Local authorities are now under a duty to review and assess air quality in their areas. The main objective is to identify zones where pollution levels are likely to exceed statutory air quality objectives by 2005 (ENDS Report 274, p 40 ).
Monitoring activities to inform this process should be based on a phased approach, the DETR says. If necessary, an initial screening process should be followed by a more detailed survey using simple monitoring and modelling techniques. If breaches of the objectives are still likely, a more detailed assessment should be undertaken.
The guidance sets out reference methods, monitoring strategies, and quality assurance and control procedures for each of the seven prescribed pollutants.
Another of the guidance documents deals with the compilation of local emissions inventories, which are of particular importance in identifying pollution hotspots caused by heavy traffic or industrial point sources.
Several local authorities involved in producing trial inventories have run into great difficulties - not least in obtaining meaningful data for smaller industrial processes. Moreover, inventories will need to project emissions in 2005. The DETR accepts that "this is, potentially, a difficult and complex area" - particularly with industrial sources.