The intense heat wave that the center, east and south of the Iberian Peninsula has suffered in the last week has caused the levels of ozone and particles in the air to have skyrocketed, due to the combined effect of polluting emissions from motorized traffic and maritime transport, high temperatures and the arrival of dust from North Africa.
Between August 10 and 17, in Andalusia, Castilla-La Mancha, Catalonia, the Valencian Community and the Community of Madrid, there have been twenty-five exceedances of the information threshold for the population established by the ozone regulations, which is set at 180 micrograms of ozone per cubic meter of air, as an hourly average.
The maximum contamination was registered at the Valdemoro station (Madrid) on Monday, August 16, where an ozone level of 203 micrograms per cubic meter was reached. Altogether, in the Community of Madrid and Castilla La-Mancha, at the end of the heat wave, seventeen exceedances of the information threshold were detected that day, distributed among the stations in the southern urban area of Madrid (Aranjuez, Getafe, Leganés and Valdemoro) and north of Toledo (Illescas, Talavera de la Reina and Toledo), with intense motorized traffic.
On the other hand, in Catalonia, there have been five exceedances of the information threshold, between Friday 13 and Saturday 14 August, at the Plana de Vic stations (Manlleu, Tona and Vic) and at Montseny, to the north from the metropolitan area of Barcelona. The exceedances of the Valencian Community and Andalusia were recorded on Friday the 13th in Sagunto (Valencia), on Saturday the 14th in Alcoy (Alicante) and on Sunday the 15th in El Arenosillo (Huelva).
The forecast of exceeding the information threshold obliges the regional authorities to warn the people most sensitive to air pollution, such as boys and girls, the elderly, pregnant women or people with respiratory or cardiovascular problems, to protect themselves by avoiding in the central hours of the day and in the late afternoon any physical effort and outdoor exercises. They must also report on the forecast of evolution of the contamination, the affected areas and the duration of the episode.
However, the Generalitat de Catalunya notified of the exceedances one day late “due to technical problems”, and the Generalitat Valenciana did not even report on them. The Community of Madrid, the Junta de Castilla-La Mancha and the Junta de Andalucía limited themselves to broadcasting routine notices once the exceedances occurred, which are insufficient to protect the health of the most affected population.
Apart from exceeding the information threshold, in half of the 500 stations that measure ozone in Spain, spread over Andalusia, Aragon, Navarra, La Rioja, both Castillas, Extremadura, Catalonia, Valencia, Madrid and Murcia, it has been exceeded also the objective established by the regulations to protect health, in some cases for several consecutive days, in the face of the passivity of the regional and local administrations, which still do not draw up the mandatory plans to improve air quality with respect to ozone.
The ozone pollution episode has coincided in time with the rise in levels of particles below 10 microns (PM10), due to the entry of the air mass from North Africa, which in addition to the temperatures has triggered the levels of airborne dust throughout the center and south of the Iberian Peninsula, and also in the Canary Islands.
Thus, in the cities of Albacete, Alicante, Almería, Ávila, Barcelona, Cádiz, Castellón, Ciudad Real, Córdoba, Cuenca, Girona, Granada, Guadalajara, Huelva, Jaén, Las Palmas, Lleida, Madrid, Malaga, Murcia, Palma, Puertollano, Santa Cruz de Tenerife, Segovia, Seville, Soria, Tarragona, Toledo, Valencia, Valladolid or Zaragoza the daily limit value for PM particles has been exceeded10, legally established at 50 micrograms per cubic meter.
Highest levels of PM particles10 they have been reached in the last week in Alicante and Guadalajara, tripling the daily limit value. However, the most serious situation has occurred in cities that have accumulated more than three consecutive days above the legal limit, highlighting Albacete, Granada and Seville, with seven consecutive days of non-compliance. It so happens that the high concentrations of particles could have alleviated ozone levels, by sifting the solar radiation that activates its formation.
Only the Cantabrian coast has been spared the episode of pollution by ozone and particles, which highlights the growing importance of climate change in the worsening of situations of high air pollution in summer, due to the progressively greater frequency, duration and virulence of summer heat waves. The dust from North Africa also incorporates toxic substances emitted by the Algerian and Moroccan industry.
The Carlos III Health Institute has estimated 3,500 annual deaths caused by short-term exposure to particles and ozone in thirty Spanish provinces where a significant association between air pollution and mortality has been found.