Covid patients exposed to air pollution suffered symptoms as if they were 10 years older, study finds

People exposed to air pollution before falling ill with Covid spent four days longer in hospital - the same amount of time as someone 10 years older, new research has found.

A Belgian study, published in the European Respiratory Journal (ERJ), shows that air pollution put an “even greater” burden on doctors, nurses and other healthcare workers during the pandemic.

It also showed that air pollution levels were linked to a 36% increase in the risk of needing intensive care treatment, while a separate study in Denmark found air pollution was linked to a 23% increase in the risk of death from Covid. In both of the studies the level of air pollution was below legal EU standards.

The new study found cleaner air brought health benefits that were as good as some of the medical treatments being used for Covid, highlighting the need to cut air pollution to reduce illness and deaths.

Professor Tim Nawrot, at Hasselt University in Belgium, said reducing air pollution “increases the health of the population and makes them less susceptible to future pandemics”.

He added: “The pandemic placed an enormous strain on doctors, nurses and other healthcare workers. Our research suggests that air pollution made that burden even greater.”

Previous research has already suggested that air pollution worsened Covid outcomes but it assessed groups of people together, whereas this recent study assessed individual patients, giving more confidence in the results.

Air pollution is known to be a major cause in aggravating respiratory diseases as it increases inflammation in the lungs and weakens immune defences.

Dr Zorana Jovanovic Andersen, at the University of Copenhagen, Denmark, and senior author of the Danish study, said the results “show how air pollution can compromise our immune system and leave us vulnerable.”

He said cutting air pollution “should be at the heart of preventive measures for current and future pandemics” and as a “strategy for dealing with seasonal influenza pandemics.”

The Belgian study assessed more than 300 patients who were hospitalised with Covid between May 2020 and March 2021. The levels of three pollutants, fine particles, nitrogen dioxide and soot, were gathered at the patients’ homes.

The amount of soot in the patients’ blood was also measured, while factors known to have an impact on the severity of Covid, such as age, sex and weight, were also taken into account.

The researchers found people exposed to a higher level of air pollution a week before being admitted to hospital spent about four more days in hospital.

The Danish study, also published in the ERJ, followed all 3.7 million people in the country, aged 30 or older, using Denmark’s national Covid surveillance system. It tracked them over the first 14 months of the pandemic and found that patients exposed to the higher level of small particle air pollution in 2019 were about 23% more likely to die from Covid.

Experts argue the findings show the need for governments to take action, even though the Covid global health emergency is now over.