Conclusions of Phase 1 Review and Assessment
The Council’s Stage 1 Review and Assessment did not identify any sources with potentially significant emissions of benzene and further assessment of benzene concentrations was therefore not required at Stage 2.
Estimated and Monitored Data
Estimated annual mean background benzene concentrations have been compiled and mapped for the UK on a 1 km x 1 km basis5. Details of background concentrations in the West Berkshire region during 2001, 2003 and 2010 have been collated and are detailed in Table 5.1 below
The maximum estimated annual mean concentrations of 0.56 µg/m3 and 0.43 µg/m3 are below the relevant AQOs for 2003 and 2010, respectively.
Estimated annual mean background concentrations - benzene (µg/m3)
Road traffic data have been provided by WBC and are detailed in Appendix A. Guidance specifies that where AADT flows are not expected to exceed 80,000 or 140,000 vehicles per day in 2010 (single carriageway and motorway, respectively) and annual mean concentrations are expected to be below 2 µg/m3, a screening assessment will not be required.
No roads within the region have been identified with predicted 2010 AADT flows exceeding 80,000 vehicles or 140,000 vehicles. Estimated background data (Table 5.1) indicate that the maximum annual mean concentration in 2010 will be 0.43 µg/m3. It is therefore considered that further assessment of road transport sources for benzene is not required.
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