London – New research adds to the growing body of evidence that elevated levels of air pollution may amplify the waves of SARS-CoV-2 contamination, the virus responsible for Covid-19 diseases.
The study, published in the journal Earth Systems and Environment, investigated possible interactions between acutely elevated levels of fine particulate matter and the virulence of the coronavirus disease.
The result suggests that high concentrations of particles less than 2.5 micrometres in size may modulate, or even amplify, the waves of SARS-CoV-2 contamination and explain in part the particular profile of the Covid-19 pandemic.
“The study provides preventive measures related to air pollution to limit future outbreaks of morbidity and mortality due to the coronavirus,” said study author Mario Rohrer from the University of Geneva in Switzerland.
Covid-19 studies conducted in Italy and France suggest that SARS-CoV-2 was already present in Europe at the end of 2019, while the sharp increase in morbidity and mortality was only recorded in spring 2020 in Paris and London.
“This time lag is surprising, but also suggests that something else than just the mere interaction of people may promote the transmission of the virus, and particularly the severity of the infection,” Rohrer said.
The research team has been able to show that these increases in cases followed phases where the levels of fine particles in the air were higher.
The team made similar observations in the Swiss canton of Ticino, where fine-particle pollution increased sharply during a period of shallow fog on the Magadino plain and the Sotto Ceneri, observed at the end of February 2020.
The findings showed that acute concentrations of fine particles, especially those smaller than 2.5 micrometres, cause inflammation of the respiratory, pulmonary and cardiovascular tracts and thicken the blood.
“In combination with a viral infection, these inflammatory factors can lead to a serious progression of the disease. Inflammation also promotes the attachment of the virus to cells,” Rohrer said.
Nonetheless, the researchers also emphasize that, although particulate matter pollution can influence the virulence of the virus and possible severe disease progression, physiological, social or economic factors will clearly also influence the further course of the pandemic.
“This study offers the possibility of taking preventive measures in the event of future increases in fine particulate matter concentrations, thus limiting a new flare-up of Covid-19 morbidity and mortality,” the team noted.