Summary

Under Council Directive 96/62/EC on Air Quality Assessment and Management, Member States are required to assess air quality throughout their territory. The requirements for those assessments depend on the nature of the area and the levels of air pollution, in relation to limit values as defined in Daughter Directives. In Article 5 it is stated that Member States which do not have representative measurements of the levels of pollutants for all zones and agglomerations shall undertake series of representative measurements, surveys or assessments in order to have the data available in time for implementation of the Daughter Directives.

In this report, guidance is provided on undertaking an assessment of air pollution levels as required by Article 5. It is recommended to use information from three main assessment methods: measurements, emission inventories, and modelling. Information on measurement methods concentrates on indicative measurements, for the case where data from representative monitoring are not available or incomplete. For emissions, information is provided on the CORINAIR methodology; some information is also provided for some pollutants currently not covered in CORINAIR, such as PM10. Guidance is also provided on selecting and using models for the calculation of air pollution levels from the emissions, and comparing the results with measurements.

It is strongly recommended to estimate total uncertainty of the results for each assessment method, and for the result as a whole.

This guidance focuses on those pollutants for which Daughter Directives have been proposed in 1997, viz. SO₂, NO₂/NO, particulate matter (PM10) and lead.

It is recommended that the results obtained from these assessment methods be presented as maps, where the spatial extent of an area exceeding limit values, or requiring a certain assessment methodology, can be easily seen. The total uncertainty in the result of the assessment may be compared to the margins taken into consideration to account for the inter-annual variation of the air pollution levels.

The current report will need updating and supplementing in the coming years, as experience in the Member States in this area develops further. Clearly further guidance will be needed for the preparation of air quality assessments under Article 6 of the Directive, for example, on the optimised and representative siting of measuring stations.