The presence of high level of toxic nitrogen dioxide in the air can be linked with a high number of mortality from Covid-19, researchers have said as they found that areas with permanently high levels of pollution have significantly more deaths than other regions.
The results published in the latest issue of journal ‘Science of the Total Environment’ inferred that persistent air pollution in the affected regions could have led to overall poorer health in the people living there, making them particularly susceptible to the virus which has infected over 24 lakhs people and claimed 1.65 lakhs lives so far.
It is known that nitrogen dioxide is an air pollutant that damages the human respiratory tract causing many types of respiratory and cardiovascular diseases in humans.
"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," said Dr Yaron Ogen from the Institute of Geosciences and Geography at Martin Luther University Halle-Wittenberg (MLU).
He combined three sets of data. This included the levels of regional nitrogen dioxide pollution measured by the European Space Agency's (ESA) Sentinel 5P satellite, which continuously monitors air pollution on earth.
Based on this data, he produced a global overview for regions with high and prolonged amounts of nitrogen dioxide pollution.
"I looked at the values for January and February of this year, before the corona outbreaks in Europe began," explained Ogen. He combined this data with statistics from the US weather agency NOAA on vertical air flows.
His premise: If air is in motion, the pollutants near the ground are also more disseminated. However, if the air tends to stay near the ground, this will also apply to the pollutants in the air, which are then more likely be inhaled by humans in greater amounts and thus lead to health problems.
Using this data, the researcher was able to identify hotspots around the world with high levels of air pollution and simultaneously low levels of air movement.
He then compared these with the data on deaths related to Covid-19, specifically analysing the data from Italy, France, Spain and Germany.
It turned out that the regions with a high number of deaths also had particularly high levels of nitrogen dioxide and a particularly low amount of vertical air exchange.
"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," Ogen added.
"However, my research on the topic is only an initial indication that there might be a correlation between the level of air pollution, air movement and the severity of the course of the corona outbreaks," he said.
Earlier, researchers at Harvard University in the US found that even a small increase in long-term exposure to PM2.5, or particulate matter with a diameter of 2.5 micrometers or less, can lead to a large increase in the death rate from Covid-19.