80 Percent of COVID-19 Deaths in These European Countries Were in Areas With High Levels of Air Pollution

An Israeli researcher has found a link between high COVID-19 fatality rates in four European countries and significant levels of nitrogen dioxide (NO2) pollution.

Yaron Ogen, a postdoctoral researcher in the Institute of Geosciences and Geography at Martin Luther University of Halle-Wittenberg, Germany, says the results could indicate that long-term exposure to this pollutant may play an important role in deaths resulting role from the virus, according to a study published in the journal Science of The Total Environment.

Nevertheless, Ogen only identified a strong correlation between these factors, and more research will be required to determine whether there is a direct causal link between NO2 pollution and a higher risk of death from COVID-19.

Nitrogen dioxide is a gas emitted by both natural processes and human sources, such as vehicle traffic and industrial activity. Long-term exposure to NO2 has been linked to a wide range of severe health problems, such as hypertension, diabetes, and cardiovascular diseases.

Many of the health problems that result from long-term exposure to air pollutants are the same as those that increase the risk of death from COVID0-19, given that it is a respiratory disease.

For his latest study, Ogen wanted to look at the relationship between long-term exposure to NO2, which in this paper was defined as a two-month period (between January and February) prior to the outbreak of COVID-19 in Europe, and fatality from the novel coronavirus.

"When the pandemic started and reached Europe, I saw a pattern," Ogen told Newsweek. "I noticed that the distribution of fatality was not equal, and it concentrated mostly in north Italy, Madrid, Wuhan, and Tehran. Then I asked one simple question: what all these areas have in common? As a geographer, I was familiar with the topography and the regions and I just connected the dots which leads me to the assumption that there might be a connection to air pollution."

To do this, the researcher examined data collected by the European Space Agency's Sentinel-5P satellite, which can map the distribution of NO2 in the lowest layer of the Earth's atmosphere, as well as information on the number of COVID-19 fatalities taken from 66 administrative regions in Italy, Spain, France and Germany.

Ogen identified 4,443 deaths in these four countries as of March 19: 78 percent of which occurred in five regions located in northern Italy and central Spain. These regions include Lombardy, Emilia-Romagna, Piedmont, and Veneto in Italy; and the Community of Madrid in Spain.

Furthermore, Ogen found that these same five regions had the highest concentrations of nitrogen dioxide out of the areas studied. He also noted that these regions exhibited poor airflows, the Community of Madrid and parts of northern Italy are surrounded by mountain ranges, for example, meaning that air pollution is not easily dispersed.

Venice, Italy
Panoramic view of Piazza San Marco on April 19, 2020 in Venice, Italy. Pietro D'Aprano/Getty Images

"These results indicate that the long-term exposure to this pollutant [NO2] may be one of the most important contributors to fatality caused by the COVID-19 virus in these regions and maybe across the whole world," Ogen wrote in the paper.

According to the researcher, these geographic conditions and significant concentrations of NO2 can lead to a high incidence of respiratory problems and lung inflammation in these populations.

"This chronic exposure could be an important contributor to the high COVID-19 fatality rates observed in these regions. As earlier studies have shown that exposure to NO2 causes inflammatory in the lungs, it is now necessary to examine whether the presence of an initial inflammatory condition is related to the response of the immune system to the coronavirus," Ogen wrote in the study.

"Hence, poisoning our environment means poisoning our own body and when it experiences a chronic respiratory stress, its ability to defend itself from infections is limited," he said.

Given that urban centers in northern Italy and central Spain have been the worst hit areas of Europe in terms of the number of coronavirus cases, it might be expected that they would have the highest fatality rates. However, Ogen said that before he started analyzing the results, he also checked other factors such as population and population density and no connection was found.

"For example, as of April 22, 2020, the region of Lazio, Italy with 5.9 million inhabitants—where Rome is located—had 370 confirmed deaths while the region of Piedmont in north Italy with 4.5 million inhabitants had 2,559 death cases. However, more studies should be conducted on this."

In light of his results, Ogen stressed that more research is needed to determine the extent to which different factors, such as age and the presence of pre-existing conditions, in addition to NO2 pollution may contribute to COVDI-19 fatality rates.

"This was only a preliminary work, and there is a lot more to do. Other pollutants should be considered such as PM2.5 and Ozone. In addition, more studies should be conducted using higher resolutions, and check differences between neighborhoods, residents living near main roads and combine it with in-situ measurements," Ogen said.

"The environmental factors and their impact on our health should always be considered and maybe this will change the way we plan and build our cities," he said.

Another recent study submitted to The New England Journal of Medicine, found that people in the United States living in areas with high levels of air pollution may be at an increased risk of death from COVID-19.

But instead of looking at nitrogen dioxide specifically, this study examined the relationship between COVID-19 deaths and long-term exposure to PM2.5—tiny inhalable particles measuring 2.5 micrometers or smaller.

This article was updated to include additional comments from Yaron Ogen.