AIREAL- Nantes, France

Status: Concluded.

Nantes-based non-profit Air Pays de La Loire carried out the project AIREAL to identify and test solutions to reduce residents' exposure to air pollution. Working together with Nantes Metropole and local innovation centre SAMOA, Air Pays de la Loire identified local test beds to implement measures – air quality management interventions – and trial solutions to evaluate air quality in public spaces.

Using existing data on weather, background pollution and real-time traffic, the AIREAL developed a mobile application called Naonair to provide live data on different air pollutants (namely on PM10, PM2.5, ozone, nitrogen dioxide and sulphur dioxide) to guide users on healthier ways to move and live. The app is available only in Nantes and can be downloaded on the App and Google Stores.




The app supports pedestrians and bikers who need to commute or wish to stroll or relax outdoors. Users can navigate the interface to self-locate and move around the map to see the air quality in the metropolitan area. Pollutant levels are represented by a graded colour scale, ranging from green (good) to purple (extremely bad); the application provides users with both ‘healthier’ and ‘faster’ route options. In addition, it is possible to check the air quality at emblematic places in the city, such as cultural places, sports venues, local parks, etc.

Before the public launch, 30 beta testers used the application over the summer, and reported their feedback back to the development team.


  • Real-time traffic data is collected from the Nantes Métropole and the Interdepartmental Directorate of Roads West (Direction Interdépartementale des Routes Ouest) counting terminals present on a large part of the metropolitan road network.
  • The processing of this data then makes it possible to build a “traffic” database in real time, linked to the project network. T
  • Each axis of the road network corresponds to traffic information to be translated into pollutant emissions, then into concentrations of pollutants in the air to ultimately provide a real-time map of air quality throughout the territory.
  • These different levels of data processing call on advanced calculation tools, used on a daily basis by our design engineers and modelling experts, and take into account a panel of complementary data (inventory of emissions, weather , background pollution, etc.).

Urban experiments



With support from Nantes Metropole and the local innovation lab Samoa, Air Pays de La Loire implemented the Aireal project in three main steps: the design of a tool with territorial and existing data; the implementation of urban experiments; and, finally, the development of the application.

Samoa – who were responsible for testing the approach in public space and the applicability of the model developed – installed an urban experiment in the “Île de Nantes” area, aimed at making air quality a concrete subject in everyday life. Connected visual panels were installed on the Anne de Bretagne bridge in the centre of Nantes, which informed drivers, cyclists and pedestrians about the air quality at that location in real time. Based on local air information, citizens could adapt their behaviour and routes to reduce exposure to pollution. The experiment was ongoing from May to September 2022, and Samoa will now conduct analysis to check its impact on people’s behaviour.

Pictures below are from Céline Jacq/Nantes Metropole


Air Pays de la Loire



Based in the French city of Nantes, Air Pays de la Loire is a non-profit organisation responsible for monitoring and informing about air quality in the Pays de la Loire region. Its missions include consulting about design, implementation and evaluation of public policies. Air Pays de la Loire also works with industries to assess impacts of their installations and with research institutions to conduct innovative projects.

AIREAL's proposal was selected to receive funding through the ICLEI Action Fund due to its strong technological component and data-driven approach, by providing real time air pollution data for enhanced decision making from Municipality (traffic management) and citizens (health protection), which confers to the project a potential for high impact.