Living in areas with higher levels of air pollution is associated with an increased risk of death from COVID-19, claims a study conducted in the US. The research is the first to look at the link between long-term exposure to fine particulate air pollution generated largely from fuel combustion from cars, refineries, and power plants -- and the risk of death from COVID-19 in the US, said the researchers from Harvard T H Chan School of Public Health.

The yet-to-be-published study looked at more than 3,000 counties across the US, comparing levels of fine particulate air pollution with novel coronavirus death counts for each area. The researchers adjusted for population size, hospital beds, number of people tested for COVID-19, weather, and socioeconomic and behavioural variables such as obesity and smoking. They found that a small increase in long-term exposure to PM 2.5 leads to a significant increase in the COVID-19 death rate. The study found, for example, that someone who lives for decades in a county with high levels of PM 2.5 is 15 per cent more likely to die from COVID-19 than someone who lives in a region that has just one microgramme per cubic metre less pollution.

The findings align with known connections between PM 2.5 exposure and higher risk of death from many other cardiovascular and respiratory ailments, said the researchers. "A small increase in long-term exposure to PM 2.5 leads to a large increase in COVID-19 death rate, with the magnitude of increase 20 times that observed for PM 2.5 and all-cause mortality," according to the researchers. "The study results underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis," they said.