Takeaway
Higher exposure to environmental pollutants (PM2.5, PM10, NO2) is a risk factor for severe COVID-19 (presence of pneumonia) in multiple sclerosis (MS) patients, and PM2.5 and NO2 are the biggest contributors of risk.
Why this matters
Air pollution has been linked to more severe COVID-19, leading to pneumonia in the general population as well as being associated with the incidence of MS and MS relapses.
Awareness of the health risks brought by modifiable factors such as air pollution exposure in at-risk populations should lead to measures to better safeguard them.