Pollution and Covid-19. Do we need more notices?

On June 7, 2020 we published this article in Pirates Verds, written by the way in early May of the same year. Little could we imagine then that today, after more than a year of its publication, the virus would continue to infect, out of control, all of humanity, and that vaccines would only dampen its severity, and not in all cases.

In March of last year, the European Herat Journal, attached to the University of Oxford, updated the annual number of estimated premature deaths from air pollution in the world. According to new and more adjusted measurement systems, the number of human beings killed by the poor quality of the air we breathe goes from 4.5 million a year to almost 8.8 million, almost 800,000 of those deaths occur in continental Europe. Particularly harmful are suspended particles of less than 2.5 microns (PM 2.5). To give you an idea, they are 100 times thinner than the thickness of a human hair. One micron is equal to one thousandth of a millimeter. PM 2.5 particles are of anthropogenic origin in almost all cases, that is, produced exclusively by humans.

To analyze the effects of these particles in suspension on animal health, which includes human health, we must distinguish between PM 10 (less than 10 microns), which may have a natural origin, and PM 2.5, whose origin is human emissions, mainly from diesel engines. PM 2.5 are lighter and remain in the air longer than the previous ones, causing or, at least, exacerbating various respiratory diseases, such as pneumonia, bronchitis, asthma, allergies and cardiovascular ailments.
Taking into account that pollution, mainly that of large urban centers, causes millions of deaths worldwide, and triggers or worsens respiratory and cardiovascular diseases, is it an added risk factor during the current pandemic caused by COVID -19, which also causes serious respiratory and cardiovascular effects in a part of the population?
Based on several studies on the subject carried out during this pandemic, it seems that it is true, but with nuances.

A study led by doctoral student Marco Travaglio and his Cambridge University colleagues overlapped the levels of nitrogen dioxide (NO2) and nitrogen oxide (NO) from more than 120 monitoring stations in England, with figures on infections and coronavirus deaths; finding a link between poor air quality and COVID-19 case fatality in those areas. Travaglio stated that he needs further work to show the specific cause of this correlation, but assured that the health conditions caused by air pollution are remarkably similar to those that increase vulnerability to this coronavirus.

Similar work by Dr. Yaron Ogen of Germany’s Martin Luther Halle-Wittenberg University mapped airborne NO2 levels and COVID-19 deaths regionally in Italy, Spain, France, and Germany; finding that long-term exposure to air pollution “could be a major contributor” to high mortality rates.

Another team, led by Dario Caro, Ph.D. in chemistry specializing in environmental sciences, from Aarhus University in Denmark, analyzed the correlation between air pollution and coronavirus infections and deaths in northern Italy. His team found that people living in areas with more polluted air had a higher level of inflammatory cytokine cells, making them more vulnerable to the virus.

Another study, more complete than the previous ones, carried out by doctoral student Xiao Wu and assistant professor Rachel C. Nethery, together with Biostatistics professor Francesca Dominici and other colleagues also from Harvard University, found that small increases in exposure at long-term levels of small particles in suspension, are related to a great jump in the death rate from COVID-19. Each additional microgram of fine particles per cubic meter to which people were exposed in the long term was associated with an 8% increase in the death rate. This study analyzed deaths from COVID-19 from more than 3,000 counties in the United States (representing 98% of the population) until April 22, 2020, at the Johns Hopkins University Center for Systems Science and Engineering of the Coronavirus Resource Center.
They found that an increase of just 1 μg / m3 of PM2.5 is associated with an 8% increase in the COVID-19 mortality rate, with a 95% confidence interval, and a positive and negative variability of 2%. – 15%. The results were statistically significant and robust for the secondary and sensitivity analyzes. To give our readers an idea of ​​the magnitudes we are talking about, a μg (microgram) is one millionth of a gram. That is, a small increase in long-term exposure to PM2.5 leads to a large increase in the COVID-19 mortality rate.

Despite the inherent limitations of the ecological study design, the results underscore the importance of continuing to enforce existing air pollution regulations to protect human health during and after the COVID-19 crisis. The data and code for this study are publicly available, so analyzes can be routinely updated.

Despite the inherent limitations of the ecological study design, the results underscore the importance of continuing to enforce existing air pollution regulations to protect human health during and after the COVID-19 crisis. The data and code for this study are publicly available, so analyzes can be routinely updated.
And not only that, but it also makes us think that the decrease in the lethality observed in early May, is not due to a supposed and hypothetical weakening of the virus, denied by the main virologists, or the decrease in the insignificant viral load of the new infected, but by the brutal drop in pollution in the main cities and manufacturing centers, the return of which can cause a further increase in serious cases, which will require further budgets and respirators.

Although longer-term studies will be required to characterize this increased mortality from COVID-19 caused by air pollution, and to further refine the potential variability factors in the analysis, it seems clear that we must drastically reduce and in the least possible time our emissions of suspended particles, not only to try to reverse the most harmful effects of anthropogenic global warming that we suffer, but also to immediately improve health worldwide and mitigate the effects of the current coronavirus pandemic, and those of other pandemics that could undoubtedly plague us in the future.

Do we need more notices?