Nitrogen Dioxide May be Underestimated in `Forgotten Towns`

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 old houses sit very close to busy through-roads. The Institution warns that effects such as this could make the scale of the problem far greater than Defra is currently planning for.