Kubait City, presents the second largest reduction of PM2.5 (42%).
•  The greatest PM2.5 reductions occurred in the capitals of America, Asia and Africa.

Main finding: 12% of PM2.5 reduction in the 50 most contaminated capitals cities of the world during the lockdown by COVID-19 and a the greatest PM2.5 reduction in a capital city was 57%.

1  Introduction
Currently, socio-ecological systems have a great impact on companies,