Reports from those who today look at the sky, or simply leave their homes, in the areas most affected by the wildfires, indicate clouds of smoke and black, orange, or yellow veils covering the air. The high level of smoke in the air, caused by the fires that have been raging since Sunday and affecting especially the North and Central regions of the country, has even led the National Emergency and Civil Protection Authority to recommend the adoption of special protective measures and to avoid, as much as possible, exposure to the air. On the topic, Professor António Jorge Ferreira from the Faculty of Medicine at the University of Coimbra explains to PÚBLICO that the issue at hand concerns the harmful effects on human health caused by suspended particles.
“We have indeed observed a significant deterioration in air quality conditions, especially due to exposure to particulate matter, the so-called PM2.5 and PM10,” the specialist notes. But what are these particles and why should we protect ourselves?
Particles can have human origins, such as industrial, commercial, or residential combustion, among others, or have a natural source: volcanic eruptions, wildfires, wind action on soil and water surfaces. We have heard about them, for example, when clouds of dust carried by air masses from North Africa affect Portugal.
“In Coimbra, for instance, the levels are much higher than usual. We are reaching very high values, especially in recent hours and particularly concerning particulate matter,” António Jorge Ferreira exemplifies.
In practice, we are talking about particles that exist in the atmosphere and are of “very tiny dimensions, that is, PM10 are particulate matter smaller than ten micrometers in diameter” and PM2.5 are even smaller, less than 2.5 micrometers. “These are particles that easily enter our respiratory and cardiovascular systems,” interfering with the respiratory process and posing serious health risks.
As a consequence of excessive exposure to these materials, there may be “health damage, which can be more acute or more chronic,” the specialist further indicates. These can include not only respiratory problems but also issues related to cardiovascular and cerebrovascular health.
“In the case of PM10, for example, today [Tuesday], several detectors nationwide in these more complex areas, particularly in the Center region, are monitoring values that are up to ten times higher” than those recommended by the World Health Organization. In Portugal, as confirmed by the Portuguese Environment Agency (APA) — which monitors air quality on a scale ranging from “poor” to “very good” —, “the concentration of particles in ambient air is subject to regulation and control.”
Poor air quality in Gaia and Aveiro
PÚBLICO consulted the APA website dedicated to air quality on Tuesday afternoon and, for example, the following monitoring stations were marked as “poor”: Sobreiras-Lordelo do Ouro, Avintes (both in Vila Nova de Gaia), Mindelo – Vila do Conde, Cónego Dr. Manuel Faria-Azurém (Guimarães), Estarreja, Aveiro, among others. On the other hand, stations located, for example, in Porto or Matosinhos did not show any values on this index on the site.
Given the consequences of exposure to these particles, which, once released or formed in the atmosphere, are carried by the wind over long distances, the recommendation is indeed to minimize exposure to the air in affected areas. On the other hand, “the advice also aims for citizens to stay informed” through channels from organizations such as the Directorate-General of Health, the Order of Physicians, or the Portuguese Society of Epidemiology.
“The populations most vulnerable are often the first to seek health services, precisely due to exacerbation of their pre-existing diseases. And here most situations involve, for example, exacerbation of asthma or chronic obstructive pulmonary disease. We also have many cases of acute bronchitis and decompensation of other pre-existing diseases, namely cardiovascular disease or heart failure,” reflects António Jorge Ferreira, while warning: “The air quality on these days remains deteriorated, generally for periods that are not so small.”
Regarding the expulsion of these particles from the body, there is no definitive answer. However, it is known that “in the weeks following these phenomena, there are usually increases in incidence and prevalence of some types of diseases, particularly respiratory and cardiovascular”. “And we also know that there is, globally, increased mortality associated with excessive exposure to these particles,” concludes the specialist.