Analyse exploratoire des mesures de particules ultrafines en temps réel dans des enceintes ferroviaires souterraines de transport public

ContextAmong the many airborne pollutants in an underground railway environment, ultrafine particles (UFPs, diameter < 100 nm) are the least documented. The objective was to study the exposure to UFPs for jobs occurring in an underground railway and to explore the determinants of its variability.MethodsThree station agents, three locomotive operators and three security guards were followed-up in their daily activities over two consecutive weeks. UFPs number concentrations were measured in their personal breathing zone (PBZ) using DiSCmini. Occupied environments and events occurring during agents’ occupational activity were reported in an activity logbook. The effect of these determinants on UFPs exposure was analyzed for each job using graphical analyses and a mixed regression model.ResultsUFPs number concentration means registered for each job appear significantly associated with the environment that agents were occupying during their work shifts: 3.4 (± 0.6) × 103 particles/cm3 in the security guards changing room; 9.5 (± 1.7) × 103 particles/cm3 in the station break rooms; 15.9 (± 2.4) × 103 particles/cm3 in the station underground corridors; 17.3 (± 4.4) × 103 particles/cm3 on the subway platform; and 23.5 (± 6.2) × 103 particles/cm3 on the railways. However, no association was found between these concentration levels and the occurrence of events (e.g. subway passage, information office door opening).ConclusionAgents’ UFPs exposure levels are associated with the occupational environment they work. Time-series analysis confirms these results and allows a further understanding of exposure and its determinants. ContexteParmi les composants particulaires constituant l’air des enceintes ferroviaires souterraines (EFS), les particules ultrafines (PUF, diamètre < 100 nm) restent à ce jour les plus faiblement documentées. L’objectif était d’examiner l’exposition aux PUF pour les trois principaux métiers présents dans les EFS (agents de station, conducteurs, agents de sécurité) et d’explorer les déterminants de sa variabilité.MéthodologieTrois agents de station, trois conducteurs de métro et trois agents de sécurité ont été suivis au quotidien pendant deux semaines consécutives. Les concentrations en nombre des PUF dans leur zone respiratoire ont été mesurées au moyen d’appareils DiSCmini. Les environnements occupés et les évènements survenus au cours de leur activité professionnelle ont été notifiés dans un journal d’activité. L’effet de ces déterminants sur l