Chapter 43 Application of a Comprehensive Integrated Assessment Tool for the Brussels Capital Region Peter Viaene, Enrico Turrini, Claudio Carnevale, Marialuisa Volta, Roberta Gianfreda, Guiseppe Maffeis, Priscilla Declerck, Olivier Brasseur, Pieter Valkering and Clemens Mensink Abstract While in general air quality has improved in Europe over the past dec- ades, there are still problems with exceedances of ambient air quality limit values in many urban areas. To design ef ficient Air Quality Plans to face these problems, methodologies and tools are required to assess the effects of possible abatement measures on local air quality. One such tool is RIAT+ (http://www.riatplus.eu) which was designed to help regional decision makers select air pollution reduction policies that will improve the air quality at minimal costs. In this contribution to ITM we present the results obtained as well as the lessons learned for an application of the RIAT+ tool to the Brussels Capital Region. RIAT+ has been previously applied successfully to regions in the Po Valley in Italy and to the Alsace region in France. The application to the BCR however poses specific challenges due to the fact that both the area on which the abatement measures can be applied as the emissions are more limited than in previous cases. Inside the BCR, emissions of nitrogen oxide and particulate matter are mainly from non-industrial combustion and traf fic. For these two source categories a list of possible air quality abatement measures was provided by the Brussels Environmental agency. To allow RIAT+ to determine the optimal combination of abatement measures with minimal cost, information was collected on both the emission reduction ef ficiency and the costs of P. Viaene ( ✉ ) ⋅ P. Valkering ⋅ C. Mensink VITO, Boeretang 200, 2400 Mol, Belgium e-mail: peter.viaene@vito.be C. Mensink e-mail: clemens.mensink@vito.be E. Turrini ⋅ C. Carnevale ⋅ M. Volta UNIBS, Via Branze 38, 25123 Brescia, Italy e-mail: claudio.carnevale@unibs.it R. Gianfreda ⋅ G. Maffeis TerrAria s.r.l., via Melchiorre Gioia 132, 20125 Milan, Italy P. Declerck ⋅ O. Brasseur Brussels Environment, Thurn & Taxis Havenlaan 86C/3000, 1000 Brussels, Belgium © Springer International Publishing AG 2018 C. Mensink and G. Kallos (eds.), Air Pollution Modeling and its Application XXV, Springer Proceedings in Complexity, DOI 10.1007/978-3-319-57645-9_43 275