Search

The current air quality situation in Europe is reviewed for the most critical pollutants, i.e.: PM10, PM2.5, N02, 03 and BaP. Reasons of incompliance, as well as major actions required for reaching further compliance of the WHO guidelines are discussed. For some pollutants there is a need for further scientific research in order to cost-efficiently abate urban and peri-urban pollution, especially for PMx and03. The policy and scientific challenges are identified for these five pollutants. These include, for policy, the need to solve the air quality problem caused by NOx-diesel-vehicle EU policy failure, the need to reduce PM and BaP emissions from an increasing domestic biomass burning combustion favoured by policy actions, the need to abate the currently high agricultural NH3 emissions, and devising specific and cost-effective 03 abatement strategies. Key scientific challenges include the need for an accurate source apportionment of secondary organic aerosols in urban areas, the abatement of vehicle wear and road dust resuspension, an accurate tropospheric 03 source apportionment identifying the hemispheric/regional/local contributions as well as the accurate modelling of 03 able to reproduce the complex meteorology favouring high 03 episodes around the Mediterranean, and yielding reliable sensitivity analysis for policy actions. Levels, origins and application of other non-regulated air quality parameters such as concentrations of ultrafine particles (UFP) and black carbon (BC) are discussed in view of their potential use in air quality standards. We conclude that monitoring of BC should provide accurate evaluations of the effectiveness of road traffic air quality measures and their associated health gains. In the case of UFP, although road traffic is the major contributing source to urban levels, in high insolation regions a significant fraction of urban UFP can be attributed to photochemical nucleation processes. Thus, caution is necessary when doing metaanalysis of health outcomes linked to urban UFP using data from diverse cities, where the finest aerosol fraction might be considerably different in both composition and origin. Finally a strategy to abate N02 and PM from road traffic in urban areas of Europe, based on 7 major pillars or action types, is presented. [ABSTRACT FROM AUTHOR]