Lead author Dr. Allen Haddrell, Senior Research Associate in Aerosol Science at the University's School of Chemistry, said, "We knew SARS-CoV-2, like other viruses, spreads through the air we breathe. But this study represents a huge breakthrough in our understanding of exactly how and why that happens, and crucially, what can be done to stop it. "It shows that opening a window may be more powerful than originally thought, especially in crowded and poorly ventilated rooms, as fresh air will have a lower concentration of CO2, causing the virus to become inactivated much faster. "But it also highlights the importance of our global net zero goals because the research indicates even slightly raised levels of CO2, which are increasing in the atmosphere with the onset of climate change, can significantly improve the rate of virus survival and the risk of it spreading." During the COVID-19 pandemic carbon dioxide monitors were used to help estimate ventilation in buildings, as both CO2 and the virus are present in exhaled breath. But this research has uncovered how CO2 itself actually makes the virus survive longer in the air. The researchers also found that different SARS-CoV-2 variants had different aerostabilities, with the latest omicron variant having an extended lifespan. By varying the concentration of CO2 in the air between 400 parts per million (ppm)—the level in normal outdoor air) and 6,500 ppm, the team confirmed a correlation between increases in CO2 concentrations and the length of time airborne viruses remains infectious in air, compounding the risk of transmission. Results showed increasing the CO2 concentration to just 800 ppm, a level identified as well ventilated, resulted in an increase in viral aerostability. After 40 minutes, when compared to clean air, around 10 times as much virus remained infectious when the air had a CO2 concentration similar to that of a crowded room (3,000 ppm). Dr. Haddrell said,... |