For the first time, ACTRIS and RI-URBANS have joined forces to harmonize how scientists measure the oxidative potential (OP) of airborne particles which is a health-relevant metric that quantifies how particulate matter can trigger oxidative stress in the lungs.

Within RI-URBANS, European researchers worked together to adopt simplified harmonized protocols. In 2023, an intercomparison exercise for the DTT method involved 18 labs globally; results were processed by the European Joint Research Centre (JRC). The next step, launched in early 2025, focused on the AA (ascorbic acid ) assay: 26 laboratories tested five common samples under the harmonized procedure, also comparing against their own “home” AA method. The DTT (dithiothreitol) method was included for cross-comparison.

Next steps

ACTRIS and RI-URBANS partners are now investigating sources of remaining discrepancies. A third stage will revisit the simplified DTT protocol to assess progress. Ultimately, these efforts aim to have OP included as a labelled ACTRIS variable, serving both research and operational air-quality/health applications. see more details on ACTRIS

For more details: contact gaelle.uzu@univ-grenoble-alpes.fr or anouk.marsal@univ-grenoble-alpes.fr.