European Directive (2008)
In May 2008, Framework Directive 96/62/EC, the first three daughter directives and a directive on the exchange of information were superseded by new EU Directive 2008/50/EC. The limit and target values and the information and alert thresholds were retained, except for the second phase of the PM10 limit value which was removed. Additionally, based on recent health research into the harmful effects of PM2.5, monitoring requirements as well as limit and target values were established for this pollutant. On the basis of PM2.5 measurements in urban background locations, an average exposure index (AEI) is calculated for the reference year 2010, based on the mean concentration in 2008, 2009 and 2010. This exposure index determines the reduction percentage which a member state is required to achieve by 2020. The new Directive also provides for additional flexibility for deducting natural sources when assessing the quality objectives and makes provisions for postponing the deadline for attaining the limit values for NO2, PM10 and benzene. Where particulate matter exceedances are due, fully or partially, to natural sources, the relevant portion may be excluded. The contribution from winter-sanding and -salting may also be subtracted.
Also the criteria for aggregating data and calculating statistical parameters have largely been taken over from the old Framework Directives. One exception is the calculation of 24-hour values, for which, according to the new Directive, at least 75% of the hourly averages must be available. The Directive also makes provisions that in zones or agglomerations where it is difficult to meet the defined limit values by the target date, the attainment deadline for the limit values may be postponed by a specified period (until 2011 for PM10 and until 2015 for benzene and NO2). For this, a detailed plan must be drawn up showing that attainment by the end of the revised period is guaranteed. This plan must be approved by the European Commission. In 2009 the request for postponing compliance with the 50 μg/m³ daily limit value for PM10 in various zones in Flanders, Brussels and Wallonia was not approved. Like many other European member states (22 of the 27), Flanders and Brussels failed to meet the European annual limit value of 40 μg/m³ for nitrogen oxide (NO2) in 2010. In early 2012 Flanders drew up an Air Quality Plan featuring a package of measures to meet the European limit value by 2015. For its zones in exceedance – the Antwerp agglomeration and the Port of Antwerp - the Flemish Region was granted permission by the European Commission to postpone compliance with the annual mean NO2 limit value until 2015. Until that date, the limit value in those zones is 60 μg/m³. No postponement was granted to the Brussels-Capital Region. An overview of the requests for postponement and the related decisions of the European Commission can be found via the following website link: http://ec.europa.eu/environment/air/quality/legislation/time_extensions.htm
The air quality guideline values of the WHO (World Health Organisation) are more stringent than the limit and target values imposed by the European Union. The purpose of the EU limit and target values is to identify how the best possible air quality offering maximum protection to the population in all EU-27 member states can be achieved in the most cost-effective way. To achieve these objectives, Europe takes into account not only health reasons but also economic feasibility. The guideline values proposed by the WHO are therefore an acceptable and feasible objective to minimise health effects within local capabilities and constraints and public health priorities. For particulate matter, for example, the WHO did not establish a lower limit below which no harmful health effects occur.
Table 1 gives an overview of the various limit and target values for each pollutant, and the dates by which they are to be met. Table 2 lists the information and alert thresholds at which the population must be informed or alerted. Table 3 gives the more stringent air quality guideline values as proposed by the WHO
Table 1: Overview of European limit and target values for the various pollutants according to EU Directive 2008/50/EC
Table 2: Overview of average hourly information and alert thresholds according to EU Directive 2008/50/EC
Table 3: Overview of air quality guideline values of the World Health Organisation