“Three stations have exceeded the high threshold for fine particles proposed by Anses,” warns Pierre Pernot, engineer at Airparif.
Who has never waited for long minutes for a metro on a crowded and airless platform? Last spring, the Paris prosecutor’s office opened investigation for “endangering others” targeting the RATP, suspected by the Respire association of hiding an abnormally high level of fine particles from its users. To overcome the lack of reliable data on the subject and for the first time, Airparif, responsible for monitoring air quality in Île-de-France, and Île-de-France Mobilités unveil the map metro, RER and Transilien platforms the most polluted.
3 levels of pollution
The organization has compiled data on levels of fine particles measured by RATP and SNCF between 2015 and 2022 in 44 underground stations. These data were then compared to the thresholds of the National Agency for Food, Environmental and Occupational Health Safety (ANSES) for air quality on the platforms of underground railway enclosures to assess the levels. of pollution during an exposure time of one hour. These stations were then classified according to 3 levels : in Green (little polluted), in YELLOW (average pollution) and red (very polluted). Real disparities exist. On 44 station platforms that could be documented (out of the 397 stations in the Ile-de-France network in total):
- 3 stations present levels of high pollution (exceeding a fine particle rate of 480µg/m³)
- 31 stations present levels of average pollution (a rate of fine particles between 140 and 480µg/m³)
- 10 stations present levels of low pollution (a particle rate lower than 140 µg/m³)
What health risks?
Very small fine particles (PM10 and PM2.5) would be produced when trains brake, when they arrive at a station. And it is the finest particles that are the most harmful to health. Regular exposure can increase risk”dinflammation of the respiratory tractparticularly in sensitive populations such as asthmatics” Or “of effects on autonomic cardiac function“, suggests Anses in a January 2023 opinion. “Three stations exceeded the high threshold (fine particles, editor’s note) proposed by ANSES“, warns Pierre Pernot, engineer at Airparif. The three stations are located on the Right Bank, in the North-East of Paris. They are Jaurès (platform of line 5), Belleville (platform of line 11) and Oberkampf (line 5 platform). Oberkampf was equipped with new ventilation at the beginning of December 2023. But for the other 2, there is still work to be done.”We will be able to strengthen and even create fans on the three stations concerned. Jaurès and Belleville will move to orange, otherwise green at the end of 2024“, guarantees Laurent Probst, general director of Ile-de-France Mobilités. new system reducing emissions of fine particles generated when trains brake would also be considered, particularly on RER A and metro lines 1, 2, 3, 4, 5 and 9.
“The particles are not the same in the trains”
“The work communicated by Airparif and IDFM does not reflect the exposure of travelers or employees”specifies Sophie Mazoué, sustainable development manager for the RATP group on Europe 1who according to her, no user or employee stays on a platform for an hour. Due to a lack of scientific data, it is currently difficult to say what the real health risks are when you stay 5 or 10 minutes on a platform. The data is expected to evolve: a precise map of the 397 metro and RER stations as well as data at train level will be available in June 2024. “The particles are not the same in the trains and on the platforms. In general, it is a little lower in the trains because the air is ventilated. We will have the verification in June”continues Laurent Probst.