Source Apportionment

About the source apportionment

Quantitative and reliable estimations of pollution sources obtained with harmonised methods could be an invaluable support for obligations under the EU Air Quality Directive 2008/50/EC (e.g. air quality assessment, action plans drafting, identification of long range/transboundary transport, etc...).

Source Apportionment (SA) is the practice of deriving information about pollution sources and the amount they contribute to ambient air pollution levels. This task can be accomplished using emission inventories, source-oriented models and receptor-oriented models (or simply receptor models).

Receptor models have been extensively used for the apportionment of air pollution sources in the last three decades. They rely on mass balance analysis and statistical evaluation of chemical data obtained at the receptor site (typically PM). Despite several receptor models have been developed and adjusted, all of them present strengths and weaknesses. Many factors like size of the database, sampling me thodology, time resolution, site selection, uncertainty estimation, among others, may influence the model performance.

In order to improve the comparability of results from different approaches and to constrain the output's uncertainty, the JRC launched an initiative for the harmonisation of source apportionment with receptor models in collaboration with the European networks in the field of air quality modelling (FAIRMODE) and measurements (AQUILA).

The activities carried out are:

  • review of the methodologies used in Europe for source identification,
  • intercomparison exercises for the quantitative assessment of the performance of SA models,
  • drafting an European Common Protocol for SA with receptor models;

receptor models schema

Workshops involving experts from different European research groups gathered once a year to present new developments in the field, discuss about controversial aspects of receptor models, present the progress of the activities and plan future work