Descrizione 1
Antonella Bernetti, Antonio Caputo, Francesca Palomba
The indicator allows for the assessment of emissions of major air pollutants produced by the transport sector. In Italy, harmful emissions from road transport have significantly decreased in recent years thanks to the introduction of catalytic converters, particulate filters, and other vehicle-installed technologies. From 1990 to 2022, road emissions of non-methane volatile organic compounds (NMVOCs) decreased by 88.2%, nitrogen oxides (NOx) emissions by 74.8%, and fine particulate matter (PM) emissions by 75.0%. Sulfur oxides (SOx) emissions, now nearly absent from road transport, remain significant in maritime transport. The 2020 estimates reflect the effects of the pandemic, while 2021 and 2022 show a gradual recovery. Pollutant emissions into the atmosphere are monitored at the national level to verify compliance with reduction commitments imposed by European legislation, aiming to achieve air quality levels that do not cause significant negative impacts or risks to human health and the environment.
This indicator covers emissions of key air pollutants, namely nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs), particulate matter (PM), lead (Pb), benzene (C6H6), and sulfur oxides (SOx). Nitrogen oxides contribute to acid rain, eutrophication, tropospheric ozone formation, and indirectly to global warming and ozone layer depletion. Particulate matter is currently the pollutant with the greatest impact on human health, especially the fine fraction (PM2.5), which can penetrate deeply into the lungs. PM is harmful both as an irritant and as a carrier of trace pollutants potentially mutagenic or harmful to the lungs and bloodstream. Secondary particulate matter forms in the atmosphere, contributed to by emissions of NOx, SOx, ammonia, NMVOCs, and ozone, which results from the reaction between NOx and NMVOCs in the presence of heat and sunlight, primarily during summer months. Benzene is a carcinogenic compound present in trace amounts in gasoline and vehicle exhaust.
To evaluate emissions of the main atmospheric pollutants produced by the transport sector to verify achievement of European targets for national total emission reductions and assess the sector's contribution to environmental pressure in air quality-critical areas.
Under the UNECE Convention on Long-Range Transboundary Air Pollution (CLRTAP), Italy is required to update and report annually national air pollutant emission inventory. EU Directive 2016/2284 on national emission ceilings defines reduction commitments for total emissions of SO2, NOx, NMVOCs, NH3, and PM2.5, requiring road transport emissions to be calculated and reported based on fuel sales in Member States, which may alternatively use fuel consumption or vehicle kilometers traveled. Road vehicle emissions are regulated at the EU level separately for light-duty vehicles (passenger cars and light commercial vehicles) and heavy-duty vehicles (trucks and buses). Regulation (EC) No 715/2007 covers type approval of motor vehicles concerning emissions from passenger cars and light commercial vehicles (Euro 5 and Euro 6), while Regulation (EC) No 595/2009 covers type approval for heavy-duty vehicles (Euro VI). Euro 5 and 6 standards for light-duty vehicles became mandatory from January 2011 and September 2015 respectively, notably Euro 6 significantly reduces NOx emissions from diesel cars. Since September 2017, the standardized driving cycle for type approval tests has been the WLTP (Worldwide Harmonized Light Vehicles Test Procedure), complemented by the RDE (Real Driving Emissions) test. Between 2018 and 2021, Euro 6 regulations have undergone multiple revisions introducing increasingly stringent testing protocols with WLTP and RDE. These represent an evolution imposing stricter limits on vehicle pollutant emissions, phased as Euro 6A (mandatory from January 2016), Euro 6B (with further particulate reductions), Euro 6C (mandatory from September 2018), Euro 6 Temp (mandatory from September 2019), and Euro 6D (mandatory for registrations from January 2021).
Recent regulatory updates include Regulation (EU) 2017/1151, amending Regulation (EC) No 715/2007 on type approval of passenger and light commercial vehicles emissions, and Regulation (EU) 2018/858, establishing a revised framework for vehicle approval and amending Regulations (EC) No 715/2007 and (EC) No 595/2009 on heavy-duty vehicle emissions (Euro VI). Additional directives regulate emissions from “off-road” vehicles (rail and inland waterways).
Emissions from ships and aircraft are governed by international organizations (IMO and ICAO), with possible stricter regulations in certain zones. Since January 1, 2020, the IMO’s new regulation limits marine fuel sulfur content to 0.5% (down from 3.5%), less stringent than the 0.1% limit in SECA (Sulfur Emission Control Areas) established in 2015.
