Pollution levels exceeding air quality standards for more than 100 days a year raises Covid-19 infection risk three-fold.
The study from Italy measured pollution in terms of days per year when PM10 or Ozone exceeded safe standards.
People with respiratory diseases like asthma and COPD are at higher risk of coronavirus infection and complications.
An earlier study from Italy also linked air pollution with higher rates of Covid-19 deaths.
One in eight deaths in India in 2017 were linked to air pollution, according to the health ministry.
We need data for India linking coronavirus infections and deaths.