Mapping Sources of Fine Metallic Particles Near Schools in Greater Paris Using Passive Biocaptors: transforming environmental monitoring practices

As of 2024, 100% of Parisian residents remain exposed to concentrations of fine particulate matter (PM₂.₅) that exceed the World Health Organization’s (WHO) guideline limit of 5 µg/m³. Despite gradual improvements in air quality, atmospheric pollution—particularly from fine particles and nitrogen dioxide (NO₂)—continues to pose a major public health challenge. Recent findings by the French association Respire revealed that 682 daycare centers and schools in Île-de-France (Administrative region of Paris) exceed WHO NO₂ thresholds, underscoring the urgent need for intervention and the increasing mobilization of local stakeholders.In the Paris region, wood heating and road traffic are the primary sources of fine particulate matter. Ultrafine particles (