Qualité de l’air à Rome

What is the air quality index of Rome?

Rome is the capital city and a special comune of Italy (named Comune di Roma Capitale), as well as the capital of the Lazio region. In 2019 it had a population of around 4.3 million people.

Rome is located in the central area of the Italian Peninsula on the west coast. It straddles the banks of the River Tiber. Vatican City which is officially the smallest country in the world is an independent country within the city boundaries of Rome and is the only example of a country within a city.

In January 2021, Rome was experiencing a period of “Moderate” quality air with a US AQI figure of 85. The recorded level of the PM2.5 pollutant was 28.1 µg/m³. These figures are based on the suggested levels by the World Health Organisation (WHO).

With levels such as these, the advice is to close doors and windows to prevent the ingress of dirty air and those of a sensitive disposition should avoid outdoor exercise until the air quality improves.

What is the main source of air pollution in Rome?

People living in an urban area are exposed to a mixture of environmental pollutants. The main sources of pollution are vehicular traffic and domestic heating (especially when diesel or biomass are used). Natural particle emissions come from the sea, soil and plants. Man-made emissions are largely the result of burning fossil fuels such as coal, oil, gasoline or diesel.

The main air pollutants are carbon monoxide (CO), nitrogen dioxide (NO₂), ground-level ozone (O₃), particulate matter (PM2.5 and PM10), sulphur dioxide (SO₂), hydrocarbons and lead (Pb). Each comes from different sources, has its own chemical behaviour and causes different health effects, which makes the task of understanding and controlling air pollution as a whole very complex.

Primarily, it is the atmospheric conditions that determine what happens once the pollutant is released into the air. In windy or rainy conditions the pollution concentrations remain low, the pollutant can be swept away, or removed from the rain by deposition.

What is the pollution level in Rome?

In 2019. The average annual figure was 12.9 µg/m³ which classed the air quality as “Moderate”. For the months of May and November, Rome achieved the WHO target figure of 10 µg/m³ or less. In April, July, August and September the level was “Good” with readings between 10 and 12 µg/m³. For the remaining 6 months, the quality was “Moderate” with readings between 12.1 and 35.4 µg/m³.

The air quality monitoring stations in Rome detected a critical situation due to the exceeding of the permitted levels of PM10 by law, in many areas of the city. In order to contain atmospheric pollution, the local authorities have ordered the limitation to circulation for the most polluting vehicles for the 3^rd February 2020.

The banned vehicles included pre- “EURO 1" and "EURO 1" mopeds and motorcycles, two, three and four-wheelers, equipped with 2 or 4-stroke engines. “EURO 2” petrol-powered vehicles were also to be included.

Is air pollution in Rome getting better or worse?

Towards the end of December 2020, Rome was experiencing a period of stagnant air. Without wind or rain, the pollution hangs in the air. The local authorities made the request to the people of Rome, not to use their cars and motorbikes, but to use public transport instead. They were also asked to limit the start-up times for their heating systems and lower the overall room temperature by a few degrees.

The main sources of pollution are from vehicular traffic and domestic heating. A possible solution to the phenomenon could come from the promotion of less polluting energies such as LPG or LNG, which produce much lower carbon dioxide emissions than fossil fuel sources. According to a survey conducted in 2019 on the domestic consumption of wood biomass in Lazio, the families who use wood biomass for heating exclusively are still 64 per cent, with the use of fireplaces and pellet stoves. In Lazio 73 per cent of the car fleet is fuelled by petrol (between Euro 0-4 standards), explained the promoters of the conference. If 50 per cent of the cars were converted to LPG, an emission reduction of 115 tons per year of nitrogen oxides and 106,800 tons of carbon dioxide per year would be obtained.

If heavy vehicles such as trucks, buses and lorries were powered by LNG instead of diesel, they could reduce the emissions of various pollutants, minus 96 per cent of particulate matter, 32 per cent nitrogen oxides and 15 per cent carbon dioxide. The latter could reach a 95 per cent reduction if LNG were produced from the liquefaction of biomethane. Even ship transport is not without fault when it comes to pollution: they are normally powered by BTZ heavy fuel oil. If LNG were used instead of BTZ heavy fuel oil, it could see a reduction in the emissions of various pollutants: minus 100 per cent particulate matter, 90 per cent nitrogen oxides and 25 per cent carbon dioxide. Port authorities should encourage vessels to switch to this cleaner fuel by offerings incentives such as a reduction in port fees or similar.

What can be done to improve the air quality in Rome?

In December 2019, the local authorities launched the "NO₂, no thanks" which was to be a survey to ascertain the levels of nitrogen dioxide throughout the city. NO₂, emitted mainly by diesel engines, is very harmful to health, especially that of children. It has a large impact on the foetus and the development of the cognitive system of the growing child. For the 2020 survey, it was decided to place part of the instrumentation at 80 centimetres from the ground, at the height of the exhaust pipe and the average height of a young child.

Each participant was invited to register their interest on a website. The collection of the kit took place in January ready for use in February. Then the samplers were placed in the point chosen by each participant and remained exposed for four weeks, detecting nitrogen dioxide by absorption.

In March the kits were collected and the results analysed. The results were published in May and made available to anyone who accessed the website.