Advanced transport emissions monitoring networks
Transport emissions are a known cause of air and noise pollution in Europe, and therefore negative health impacts, particularly in urban environments. Road emissions play a significant part, but there can be important contributions by other transport sources if airports, ports, or rail stations with significant traffic from diesel locomotives are within or close to the city boundaries. Moreover, construction machinery can largely contribute to both emissions and noise where large building sites are present.
Long-term exposure to air pollutants from road traffic, railways and aircrafts can lead to serious health effects, such as sleep disturbance, cardiovascular diseases, metabolic disorders, annoyance, cognitive impairment and mental health problems. Noise pollution has its share of causing those health impacts and is an equally important environmental concern, likewise emitted by means of transport (road, rail, air traffic) and from sites of industrial activity. Besides the combustion engine, it can also be caused by aerodynamics or tyre-road or wheel-rail interactions. It adversely affects quality of life and well-being, prompting the need for seeking solutions to tackle these two forms of environmental pollution in order to reduce their harmful effects on human health and on the natural environment.
While some of these emissions are regulated, it has become apparent that the performance of propulsion and after treatment systems can change depending on use conditions or over time due to different causes (poor or even fraudulent design, tampering by the user, poor maintenance, catalyst degradation …). Therefore, there is more and more interest to monitor these pollutant and noise emissions to the level of the individual vehicle and their cumulative effect at the city scale in order to provide a sound basis to understand the causes and to tackle, if needed, higher-than-expected emissions by enforcement or regulatory means.
Traffic-related particles can be distinguished into exhaust traffic related particles, which are emitted as a result of incomplete fuel combustion and lubricant volatilisation during the combustion procedure, and non-exhaust traffic related particles, which are either generated from non-exhaust traffic related sources such as brake, tyre, clutch and road surface wear or already exist in the environment as deposited material and become re-suspended due to traffic induced turbulence. It is estimated that exhaust and non-exhaust sources contribute significantly to total traffic related PM10 emissions, thus it is important to monitor both these categories of pollutant emissions, while differentiating their contribution to PN.
The Flagship on the contribution of transport to pollution in the 2019 call has included several topics addressing the development of technologies to monitor some of these emissions, and it is now important to transfer these technologies to the field and to integrate them in networks capable of 24/7 unassisted operation and data management and reporting for enforcement and fleet monitoring by cities and national bodies, and where appropriate shared with EU level bodies.
The design, testing and demonstration of these applications will be developed in cooperation with the involved cities, citizen associations, and authorities, to achieve the best use of monitoring data. Citizen science approach could be appropriate for these activities.
Projects are expected to install monitoring stations around at least 5 ports and 5 airports, allowing for instance to monitor and enforce the respect of fuel use mandates, correct noise abatement procedures, aircraft type limitations, etc. Projects should achieve synergies between the monitored cities, ports and airports.
At the same time, recent WHO guidance[[ https://apps.who.int/iris/handle/10665/345329]] recognised the specific risks posed by nanoparticles and provided for the first time a quantification of what can be considered a low and a high concentration of particles in terms of numbers instead of mass. Guidance was also provided to widen the collection of data to ultrafine particles down to at least 10nm, in order to allow the performance of epidemiological studies and, in the longer term, the establishment of new limit values.
Moreover, emerging pollutants and greenhouse gases are increasing due to the deployment of new technologies. Nitrous oxide, for instance, is both a very potent GHG and a neurotoxic with negative effects also on liver and kidneys and is a by-product of several catalysts. Ammonia is also posing similar by-product issues, in particular for methane and SCR-equipped vehicles, by leading to high secondary particulate levels. Therefore, monitoring these and other chemicals and their synergistic effects is becoming more and more important to inform policy decisions and provide data for modelling and emissions inventories.
A specific topic in the 2020 Green Deal call[[ https://cordis.europa.eu/programme/id/H2020_LC-GD-9-1-2020 and projects https://cordis.europa.eu/project/id/101037319 and https://cordis.europa.eu/project/id/101036245]] foresaw the developments of measurement instruments and methodologies for ambient ultrafine particles and atmospheric particulate matter, their sizes, constituents, source contributions and gaseous precursors. The wider deployment of the results on a cross-European base, encompassing as many as possible different locations in terms of urban morphology and meteorological and pollution conditions is paramount for the validation of the system and for the establishment of an EU-wide network.
Establishing, or contributing to, national level databases of traffic related emissions could support population-based health studies about the impact of these emissions to human health. These databases could, for example, contain detailed information on traffic density, modal split, current composition of the respective road traffic fleet, especially in urban areas, and all health relevant pollutants, such as particles (PM10, PM2.5 PN), NOx, benzene and UFP/EC/BC.
In consideration of the above, proposals should address all the aforementioned aspects and issues in order to achieve the expected outcomes.