In September of each year, the UK submits a report to the European Commission on compliance with EU limit values for all pollutants in Directive 2008/50/EC and Directive 2004/107/EC. This report is prepared on the basis of monitoring data gathered during the previous year (which is ratified on a quarterly basis) and modelled data prepared following the ratification of the last quarter's data. Ratified monitoring data for the full year 2009 is not available until April 2010.
Provisional monitoring data for 2009 indicates that the NO2 (nitrogen dioxide) limit values were likely to have been exceeded in the following towns and cities: Bristol, Cambridge, Sandy, Glasgow, London, Manchester, Bury, Aberdeen, Oxford, Bath, Birmingham and Leeds. It should be noted that data from these monitored sites alone might underestimate the number of actual exceedences of the NO2 limit value. A full assessment of exceedences on the basis of both modelled and monitored data will be reported to the European Commission in September 2010.