Introduction

The EU Limits for nitrogen dioxide (NO2) must be attained by 2010 unless the UK Government applies to the European Commission for a time extension. An extension will only be allowed if the Government can provide a robust case, demonstrating that there is an action plan in place that will ensure that limit values will be met.

The main cause of poor air quality is emissions from road traffic and currently there are NO2 exceedances along 3,500km of busy roads across the UK. Work undertaken for Defra by AEAT suggests that in the absence of further action, 849km of roads in the UK could fail the annual mean objective. Currently 208 local authorities have declared Air Quality Management Areas for one of the objectives, from London Boroughs to small market towns in rural areas. However, CIWEM fears that current monitoring of NO2 could be failing to pick up localised exceedances which occur as a result of 'town canyon' effects that commonly occur in small, non-bypassed market towns where buildings sit very close to busy through-roads. It warns that effects such as this could make the scale of the problem far greater than Defra is currently planning for.

This issue will be the main focus of discussion at CIWEM's forthcoming policy workshop on compliance with EU Limit Values for Nitrogen Dioxide, to be held in London on 24th September.

CIWEM Executive Director, Nick Reeves, said: "We are concerned that there might be rather too much focus on the obvious targets when it comes to tackling NO2 - busy roads in large towns and cities. But there could be a whole legion of forgotten towns - those historic towns in more rural areas where buildings sit close to the main road and prevent the pollution from dispersing. Here you get quite significant spikes in NO2 pollution which, although very localised, seem to occur in quite typical locations, and there are many such towns in the UK. For their residents, this is a serious issue."

Aims and key questions

The seminar aims to explore the extent of the anticipated exceedances of the NO2 limit values in 2010 and the measures required to bring the UK into compliance by 2015. The workshop is timed to feed into Defra’s consultation on the time extension for achieving the NO2 limit values.

The seminar will raise a number of timely questions which we hope the debate will help further including:

• By focusing on national data and largely ignoring Local Air Quality Management data, as in the development of the 2007 Air Quality Strategy, is Defra underestimating the problem? For example, will small market towns, where high levels of NO2 have been measured, be overlooked, because they don’t show on the national modelling?
• What are the measures being considered by Defra?
• What is the real world evidence of the efficacy of the measures being considered?
  
• Are there further measures that should be considered?

Defra are likely to be launching a consultation on this topic in the autumn. The debate is further elaborated in the CIWEM Policy Statement which can be downloaded from the conference webpage www.coastms.co.uk or CIWEM website www.ciwem.org/policy/policies