Coronavirus: Areas with worse air pollution have ‘significantly higher’ death rates, study shows

Latest study on nitrogen dioxide reinforces earlier research linking air pollutants and Covid-19 deaths

Regions of the world which have higher air pollution tended to experience more deaths from Covid-19, a new study has found.

Geoscientist Yaron Ogen, from Martin Luther University of Halle-Wittenberg, examined data from satellites which track nitrogen dioxide in the air, a known pollutant which causes respiratory problems.

Dr Ogen then compared places which had been recorded as having high levels of nitrogen dioxide by a European Space Agency satellite in January and February with data on the numbers of people dying from the coronavirus.

There was a clear correlation between the two, the researcher wrote in a article published in the journal Science of the Total Environment.

“Since the novel coronavirus also affects the respiratory tract, it is reasonable to assume that there might be a correlation between air pollution and the number of deaths from Covid-19," he said.

Rather than just examining regions with high nitrogen dioxide levels alone, Dr Ogen also highlighted areas which had low amounts of vertical air exchange, which can also be measured by satellites.

Places where air is not being moved around tend to see more problems with air pollution, as pollutants remain closer to the ground and are breathed in more by locals.

Regions which experienced high numbers of coronavirus deaths did tend to have significant levels of nitrogen dioxide and low vertical air movement, Dr Ogen concluded.

“When we look at Northern Italy, the area around Madrid, and Hubei Provence in China, for example, they all have something in common: they are surrounded by mountains. This makes it even more likely that the air in these regions is stable and pollution levels are higher," he said.

The paper is just one of several studies which have linked coronavirus fatalities to air pollution.

Researchers at Harvard University in the United States analysed air pollution and deaths from Covid-19 across 3,000 counties in America and concluded even a tiny increase in fine-particulate pollution in the years before the pandemic even started led to a 15 per cent increase in death rates.

“It is likely that Covid-19 will be a part of our lives for quite a long time, despite our hope for a vaccine or treatment,” said Xiao Wu, one of the scientists behind the study. “In light of this, we should consider additional measures to protect ourselves from pollution exposure to reduce the Covid-19 death toll.”

A separate study by the Universities of Siena in Italy and Aarhus in Denmark pointed to air pollution as a possible factor behind northern Italy’s coronavirus death rates. The regions of Lombardy and Emilia Romagna had saw about 12 per cent of Covid-19 infections end in death, compared to just 4.5 per cent in the rest of the country.

Doctors and other experts say it is too early to draw firm conclusions about the effects of air pollution on the coronavirus pandemic, but some researchers are already using the growing evidence to warn countries with particularly polluted air to take additional precautions.

Ironically, the lockdowns imposed by most governments around the world are already causing a fall in air pollution, including nitrogen dioxide and fine particulates associated with Covid-19 deaths.

“Since there is no lower threshold for harm for most air pollutants, any improvement in air quality brings real health benefits,” observed Alastair Lewis, professor of atmospheric chemistry at the University of York.

“In the midst of a respiratory health crisis such as this, better air quality can only have a small effect, but it will undoubtedly be positive, relative to business as usual levels of pollution.”