Challenges for a New Air Quality Directive: The role of monitoring and modelling techniques

Air pollution is a major environmental health problem. The current Directive 2008/50/EC on ambient air quality and cleaner air for Europe establishes the need to reduce pollution to levels which minimise harmful effects on human health, paying particular attention to sensitive populations, and the environment as a whole, to improve the monitoring and assessment of air quality including the deposition of pollutants and to provide information to the public.This work presents an overview of the major guidelines of the Air Quality Directive concerning modelling and monitoring techniques and of current European initiatives on the subject. Also identifies the new challenges for the forthcoming directive, namely on the combined use of monitoring and modelling techniques and also on human exposure assessment. These challenges are illustrated by novel monitoring and modelling assessment approaches and innovative exposure assessment methodologies, for which selected examples are provided.A methodology to use monitoring data to improve AQ modelling performance was proposed using a set of statistical methods of data fusion, in which the bias correction technique RAT04 achieve the best performance.Moreover, methodologies based on personal monitoring, with AQ sensors, and/or on human exposure modelling, appear as tools for a more accurate exposure assessment.