This is a double penalty for all those who breathe polluted air every day. Chronic exposure to air pollution would increase the risk of Covid-19, a disease resulting from infection with Sars-CoV-2.
This is at least what a new study suggests, published on January 10, 2022 in the journal Occupational & Environmental Medicine (Source 1).
The study was conducted among residents of the city of Varese, located in Lombardy, in northern Italy, a region hard hit by the pandemic. The researchers collected data on the exposure of the inhabitants to fine particles (PM2.5 being 2.5 micrometers in diameter, and PM10, 10μm), but also to nitrogen dioxide NO2, carbon monoxide nitrogen NO and ozone. Data they cross-checked with Sars-CoV-2 infection rates from the start of the pandemic through March 2021.
After taking into account age, gender and living in a nursing home (considered by researchers to be a risk factor for Covid-19), it turned out that PM2.5 and PM10 concentrations were significantly associated with an increased novel coronavirus infection rate.
In detail, the authors measured that each 1 µg/m3 increase in long-term PM2.5 exposure was associated with a 5% increase in the number of new Covid-19 cases, which equals 294 additional cases per 100,000 inhabitants/year. And applying seasonal rather than annual averages yielded similar results. High NO2 and NO concentrations were also associated with an increased risk of infection.
In a statement (Source 2), the scientists add that the associations observed here were even more visible among older participants, indicating a stronger effect of pollutants on the infection rate among 55-64 and 65-74 year olds. .
Since chronic exposure to air pollution increases the risk of respiratory and cardiovascular diseases, due to the inflammation generated and harming the immune system, it is quite possible that the same mechanisms are at play here.
Although more studies are needed to ensure the validity of this link between pollution and Covid-19, the authors call for strengthening the fight against air pollution, which leads to many illnesses and deaths.