Air pollution is a public health problem that claims around seven million lives per year worldwide, according to data from the World Health Organization. In Spain, 3% of annual mortality (period 2000-2009) was attributable to poor air quality.
In addition, mortality is just the tip of the iceberg, as explained by Julio Díaz Jiménez, researcher at the Carlos III Health Institute in an information conference on contamination and health organized by the Society of Pulmonology and Thoracic Surgery (SEPAR). The effects of pollution are also felt in the increase in hospital admissions, chronic diseases, allergies and, ultimately, in a considerable decrease in the quality of life of people living in polluted environments, which in our country means in around 35% of the population. In addition, many of the Spanish cities systematically fail to comply with European regulations in this regard.
The respiratory system is one of the most affected by exposure to pollution: “a person who does not smoke but lives in continuous contact with high levels of pollution is exposed to the equivalent of smoking between 5 and 10 cigarettes a day, ” he highlighted. Carlos A. Jiménez-Ruiz, president of SEPAR.
“It is estimated that in Spain almost 10,000 deaths per year are attributable to air pollution,” explained Díaz. “If we compare it with the mortality associated with traffic accidents , which for example in 2015 was 1,126 people, it is a lot. Very effective campaigns have been and are being carried out to raise awareness about road safety and reduce accidents, it would be necessary to do the same with pollution ”, reflects the expert.
What are the most harmful pollutants?
When we refer to pollution and its effects, it is convenient to differentiate between some particles and others, since not all of them behave in the same way or have the same effects. Many times we hear about PM10, PM2.5, PM1 , etc., which are terms that refer to suspended particles classified by their size. The coarsest particles, PM10, have a diameter between 2.5 and 10 microns. Being larger, they are less harmful, since they are retained in the upper respiratory tract. The smaller its diameter, the more damaging the particles are, as they can cross the pulmonary alveoli and end up reaching the bloodstream. Diesel engines emit this type of small diameter particles in a higher proportion than gasoline engines, hence the traffic restrictions in cities are often applied in the first place on this type of vehicle.
Regarding the different pollutants, the most dangerous for health are nitrogen, ozone, particulate matter, sulfur dioxide, carbon monoxide and lead. Nitrogen dioxide has been responsible for 6,085 preventable deaths each year in Spain and, among its serious health risks, the worsening of asthma and respiratory failure stand out. As for tropospheric ozone, this is a secondary pollutant that is formed by a reaction of sunlight with emissions from vehicles and industries, and its excess also generates respiratory problems such as asthma and can cause lung diseases.
There is more ozone in the periphery of cities
The behavior of tropospheric ozone is peculiar, since it is destroyed in contact with nitrogen monoxide (see figure), so that in highly polluted environments and with more presence of this compound, ozone concentrations are low. It is in the periphery where the highest levels accumulate, and thus there are striking situations such as that, for example, the highest peaks of this pollutant in Madrid are registered in some towns in the mountains or in parks.
In addition, there is another pollutant that often goes unnoticed: noise, but which also causes different effects on health and is associated, for example, with an increase in mortality from cardiovascular causes.
Air pollution wreaks havoc on human health, but the good news is that we can avoid it. Policies aimed at restricting traffic during high pollution episodes are effective and manage to reduce the levels of harmful compounds in urban areas. “There is no doubt that improving air quality increases life expectancy , reduces hospital admissions, improves lung function and reduces mortality,” said Isabel Urrutia Landa, coordinator of the Occupational Respiratory Diseases Area and Environmental of SEPAR.
