Ecorc’Air, the urban pollution measured in the bark of plane trees
Ecorc'Air, a participatory science project run by several institutions, aims to collect plane tree bark in order to establish a precise map of fine metal particle pollution linked to automobile traffic, and to measure its evolution. In Paris, samples can be delivered to the IPGP, where magnetic and chemical analyses will be carried out to detect this pollution.
Publication date: 15/04/2021
General public, Press, Research
Related teams :
Paleomagnetism
Related themes : Earth System Science
The Ecorc’Air project, which involves the University of Toulouse, Sorbonne University, MINES ParisTech and the Institut de Physique du Globe de Paris, was launched in 2016 with a sampling campaign in Paris, aimed at mapping and measuring changes in fine metallic particle pollution linked mainly to car traffic. Since this year, Ecorc’Air has been expanding and has joined the PartiCitaE participatory science platform. A simple protocol has been drawn up so that city dwellers who wish to do so can collect plane tree bark in their neighbourhood.
Because of their frequent presence along roadsides and boulevards, plane trees offer great potential for sampling pollution. Particles, emitted mainly by brakes, tyres and vehicle exhaust, become embedded in the porous bark of trees and remain trapped there. As plane trees have bark that ‘peels’ every year, it is easy to harvest the bark without risk to the tree, and to obtain a sample of the pollution accumulated over the year.
Traffic-related pollution is then measured in the laboratory using magnetic measurements of the samples taken. These highly sensitive measurements enable the iron oxide nanoparticles produced by car traffic to be detected and quantified precisely. The annual measurement campaigns allow us to see how pollution changes over time.
Geochemical methods for detecting nanoparticles will also be used to extend the measurements to non-iron pollutants, thereby diversifying and refining the pollution map. New techniques are being developed to successfully differentiate between elements resulting from pollution, in the form of fine polluting particles, and these same elements that may be naturally present in other forms in the samples. The IPGP teams are currently working on a thesis on this subject.
All the information on harvesting plane tree bark is available on the Paris City Council website: https: //www.paris.fr/dossiers/volontaire-du-climat-7#j-agis-pour-le-climat
To find out more about the Ecorc’Air project:
