Exposure to air pollution could increase COVID-19 deaths

Long-term exposure to air pollution has been linked to an increased risk of dying from COVID-19.

For the first time, a study has estimated the proportion of deaths from the coronavirus that could be attributed to the exacerbating effects of air pollution for every country in the world.

The study, published in Cardiovascular Research, estimated that about 15 percent of deaths worldwide from COVID-19 could be attributed to long-term exposure to air pollution. In Europe the proportion was about 19 percent , in North America it was 17 percent, and in East Asia about 27 percent.

The researchers write in their paper that these proportions are an estimate of "the fraction of COVID-19 deaths that could be avoided if the population were exposed to lower counterfactual air pollution levels without fossil fuel-related and other anthropogenic—caused by humans—emissions".

They add that this "attributable fraction does not imply a direct cause-effect relationship between air pollution and COVID-19 mortality (although it is possible). Instead it refers to relationships between two, direct and indirect, i.e. by aggravating co-morbidities—other health conditions—that could lead to fatal health outcomes of the virus infection".

The research team includes Prof Jos Lelieveld, of the Max Planck Institute for Chemistry, Mainz, Germany, and the Cyprus Institute Nicosia, Cyprus, Professor Thomas Münzel, from the University Medical Center of the Johannes Gutenberg University, Mainz, and the German Center for Cardiovascular Research, Mainz, and Dr. Andrea Pozzer, from the Max Planck Institute for Chemistry.

The researchers used epidemiological data from previous US and Chinese studies of air pollution and COVID-19 and the SARS outbreak in 2003, supported by additional data from Italy. They combined this with satellite data showing global exposure to polluting fine particles known as 'particulate matter' that are less than or equal to 2.5 microns in diameter. The results are based on epidemiological data collected up the third week in June 2020.

Estimates for individual countries show, for example, that air pollution contributed to 29 pc of coronavirus deaths in the Czech Republic, 27 pc in China, 26 pc in Germany, 22 pc in Switzerland, 21 pc in Belgium, 19 pc in The Netherlands, 18 pc in France, 16 pc in Sweden, 15 pc in Italy, 14 pc in the UK, 12 pc in Brazil, 11 pc in Portugal, 8 pc in the Republic of Ireland, 6 pc in Israel, 3 pc in Australia and just 1 pc in New Zealand.

"When people inhale polluted air, the very small polluting particles migrate from the lungs to the blood and blood vessels, causing inflammation and severe oxidative stress. The damage to the inner lining of arteries leads to the narrowing and stiffening of the arteries. The COVID-19 virus also enters the body via the lungs, causing similar damage to blood vessels,” said Prof. Münzel.

"If both long-term exposure to air pollution and infection with the COVID-19 virus come together then we have an additive adverse effect on health, particularly with respect to the heart and blood vessels, which leads to greater vulnerability and less resilience to COVID-19. If you already have heart disease, then air pollution and coronavirus infection will cause trouble that can lead to heart attacks, heart failure and stroke."

“A lesson from our environmental perspective of the COVID-19 pandemic is that the quest for effective policies to reduce anthropogenic emissions, which cause both air pollution and climate change, needs to be accelerated. The pandemic ends with the vaccination of the population or with herd immunity through extensive infection of the population. However, there are no vaccines against poor air quality and climate change. The remedy is to mitigate emissions. The transition to a green economy with clean, renewable energy sources will further both environmental and public health locally through improved air quality and globally by limiting climate change," the authors conclude.