A Harvard University study shows that an increase of only one microgram per cubic metre in PM 2.5 – dangerous tiny pollutants in the air – is associated with an 8% increase in the Covid-19 death rate. Another study by scientists at the UK’s University of Cambridge also found a link between the severity of Covid-19 infection and long-term exposure to air pollutants, including nitrogen oxides and ground-level ozone from car exhaust fumes or burning of fossil fuels.
source: bbc.com