Overall definition and context of the topic
Despite considerable progress in the past decades, ambient air pollution remains the number one environmental cause of premature deaths in the EU, still leading to more than 390.000 premature deaths each year in the EU due to elevated levels of fine particles, nitrogen dioxide and ozone. Air pollution also continues to harm ecosystems as more than half of the EU territory is exposed to excess nitrogen deposition (eutrophication) and ozone concentrations. This negatively impacts biodiversity, reduces crop yields and causes other material damage. 
EU environmental policy focusses on developing and implementing a clean air policy framework that reinforces national, regional and local policies in those aspects of air quality problems that Member States cannot handle effectively or efficiently alone. EU policies also aim at implementing the Union's international obligations in the field of air pollution having as main actors citizens, to co-design and co-implement and at integrating environmental protection requirements into, for example, industry, construction, urban planning and design, energy, transport, urban farming and agriculture sectors.
Figures illustrating the importance of ambient air pollution can be found here.

Relevance for and role of urban authorities
Urban authorities are best placed to implement local measures benefiting citizen’s health and well-being and the environment, as they know the local situation and control a range of instruments such as urban planning and design, infrastructure/traffic management, housing permits, neighbourhood retrofit and buildings adaptive re-use, parking policy etc., which allows them to steer and promote innovative solutions. They will generally control local budgets and employ the staff that will have to do any implementation, including for instance taking or enforcing measures in the case of smog episodes, or designing and implementing long-term air quality plans.
In many Member States city authorities are either responsible for developing, implementing and evaluating official air quality plans under Directive 2008/50/EC or for city air quality plans that are linked to official regional air quality plans under Directive 2008/50/EC. In the case of official regional air quality plans, cities often play a major role as they tend to be the big economic centre of the region, with a concentration of population, traffic and industry. The fact that exceedances of PM and NO2 in many cities of several countries persist, despite air quality action plans, indicate that innovative solutions and improvements in the approach are necessary: a better insight in where and when the air pollution problems may occur and how innovative solutions can contribute to solutions would be very welcome. 

Prompts for urban authorities
It should be stressed that healthy living and urban air quality can be improved by mitigation of the relevant emission sources of air pollutants or their precursors. Urban air quality is not only influenced by urban sources (i.e. traffic, domestic heating, poorly isolated buildings, industry) but also by sources situated outside the city. This so-called background air quality is composed of/influenced by the emissions from non-urban emission sources such as agriculture, (inland) shipping, natural sources and emissions in distant (urban) areas. Decisions on which urban source could best (cost-effectively) be mitigated require good data on the background sources (which determine the background concentration and the city’s own contribution to air pollution). In addition, air pollution in an urban environment is not homogeneous. In any urban environment hotspots occur, which can be related to various sources. High-resolution modelling could help identifying these hotspots and allow far more precise and more cost-effective measures that are best suited for that micro environment.
When identifying innovative solutions, urban authorities are invited to take note of and build on lessons learnt as described in the reports from the European Environment Agency on air implementation in 12 cities (Air Implementation Pilot, Europe's urban air quality — re-assessing implementation challenges in cities), from projects carried out under the LIFE  or Horizon 2020 (See for instance the urban waste management call 2015 to renature cities ; and most recent cross-cutting activities with focus on smart and sustainable cities)  programmes and, where appropriate, link to existing activities, such as exchanges under the TAIEX Peer-2-Peer programme.
Without being prescriptive in terms of the types of projects expected, cities are invited to consider in particular the following points and issues:

  • Clean commuting: innovative mobility solutions ( e.g Urban Vehicle Access Regulations (UVARs) such as low Emission Zones and/or Congestion Charging)  to reduce the impact of commuter traffic from suburban and other areas surrounding the city (centre) on urban air quality. City authorities could apply results from mobility projects and investments specifically to the challenge of air pollution from commuter traffic, testing and improving innovative solutions to enhance uptake, public acceptance and impact on air pollution. A key element would be the cooperation with regional authorities and neighbouring municipalities as commuting often originates outside the city boundaries and as Air Quality Plans under Directive 2008/50/EC are often established at regional level.
  • Clean air and climate: City authorities are best placed to maximize synergies between energy/climate and air quality measures locally. They could, for instance, test methodologies to integrate air quality into their climate and energy strategies, such as the Sustainable Energy and Climate Action Plans (SECAPs) under the Covenant of Mayors, improving the link to Air Quality Plans, such as developed under the Ambient Air Quality Directives. If and where appropriate, results could be shared in relevant city networks. 
  • Clean air for all: citizens can become more vulnerable to air pollution due to health conditions. Less affluent parts of cities, and thereby their dwellers, can also be more affected by air pollution. Urban authorities could test innovative actions on issues such as urban planning, mobility, energy and information, to target them to reduce air pollution exposure of such vulnerable groups, for instance focusing on less affluent areas with high pollution, and/or on areas with childcare facilities and schools, hospitals and/or homes for the elderly. 
  • Clean air citizen science: use of indicative air quality measurements (e.g. through deployment of reliable low-cost sensors) to complement the official air quality monitoring stations. Urban authorities, where needed together with relevant stakeholders responsible for air quality monitoring and public health, could test and link up citizen science with developed tools for processing data and qualified established air quality monitoring practices, building on experiences with related projects (LIFE Preparatory Project on sensors; EP Pilot Project on sensors) . 
  • Clean air communication: often enjoying high political trust, local authorities are well-placed to increase public acceptance of clean air quality measures, for instance ensuring and demonstrating positive social, health and well-being impacts. Projects should test innovative approaches that adequately target key segments of the local population, such as in schools, the construction sector and the health community, to further sensitise citizens and stimulate behavioural and cultural change.
  • Clean air governance: multi-level and multi-departmental governance best practices. Effective action on air quality depends on all levels of governance, and at every single level on cooperation between departments that can affect air quality (e.g. urban planning and building codes, mobility, road maintenance, urban green, etc.). Projects should design and test innovative approaches to clean air policies across different levels of governance, such as local, regional and national, and across departments.

As this is the second time that the topic of Air Quality is included in a UIA Call for Proposals, we would recommend that applicants look at those projects approved in the third Call for Proposals.