Descrizione 2
EMEP/EEA air pollutant emission inventory guidebook 2019, EEA Report No 13/2019 (https://www.eea.europa.eu/publications/emep-eea-guidebook-2019)
ISPRA 2024, Italian Emission Inventory 1990-2022: Informative Inventory Report*, Report No. 400/2024 (https://emissioni.sina.isprambiente.it/inventario-nazionale/)
Estimates of emissions calculated at a national average level may not precisely reflect the situation observed at the local scale; in particular, regarding the spatialization methodology adopted for road transport, the effects of the higher prevalence of newer vehicles compliant with the latest anti-pollution standards in Northern Italy are not accounted for.
-
Qualificazione dati
ISPRA: https://emissioni.sina.isprambiente.it/inventario-nazionale/
National
1990 - 2022
Qualificazione indicatore
The estimation of pollutant emissions from transport is based on the methodology described in the EMEP/EEA Air Pollutant Emission Inventory Guidebook, the technical reference adopted at European level for the preparation of national emission inventories reported under the UNECE Convention on Long-range Transboundary Air Pollution (CLRTAP) and the EU NEC Directive. Estimates are generated using appropriate emission factors and advanced computational algorithms that require, in turn, the availability of extensive input data—for road transport, for example: vehicle fleet composition, estimated annual mileage and average speeds, and detailed specifications on vehicle technology, fuel types, and driving modes by vehicle category, engine size or weight class, Euro emission standard, and fuel used. For road transport emissions, the COPERT model—endorsed at European level—is applied.
The current assessment is considered poor, due to the rebound in emissions observed following the pandemic crisis—most notably in 2021 and 2022—and fundamentally because of the ongoing critical issues characterizing the transport sector in terms of emissions. These include the significant share of transport in the national total for many air pollutants, the predominance of road transport, the ongoing discrepancies between type-approval emission values and real-world on-road emissions, and the uncertainties associated with the estimation methodologies.
A positive assessment is attributed to the trend, due to the overall progress observed over the years in the reduction of atmospheric pollutant emissions. In Italy, emissions from the transport sector for the pollutants under consideration show a decreasing pattern. In particular, harmful emissions from road transport have significantly declined in recent years, mainly due to the introduction of catalytic converters, particulate filters, and other vehicle technologies—such as canisters aimed at reducing evaporative emissions. The introduction of unleaded petrol has also led to a substantial reduction in lead emissions. Sulphur oxide emissions, now almost absent from road transport, remain significant in maritime transport.
Dati
Figure 1: Non-Methane Volatile Organic Compounds (NMVOC) Emissions from Road Transport in 2022.
ISPRA (Italian National Institute for Environmental Protection and Research)
Figure 2: Nitrogen Oxides (NOₓ) Emissions from Road Transport in 2022.
ISPRA (Italian National Institute for Environmental Protection and Research)
Figure 3: PM₂.₅ Emissions from Road Transport in 2022.
ISPRA (Italian National Institute for Environmental Protection and Research)
Table 1: Benzene Emissions from the Transport Sector, by Mode of Transport
ISPRA (Italian National Institute for Environmental Protection and Research)
The data are derived from the National Air Pollutant Emission Inventory. The time series has been recalculated to reflect the annual inventory update.
Table 2: PM2.5 Emissions from the Transport Sector, by Mode of Transport
ISPRA (Italian National Institute for Environmental Protection and Research)
Data are derived from the National Inventory of Atmospheric Pollutant Emissions. The historical time series has been recalculated in line with the annual inventory update. Emissions from tire wear, brake abrasion, and road surface wear are accounted for separately.
Table 3: Sulphur oxides (SOₓ) emissions from the transport sector, by transport mode
ISPRA (Italian National Institute for Environmental Protection and Research)
The data are sourced from the National Air Pollutant Emission Inventory. The time series has been recalculated in accordance with the annual inventory update.
Table 4: Nitrogen Oxides (NOₓ) Emissions from the Transport Sector, by Mode of Transport
ISPRA (Italian National Institute for Environmental Protection and Research)
The data are derived from the National Air Pollutant Emission Inventory. The historical time series has been recalculated in accordance with the annual inventory update.
Table 5: Non-Methane Volatile Organic Compounds (NMVOCs) Emissions from the Transport Sector, by Mode of Transport
ISPRA (Italian National Institute for Environmental Protection and Research)
The data are derived from the National Air Pollutant Emission Inventory. The historical time series has been recalculated in accordance with the annual update of the Inventory.
Table 6: Lead Emissions from the Transport Sector, by Mode of Transport
ISPRA (Italian National Institute for Environmental Protection and Research)
The data are derived from the National Air Pollutant Emission Inventory. The historical time series has been recalculated in accordance with the annual update of the Inventory.
