Air pollution in Spain fell in 2020 to its lowest level in ten years due to restrictions against the pandemic

"The essential factor to explain the improvement in air quality during 2020 is the general reduction in mobility and economic activity derived from the two states of alarm declared to combat COVID-19," the organization analyzes. They also point to the cessation of activity of thermal power plants. Last year's records show a "notable reduction" in concentrations of nitrogen dioxide (NO2), tropospheric ozone (O3) and sulfur dioxide (SO2). "It is more nuanced for microparticles", which have been revealed as a very harmful toxic to human health, the review adds.

This analysis is the confirmation of the trend that could be observed throughout 2020: fewer cars (together with fewer economic activities) make the air cleaner. The fall due to the decrease in traffic with diesel and gasoline vehicles and industrial activities has meant that, for example, the metropolitan areas of Barcelona, ​​south of Madrid, Murcia and Bilbao have not exceeded the legal limits of NO2. In fact, the city of Madrid is the only urban agglomeration in Spain that exceeded the mandatory threshold. Thus, the population exposed to concentrations above that established by the regulations for the protection of health was reduced by half: from more than 6 million to a little more than three - the inhabitants of the capital of Spain.

Regarding tropospheric ozone –which is produced when the sun's radiation affects previously emitted compounds such as NO2 itself–, as there are fewer precursor products in the atmosphere, there has been a significant drop in episodes of exceeding the limits established by law: decreased by 55% compared to the average between 2012-2019. However, 4.2 million people were exposed last year to excessively high levels of this powerful oxidant with proven harmful effects on the respiratory system. The areas with the worst records, which are located in rural areas, were distributed between the Community of Madrid, Cáceres, the south of Castilla y León, the interior of Catalonia and the Valencian Community, the agglomeration of Córdoba and, to the north of this, the industrial zone of Puente Nuevo.

This gas also damages vegetation. In this case, the area affected by a legal excess of O3 reached 210,000 km2 (41% of the Spanish territory). Although it is a large area, it follows the 2020 trend and represents 43,000 km2 less than in 2019. The worst data are, above all, in the center and south of the Iberian Peninsula.

For the finest particles, PM 2.5, Ecologistas en Acción's analysis reflects that there were no exceedances of legal limits. The organization estimates that 17.8 million people breathed air with a PM 2.5 concentration above that recommended by the World Health Organization (which is a stricter level, but not mandatory). It is a sharp drop of 8.8 million people from the previous year. However, the work warns that "the measurement and evaluation of PM2.5 particles is clearly insufficient in most of the autonomous measurement networks. There are still few stations that measure this pollutant." They suggest that a good portion of the problem may be being hidden.