Air quality measured at Châtelet RER A station

RATP continuously monitors and assesses air quality in underground rail enclosures. Surveillance is based primarily on the hygiene and cleanliness of RATP’s spaces, both for travellers and for staff. The RATP laboratory conducts continuous measurements at 5 stations representative of the RATP’s underground spaces (Châtelet, Franklin Roosevelt and Auber, Châtelet RER A and Nation RER A) that make up the Squales network (Underground Environment Air Quality Monitoring). This data set corresponds to station Châtelet on line A of the RER. The measurements cover the usual climatic parameters (temperature, relative humidity), air change (carbon dioxide) and air quality (nitrogen oxides, particulates). This network automatically produces more than 200,000 raw data per year. The hourly averages of these measures are the published database. Spot measurement campaigns also allow monitoring for other parameters, such as ultrafine particles, aldehydes, monocyclic or polycyclic aromatic hydrocarbons.