(Finance) – Some anti-Covid measures adopted at the beginning of the pandemic – such as lockdowns and restrictions on circulation – have led to a drastic decrease in air pollution with consequent benefits also for health. This is what one highlights international study on air quality trends in 47 European cities, including Rome, Milan, Paris, London and Barcelona, published on Nature and made by numerous research institutions, including Enea.
From the investigation – explains Enea in a note – it emerges, in particular, that the sharp drop in atmospheric pollution levels in the monitored period (February-July 2020) it is mainly due to the limitation of daily movements in the city and the obligation to stay in homes, while restrictions on circulation between regions and international travel have had less impact. The pollutant that has undergone the greatest reduction is the nitrogen dioxide (NO2), more than halved in seven cities (Milan, Turin, Rome, Madrid, Lisbon, Lyon and Paris).
“The decrease is mainly due to the prohibition of circulation and road transport, which is the main source of emissions of this pollutant. The concentrations of nitrogen dioxide – he explains Mario Adani, Enea researcher of the Atmospheric Pollution Laboratory and co-author of the study – they started to plummet since the first half of March 2020, when governments imposed the first restrictions; the differences between the cities can only be related to the different timing of implementation of the blocking policies and to the variations in the severity of the measures “. Milan, for example, it was the first to record a decline in NO2 pollution, with concentrations reduced to a minimum around mid-March. “Milan and the Po Valley have some of the highest pollution levels in Europe and therefore the drop in concentrations due to the lockdown – adds Adani – was strong as well as the reduction in premature mortality”.
London, instead, it had a significant decrease only in the second half of March, while Stockholm it fell less, mainly due to less stringent policies. But, after the sharp decline in March and April, all cities have registered an attenuation in the variations of NO2 and particulate matter (PM), while maintaining levels lower than in the business as usual scenario, i.e. in the absence of any intervention.
Compared to the sharp decline in nitrogen dioxide pollution, the study highlights one more modest reduction in PM10 levels and PM2.5 while in some cities, fine particles have even registered a slight increase. The causes are mainly to be found in the complexity of the composition of the particulate, which also includes natural and secondary components produced in the atmosphere that do not decrease in proportion to the decrease in the NO2 precursor. Furthermore, the greater stay of people at home has led to a greater use of heating, in particular of wood-fired devices.
The study also quantified the number of premature deaths avoided as a result of the reduction in pollution as a result of the measures adopted by EU governments against the pandemic. From February to July 2020, the total number of deaths averted was 486 for nitrogen dioxide (NO2), 37 for ozone (O3), 175 for PM2.5 and 134 for PM10; in particular, Milan, Paris, London and Barcelona were among the first cities with the highest number of deaths avoided by nitrogen dioxide (NO2) and fine particles. And for Italy, the study quantified the deaths averted in Milan, Naples, Rome and Turin, for each of the pollutants analyzed. For example, 18 deaths from NO2, 6 from O3, 7 from PM10 and 5 from PM2.5 were avoided in Rome.
“The response of governments to curb the spread of the pandemic – he says Antonio Piersanti, head of the Atmospheric Pollution Laboratory of Enea – offered an unprecedented case study to quantitatively evaluate a series of drastic and short-term reduction interventions in anthropogenic emissions, intervening in various sectors, from road transport to energy production, from manufacturing industry to commercial services and public up to the aviation and maritime sectors. This is an important indication for the Italian administrations regarding the management of critical episodes of atmospheric pollution, in particular from fine dust, which remain stable, even with severe limitations of emissions, in the days following the pollution peaks “.
To simulate the concentrations of air pollution in the sample cities, a set of six models of chemistry and transport of pollutants in the atmosphere was fielded, including MINNI of Aeneas, who carry out daily air quality predictions for the European Union within the “Copernicus Atmosphere Monitoring Service” (CAMS) program, one of the six services of the EU Copernicus program that provide information on air pollution, health, greenhouse gases and climate based on data acquired and integrated by satellites, in situ and modeling.