Table 7: Percentage Distribution of Selected Pollutant Emissions by Traffic Type
ISPRA (Italian National Institute for Environmental Protection and Research)
The historical time series has been recalculated in accordance with the annual update of the Inventory.
The emission estimation methodology has been updated over the years; in particular, the contribution from road traffic has been revised several times based on the results of on-road vehicle testing. In most cases, emissions rebounded in 2021 and 2022 compared to 2020, when a marked decline—more pronounced for passenger transport than for freight—was essentially attributable to the pandemic crisis.
From the data reported in Tables 1 to 6 for each of the main pollutants, the following observations can be made:
The most significant reduction in emissions was observed for lead, with a 99.0% decrease from 1990 to 2022. This near-elimination is primarily due to the market withdrawal, as of 2002, of leaded petrol containing tetraethyl lead for road transport (Table 6). In 2022, lead emissions increased by 6.1% compared to the previous year. Analysis by vehicle type shows that current emissions mainly originate from tyre and brake wear (97.0%).
Benzene emissions decreased by 96.6% over the 1990–2022 period, thanks to the reduction of benzene content in petrol and the widespread use of catalytic converters (Table 1). However, total current emissions of this recognized carcinogen remain significant, primarily due to the circulation of vehicles without catalytic converters or equipped with outdated systems, two-wheeled vehicles, and maritime activities. In 2022, benzene emissions decreased by 3.7% compared to 2021. Source-specific analysis shows that the largest share comes from passenger cars (42.7%), followed by mopeds and motorcycles (23.1%) and maritime activities (14.3%).
Non-methane volatile organic compound (NMVOC) emissions (Table 5 and Figure 1) declined by 87.4% from 1990 to 2022. However, a 1.1% increase is estimated for 2022 compared to the previous year. Analysis by vehicle type shows that the major contributors are evaporative emissions from petrol engines (47.3%), mopeds and motorcycles (24.5%), passenger cars (13.2%), and maritime activities (10.5%) (Table 5).
Fine particulate matter (PM2.5) emissions (Table 2 and Figure 3) declined by 65.7% over the considered period. However, there was a 10.6% increase in 2022. That year, the main contributors to PM2.5 emissions were maritime activities (37.4%), wear and abrasion from tyres, brakes, and road surfaces (36.1%), and passenger cars (12.3%) (Table 2). Overall, the transport sector contributed 15.6% of national primary PM2.5 emissions in 2022, amounting to 144 kt.
In 2022, nitrogen oxides (NOₓ) emissions from the transport sector (Table 4 and Figure 2) decreased by 67.2% compared to 1990. However, between 2021 and 2022, emissions increased by 7.4%. In 2022, the main contributors were passenger cars (33.7%), maritime transport (28.9%), and heavy-duty vehicles over 3.5 tonnes and buses (22.9%). Transport remains the largest source of national NOₓ emissions, contributing 59.5% of the total 620.1 kt emitted in 2022.
Sulphur oxides (SOₓ) emissions have declined over the years due to reduced sulphur content in fuels. Over the reference period, emissions from transport (Table 4) decreased by 94.3%, though they increased by 50.9% in 2022. The main source is maritime transport, accounting for 91.3% of transport-related SOₓ emissions in 2022. The sector contributed 13.6% of total national emissions, which amounted to 88.1 kt.
Regarding the breakdown of emissions between freight and passenger transport (Table 7), the data vary depending on the pollutant and must be analysed individually:
In 2022, passenger transport accounted for 40.6% of NOₓ emissions, while freight transport contributed 58.4%, making it the main source. Passenger transport had been the main contributor until 1999; however, from 2000 onward, freight transport took over, due to the slower renewal of the vehicle fleet and the less stringent emission reduction requirements for heavy-duty vehicles.
For NMVOCs, passenger transport remains the dominant source (85.8% in 2022), primarily due to passenger cars and two-wheeled vehicles (Table 5). Freight transport accounted for 13.5% of total NMVOC emissions from transport in 2022.
For PM2.5, freight transport contributed 56.9% of transport-related emissions in 2022. Between 2013 and 2017, a slight decline in the freight share was observed, due to the increased share of diesel passenger cars and the significant emission reductions from Euro IV and newer freight vehicles. From 2018 to 2020, the freight share increased again, while the last two years show a slight decrease. The implementation of Euro 6 (passenger) and Euro VI (freight) standards continues to reduce overall diesel vehicle emissions in both sub-sectors.