifth most polluted city and the most polluted capital in 2019, saw a 60% drop in air pollution. Indian Prime Minister Narendra Modi restricted the movement of 1.3 billion people—implementing curfews, sealing borders, shutting down businesses and suspending public transport across the country.

Daily PM2.5 level for a three-week period in 2020 compared to the same period in 2019

Note: Data shows concentration of PM2.5 in micrograms per cubic meter air. Lockdown date for Delhi is from Mar. 23-Apr. 13, Feb. 26- Mar. 18 for Seoul and Feb. 3- Feb. 24 for Wuhan. No Feb. 29, 2019 data for Seoul.

Seoul in South Korea saw a 54% decrease in air pollution as the government responded to the rapidly increasing coronavirus cases in the country. The city was not put in strict lockdown like some other countries, but they implemented social distancing measures, contact tracing, and companies asked their employees to work from home.  

Wuhan, the Chinese city in the epicenter of the Covid-19 outbreak, was put in a 10-week lockdown, keeping 11 million residents in their homes and shutting down manufacturing facilities. During the defined 3-week peak lockdown period, Wuhan’s PM2.5 level went down 44% from 2019. 

Daily PM2.5 level from Mar. 23- Apr. 13, 2020 compared to the same period in 2019

Note: Data shows concentration of PM2.5 in micrograms per cubic meter air.

Delhi’s air quality level during the lockdown period shows a 55% decrease compared to the average pollution level during the same period for the past four years. Wuhan’s smaller decrease from 2019 reflects the Chinese government’s efforts to reduce air pollution—but looking at the four-year average for the same three-week period, the city sees a 50% reduction in fine particulate matter. 

Other Major Cities With Improved Air Quality

Average PM2.5 level for the three-week lockdown period in 2020 compared to the same period in 2016-2019

Note: Data shows concentration of PM2.5 in micrograms per cubic meter air. Lockdown dates are from Mar. 23-Apr. 13, except for Seoul (Feb. 26- Mar. 18) and Wuhan (Feb. 3- Feb. 24).