another summer short – with the highest temperatures limited to the months of July and August – has reduced ground-level ozone pollution in almost all of Spain. Except in the Community of Madrid, where the capital has in fact recorded the worst health data since records began, according to the compilation carried out by Ecologistas en Acción.
This Monday, the Council of the European Union definitively approved the revision of the Air Quality Directive. The standard reduces by almost half the maximum limits for many toxic substances we breathe, such as nitrogen dioxide or microparticles (PM). There is a two-year deadline to transfer the regulations into Spanish legislation and these new limits must be respected by January 1, 2030. The legal thresholds for tropospheric ozone concentration have also been revised in order to reduce the authorized days during which the limit is outdated. maximum concentration.
This ozone bad (O3) is generated when the sun’s rays hit other gases released into the atmosphere, such as nitrogen dioxide from exhaust pipes. This is why peaks occur during the summer months and can be measured far from urban centers. “It’s an ozone problem, because at this time of year many people are in places where they would never think of breathing contaminated air, and that is the case,” explains Juan Bárcena , responsible for air quality at Ecologistas. And this is also why a “hot and humid” summer, as AEMET described 2024, has improved the situation in many places: “During 2024, levels fell due to the longer duration short of high summer temperatures and solar radiation. analysis of environmental organization.
This situation does not fail to confirm the relationship between tropospheric ozone, a photochemical pollutant, and climate change generated by human activities. This toxin generally shows an increasing trend in Mediterranean Europe, where summers are getting longer, with higher temperatures and strong heat peaks in the form of waves. In other words, solar radiation hits longer and with more force, which multiplies the O3. In the event of a slightly gentler development, the generation of pollutants is also attenuated.
However, “today there is no territory free from atmospheric pollution,” says Ecologistas en Acción. They refer to the fact that ground-level ozone (an oxidant that primarily irritates the respiratory tract) invades whole map of Spain. The European Environment Agency attributes more than 2,000 premature deaths in the country to this compound each year.
If we compare it to the legal limit still in force, six million people live in areas whose O3 concentration is higher than this threshold, already considered obsolete because it is too high. The areas where these particularly harmful concentrations have been measured are the Community of Madrid, the agglomeration of Guadalajara, the Tiétar valley and the Alberche d’Avila, the Plana de Vic and the Catalan Prepirineu and Villanueva del Arzobispo (Jaén). If we take into account the new – more demanding – maximum already approved by the European Union and which will be activated in 2030, almost nine million people are in this situation. One in six Spanish citizens.
But, according to World Health Organization criteria, 46 million people, or 96% of the population, were exposed to harmful concentrations of ground-level ozone this year.
The coordinator of Ecologists in Action, Carmen Duce, insists that “we cannot afford to wait almost 15 years between the approval of air quality limits in the European Union and their compliance , as was the case with previous regulations. In addition, there are now only six years left to respect the lower limits (which are also not those of the WHO).”
In the capital, 11 of the 13 stations that measure ozone and the average of the entire municipal network exceeded the value set by regulations, the maximum limit, for more than 25 days.
The Community of Madrid appears to be the epicenter of tropospheric ozone pollution in Spain: “All measuring stations have recorded numerous exceedances of the maximum daily value set by legislation”, confirm ecologists after examining the records surveillance networks of the regional government and the city of Madrid. Advice.
Levels in the community are higher than other years “due to the high temperatures and hours of solar radiation achieved during the summer.” This confirms the trend that makes this region a leader for this pollutant (even if the total volume of, for example, nitrogen dioxide has decreased).
At the head of the problem in 2024 is the city of Madrid. In the capital, 11 of the 13 stations that measure ozone and the average of the entire municipal network exceeded the value set by regulations, the maximum limit, for more than 25 days. The 35 exceedances of the legal maximum daily limit in 2024 are 28% higher than the average for the period 2012-2019. The maximum since 2010. The black spot is located in Casa de Campo (it has exceeded the limit 70 times), which confirms the risk for users of the city’s large park.
Besides the main city of the Community, the worst data were concentrated in the Henares corridor, the Sierra Norte and the Tajuña basin.
The organization’s analysis indicates that primary pollution generated by traffic in the Madrid metropolitan area and Barajas airport “spreads throughout the territory”, which causes the formation of tropospheric ozone when it is exposed to the sun “in areas very far from the capital”, an example of what the negative cycle of this pollutant looks like.
However, the National Ozone Plan has not yet been developed, the preparation of which by the executive has dragged on since 2015. “Unacceptable”, conclude the environmentalists.
