Articles | Volume 4, issue 2
https://doi.org/10.5194/ar-4-547-2026
https://doi.org/10.5194/ar-4-547-2026
Research article
 | 
04 Nov 2026
Research article |  | 04 Nov 2026

Inhalation of small particles (PM2.5) in urban road tunnels and underground in Madrid (Spain) – a citizen science project

Ángel López-Encuentra, Esther Gil Cid, and Luis Miguel Pozo Coronado

Data sets

September 18, 2026 (v1)PublicationOpen INHALATION OF SMALL PARTICLES (PM2.5) IN URBAN ROAD TUNNELS 1 AND UNDERGROUND IN MADRID (SPAIN). A CITIZEN SCIENCE PROJECT Angel Lopez-Encuentra https://doi.org/10.5281/zenodo.22833044

Download
Short summary
In road tunnels and the metro, there are small toxic airborne particles (PM2.5). In Madrid (Spain), there is no public information on PM2.5 in these infrastructures. One alternative is for citizen scientists to use validated low-cost sensors. Data from these sensors were compared with reference station data; their correlation was high. PM2.5 levels in Madrid’s tunnels and metro exceed 10 µg m–3 and are above the 2011 World Health Organization guideline.
Share
Altmetrics
Final-revised paper
Preprint