8 Projections for sites expected to exceed the EU Stage 1 limit value

Additional PM₁₀ projections have been calculated for the five monitoring sites for which the 1997 receptor modelling indicated that concentrations may exceed the EU stage 1 24-hour limit value in 2004 for the business as usual scenario. Four of these sites are roadside: Bury Roadside, Glasgow Roadside, Camden Roadside and Marylebone Road and one is industrial: Port Talbot.

The scenarios examined were:

• Scenario a: Business as usual.
  
• Scenario h: A 30% reduction in traffic emissions including buses, lorries etc. Business as usual for secondary particle emissions.
  
• Scenario i: A 30% reduction in car emissions. Business as usual for secondary particle emissions.
  
• Scenario j: Traffic emissions reduced by 50% and a reduction of 50% of the business as usual levels for secondary particles. (The same scenario as in Table 4.4.)
  The impact of scenarios h and i on roadside NO2 concentrations in the UK have been examined by Stedman, Bush and King (1998) and are included here to show the impact of these emission reductions on PM₁₀ concentrations. It should be noted that no specific policy measures have been identified which could achieve the reductions implied in scenario j.
  
  Port Talbot forecasts were made as described for industrial sites. The other sites were treated as previously described for roadside sites. The projections for the different scenarios are listed in Table 8.1.
  
  Bury Roadside achieves the EU Stage 1 objective under each of the new scenarios. Glasgow and Camden sites achieve the objective under scenarios h and j, whilst both London Marylebone Road and Port Talbot exceed the objective under even the most optimistic scenario.