according to ANSES, the concentration of fine particles is three times higher in the metro than outside

If taking the metro makes it possible to pollute less, the quality of underground air is poor, according to the National Health Security Agency (ANSES). She studied it in six cities: Paris, Lyon (Rhône), Marseille (Bouches-du-Rhône), Lille (Nord), Toulouse (Haute-Garonne) and Rennes (Ille-et-Vilaine) and noted that the particle concentration is three times higher there than outside. The polluting particles come from the friction of the rolling stock with the rails, as well as from braking.

In Paris, the RATP is working to reduce emissions in the metro. “Braking systems are indeed being improved to reduce emissions at source“, says Sophie Mazoué, sustainable development manager at RATP. She points out that particle sensors have also been installed. However, particle rates have not varied since 2015, according to ANSES. “We measured a lot of very fine particles, which are particles that enter the body, and attack our organs“, assures Tony Renucci, general manager of the association “Respire”.