The Covid-19 pandemic has raised the question of the most effective strategies to apply to limit the spread of viruses, which circulate in particular through the air we breathe.
On this subject, a study from the University of Bristol (United Kingdom) published in the journal Nature Communications on April 25 demonstrated a correlation between the concentration of CO2 in a room and the duration during which viruses suspended in the room The air remains infectious, reports New Atlas.
CO2 monitors
CO2 is an indirect indicator of the risk of viral transmission, since its concentration in the air varies depending on the ventilation of a room and the number of people there.
During the pandemic, CO2 monitors were therefore used. However, the concentration of CO2 linked to respiration has a direct influence on the pH of a room, which is itself a determining factor in the ability of an airborne virus to remain infectious. A more direct link could therefore be established.
An increase in their transmissibility
To do this, researchers from the University of Bristol studied the infectivity of the Delta, Beta and Omicron variants of Covid-19 inside several rooms in which the CO2 concentrations were different.
In this case, an increase in the CO2 concentration from 400 ppm (parts per million) to 800 ppm led to a significant increase in their transmissibility. On the other hand, no difference was noted at higher concentration thresholds.
Implications with global warming?
Therefore, “this relationship helped to understand why superspreading events can occur under certain conditions,” emphasized Allen Haddrell, lead author of the study.
In an environment concentrated in CO2, the droplets containing Covid see their pH reduced, which increases their duration of infectivity. This study therefore reinforces the recommendation that it is essential to ventilate a room well to reduce the risk of transmission of the virus.
Therefore, this correlation between CO2 and the lifespan of viruses could have implications linked to global warming. According to some climatologists, the concentration level of CO2 in the atmosphere could indeed increase from 400 ppm to 550 ppm in the coming decades. In other words: this phenomenon “could coincide with an increase in the transmissibility of other respiratory viruses,” said Allen Haddrell.
