A new international study led by researchers from the Institute of Environmental Assessment and Water Research (IDAEA-CSIC) and  Guangdong University of Technology, in collaboration with over 20 European institutions, has delivered the most comprehensive source apportionment analysis of PM10 pollution in Europe to date.

Published in npj Climate and Atmospheric Science, the study analyzed multi-year chemical speciation data from 24 monitoring sites across six European countries—France, Greece, Italy, Portugal, Spain, and Switzerland—using a harmonized Positive Matrix Factorization (PMF) model. This uniform approach allows direct comparison of pollution sources across diverse urban environments.

Seven major sources of PM10 were identified: road traffic, biomass burning, crustal/mineral dust, secondary aerosols, industrial emissions, sea salt, and heavy oil combustion (HOC). Among them, road traffic emerged as the leading contributor in most urban areas, accounting for up to 41% of PM10 concentrations in high-traffic zones. Biomass burning was widespread, especially in winter, with contributions reaching 40% at some sites. Secondary aerosols—largely formed through chemical reactions in the atmosphere—were also significant, representing up to 68% of PM10 at certain locations.

One key insight from the study is that source profiles such as traffic, sea salt, and secondary aerosols were chemically consistent across sites, whereas industrial, crustal, and HOC sources showed substantial local variability. The research also highlighted the limitations of missing key chemical tracers (e.g., levoglucosan), which can reduce source resolution at some locations.

This work is a major contribution to the RI-URBANS initiative, which aims to enhance urban air quality management by bridging cutting-edge research with practical implementation in European cities. By standardizing methodologies and improving data comparability, the study supports more targeted and effective air pollution control strategies.

Learn more about this collaborative study led by Xiansheng Liu from Guangdong University of Technology here .