Wuhan, Northern Italy, Tehran, Madrid & mldr ;: What do the first places where the covid-19 ravaged have in common? One possible answer is the contamination.
It is not yet fully known if it is true that pollution plays a role in the transmission of the disease, but indications have been accumulating that it could be so. The World Meteorological Organization concluded in August that “population exposure to air pollution, in the form of particulate matter, affects the severity of symptoms of covid-19.”
15% of deaths by covid-19 could be attributed to pollution
The last hint comes from a study published in the journal ‘Cardiovascular Research’. Its authors estimate that a 15% of deaths Coronavirus totals could be attributed to long-term exposure to contamination – specifically to PM2.5 particles (particles with a diameter equal to or less than 2.5 microns, produced for example by cars).
The study generalizes to the whole world results found in previous studies in the United States, China and Italy. “The relationships found in these three studies are strikingly similar,” he observes. Jos Lelieveld, co-author and director of the Max Planck Institute for Chemistry.
The strongest indication
The job of the United States, carried out by researchers from Harvard University, is considered the most exhaustive on the subject. These scientists have been analyzing data from 3,000 US counties. The study has confirmed that sites with historically higher levels of PM2.5 have higher levels of mortality from covid-19.
“Population exposure to air pollution […] affects the severity of covid-19 symptoms “
Conclusions of the symposium on environmental factors of the pandemic
The conclusion might seem like a truism. “Suffering contamination for a long period of time obviously increases the risk of respiratory diseases. As COVID-19 is a respiratory disease, once it appears, it will find itself with more vulnerable lungs and it will be more severe,” he reasons. Maria Neira, Director of the Department of Public Health and Environment of the World Health Organization (WHO).
However, reaching definitive conclusions is not easy. The Harvard team had to discount the effects of up to 20 other factors that could interfere with the outcome: from the age of the population in each county, to its density, the prevalence of obesity and smoking, income, and the availability of hospital beds.
That is not enough to reach a categorical conclusion either. To do this, studies are needed that follow a large number of individual patients during years. The Harvard study uses aggregated data at the geographic area level.
“Reducing pollution would have a lesser effect than social prevention measures”
Investigator of the Italian National Investment Center
“In any case, reducing pollution would have a less effect than social measures prevention: distance, mask, ventilation, hand washing, etc. ” Gemine Vivone, author of a study who has found a correlation between particulate matter and admissions to intensive care for covid-19. “As weapons of immediate prevention, one should not deviate from these measures. However, reducing pollution could help,” Neira observes.
Do pollution peaks influence?
Among the pending issues is the role of other pollutants other than particulate, specifically NO2. However, the burning question is the effect of acute pollution episodes.
In the early phases of the pandemic in Italy, there were much more peaks of pollution in the north than in the south, something that went hand in hand with the distribution of the epidemic in that country, according to showed the team of Prisco Piscitelli, deputy director of the Italian Society of Environmental Medicine. Piscitelli, too found RNA from the coronavirus stuck in airborne particles in the city of Bergamo, one of the worst hit.
“Reducing pollution reduces an important risk factor: don’t wait for more evidence”
Director of the WHO Department of Public Health and Environment
“There are short term benefits in reducing pollution: during confinement, hospitalizations for acute respiratory problems were reduced “, observes Neira. Jordi Sunyer, an air quality expert from the Barcelona Global Health Institute (ISGlobal) disagrees. “The acute effect of the contamination is not very important. Two or three months of confinement are not enough to counteract the long-term effect,” he concludes.
“Although we are far from establishing cause and effect relationships, there is no doubt that reducing pollution would be very beneficial in reducing an important risk factor: it is not a question of waiting for more evidence”, concludes Neira.