Millions of people at greater risk of catching COVID-19 due to air pollution

By Tom Campbell via SWNS

Millions of people could be at greater risk of caching COVID-19 because of air pollution, warns a new study.

Places where pollution levels rise by one millionth of a gramme could also see infection rates jump five percent, say scientists.

Several reasons have been put forward to explain why some areas like Lombardy in Northern Italy fared so badly in terms of COVID-19 cases and deaths during the pandemic.

But while air pollution has been linked with COVID-19 infection rates, design flaws and limited data have scuppered research efforts until now.

The study, conducted by Professor Giovanni Veronesi at the University of Insubria in Italy was published in the BMJ.

Professor Veronesi said: "Our findings provide the first solid empirical evidence for the hypothesised pathway linking long-term exposure to air pollution with the incidence of COVID-19, and deserve future generalisation in different contexts.

"Meanwhile, government efforts to further reduce air pollution levels can help to mitigate the public health burden of COVID-19.”

Most of the 3.9 million Europeans who live in places where air pollution has exceeded official limits are in Northern Italy, according to the European Union Environmental Agency.

The researchers looked at long-term pollution levels and COVID-19 infections in Varese, the eighth-largest city in Lombardy.

Levels of pollution exposure for more than 97 percent of the city's 81,543 residents were calculated by the researchers based on their home address.

Annual and seasonal averages for the five main pollutants over a 40-kilometre (24.8 mile) area were analysed, including types of particle pollution - PM2.5 and PM10, nitrogen dioxide (NO2), nitric oxide (NO) and ozone (O3).

The researchers then reviewed 4408 new COVID-19 cases, which were registered between 25 February 2020 and 13 March 2021.

Official figures show that only 3.5 per cent of the population in the entire region were fully vaccinated by the end of March 2021.

Pollution levels were linked to an increase in COVID-19 infections the researchers found after accounting for other factors such as age, gender and long term health conditions.

An increase of one µg/m3 (millionth of a gramme per cubic metre) in long term exposure to PM2.5 saw infections rise by 5 percent, equivalent to 294 extra cases per 100,000 people a year.

Applying seasonal rather than annual averages yielded similar results, even after excluding care home residents and adjusting for other factors such as local levels of deprivation and using public transport.

Similar findings were observed for the other types of pollution - PM10, nitrogen dioxide and nitric oxide.

The link between pollution and higher COVID-19 infections was particularly strong among older age groups, the researchers found.

Taking medication for diabetes, high blood pressure, respiratory diseases and heart problems also increased the risk of COVID-19 infection by 17 percent, 12 percent, 17 percent and 29 percent respectively.

Professor Veronesi said: "Long term exposure to air pollution heightens the risk of respiratory and cardiovascular diseases through persistent inflammation and compromised immunity.

"These same pathways may therefore be involved in the link between air pollution and higher COVID-19 infection rates."

The findings were published in the journal Occupational & Environmental Medicine.