Air pollution linked to far higher Covid-19 death rates, study finds
8 Apr, 2020
Air pollution is linked to significantly higher rates of death in people with Covid-19, according to analysis.
The work shows that even a tiny, single-unit increase in particle pollution levels in the years before the pandemic is associated with a 15% increase in the death rate. The research, done in the US, calculates that slightly cleaner air in Manhattan in the past could have saved hundreds of lives.
Given the large differences in toxic air levels across countries, the research suggests people in polluted areas are far more likely to die from the coronavirus than those living in cleaner areas. The scientists said dirty air was already known to increase the risk of acute respiratory distress syndrome, which is extremely deadly and a cause of Covid-19-related deaths, as well as other respiratory and heart problems.
A separate report from scientists in Italy notes that the high death rates seen in the north of the country correlate with the highest levels of air pollution.
The scientists said their findings could be used to ensure that areas with high levels of air pollution take extra precautions to slow the spread of the virus and deploy extra resources to deal with the outbreak. Air pollution has already fallen because of widespread lockdowns, but the scientists said ensuring cleaner air in the future would help reduce Covid-19 deaths.
The study, by researchers at the Harvard TH Chan School of Public Health in Boston,analysed air pollution and Covid-19 deaths up to 4 April in 3,000 US counties, covering 98% of the population. “We found that an increase of only 1μg/m3 in PM2.5 [particles] is associated with a 15% increase in the Covid-19 death rate,” the team concluded.
A small increase in exposure to particle pollution over 15-20 years was already known to increase the risk of death from all causes, but the new work shows this increase is 20 times higher for Covid-19 deaths.
“The results are statistically significant and robust,” they said. The study took account of a range of factors, including poverty levels, smoking, obesity, and the number of Covid-19 tests and hospital beds available. They also assessed the effect of removing from the analysis both New York City, which has had many cases, and counties with fewer than 10 confirmed Covid-19 cases.
