Italian National Agency for New Technologies, Energy and Sustainable Economic Development
Environment: International study on the benefits of anti-Covid measures for pollution and health in Europe
Some anti-Covid measures adopted at the beginning of the pandemic – such as the lockdown and traffic restrictions – led to a dramatic decline in air pollution, with consequent health benefits as well. An international study on air quality trends in 47 European cities—including Rome, Milan, Paris, London and Barcelona—highlights this. Carried out by numerous research institutions, including ENEA, the study was published in Nature [1].
The investigation reveals, in particular, that the sharp drop in air pollution levels during the monitored period (February–July 2020) was mainly due to limitations on daily city travel and the obligation to stay at home, while the restrictions on movement between regions and international travel had less of an impact. The pollutant most sharply reduced was nitrogen dioxide (NO2), which fell by over 50% in seven cities (Milan, Turin, Rome, Madrid, Lisbon, Lyon and Paris).
“The decline was mainly due to the ban on road transport and traffic, which is the main source of emissions of this pollutant. Concentrations of nitrogen dioxide began to fall as early as the first half of March 2020, when the governments imposed the first restrictions; the differences between cities can only be related to the different implementation times of the bans and variation in the severity of the measures”, explains Mario Adani, an ENEA researcher in the Air Pollution Laboratory and co-author of the study.
Milan, for example, was the first city to record a drop in NO2 pollution, with concentrations minimised around mid-March. “Milan and the Po Valley have some of the highest levels of pollution in Europe. Thus the fall in concentrations due to the lockdown was considerable, as was the reduction in premature mortality”, Adani adds.
London instead saw a perceptible drop only in the second half of March. Largely reflecting less stringent policies, Stockholm’s drop was limited. Following the sharp drops of March and April, the variations in NO2 and particulate matter (PM) declined in all the cities, although levels remained below the business-as-usual scenario (that is, in the absence of any intervention).
Compared to the sharp plunge in nitrogen dioxide pollution, the study revealed a more modest reduction in PM10 and PM2.5 levels, while in some cities, particulates even increased slightly. The causes are mainly to be found in the complexity of particulate matter, which also comprises natural and secondary components produced in the atmosphere that do not decrease proportionally with NO2[2].
Moreover, the greater amount of time spent at home led to the increased use of heating, and in particular of wood-powered devices.
The study also quantified the number of premature deaths avoided following the reduction in pollution caused by the measures taken by EU governments against the pandemic. From February to July 2020, the total number of avoided deaths 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 saw the largest number of deaths avoided in relation to nitrogen dioxide (NO2) and particulates. For Italy, the study quantified the deaths avoided in Milan, Naples, Rome and Turin for each of the pollutants analysed. For example, in Rome 18 deaths were avoided from NO2, 6 from O3, 7 from PM10 and 5 from PM2.5.
“The government’s response to halt the spread of the pandemic offered an unprecedented case study to quantitatively assess a series of drastic and short-term reductions in anthropogenic emissions. It intervened in various sectors, from road transport to energy production, from manufacturing to commercial and public services and the air and maritime sectors. This is an important lesson for Italian administrations regarding the management of critical episodes of air pollution, in particular from particulates, which remained stable—even given strong limitations to emissions—in the days following the pollution peaks”, concludes Antonio Piersanti, director of the Air Pollution Laboratory at ENEA.
To simulate air pollution concentrations in the sample cities, a set of six chemical and air pollutant transport models were deployed, including ENEA’s ‘MINNI’ model. The models provide daily forecasts of air quality for the European Union under the ‘Copernicus Atmosphere Monitoring Service’ (CAMS) program, one of six EU ‘Copernicus’ services that provide information about air pollution, health, greenhouse gases and climate based on data acquired and integrated in situ, from satellites, and through modelling.
For more information:
Antonio Piersanti, ENEA - Air Pollution Laboratory,
Mario Adani, ENEA - Air Pollution Laboratory,
The study published in Nature: https://www.nature.com/articles/s41598-021-04277-6
For more information on air quality forecasts:
- At the European level: https://regional.atmosphere.copernicus.eu/
- At the national level: http://airqualitymodels.enea.it
Note
[1] In particular, ENEA participated with the MINNI air pollution assessment system (National Integrated Model to Support International Negotiation on Air Pollution Issues http://airqualitymodels.enea.it/). This consists of an atmospheric modelling system (AMS), which simulates chemical-physical processes in the atmosphere and provides the concentrations of the main primary and secondary pollutants across Italy at one-hour windows, and by GAINS-Italia, an analysis tool that evaluates the cost and impact of reductions in concentrations.
[2] For example, ammonium nitrate; ammonia emissions from fertilisers and farms, which did not change during the lockdown, contribute to this pollutant.