Nitrogen Dioxide
(asked on 7th November 2017) - View Source
Question to the Department for Environment, Food and Rural Affairs:
To ask Her Majesty's Government which places in the UK have had the highest levels of nitrogen dioxide exceedance of agreed EU limits in each year since 1997 for which records are held; and how many times the World Health Organisation's guideline for PM 2.5 has been exceeded.
Between 1997 and 2000 inclusive, the limit value for hourly mean concentrations of nitrogen dioxide was 200 µg/m3 and could only be exceeded for two percent of the calendar year for any monitoring site. This limit was determined by the Council Directive on air quality standards for nitrogen dioxide (85/203/EEC). All air quality monitoring sites for nitrogen dioxide were compliant with the limit value between 1997 and 2000.
Under the First Daughter Directive (1999/30/EC) and Air Quality Directive (2008/50/EC), the limit value for hourly mean nitrogen dioxide concentrations is 200 µg/m3 and Member States are allowed to exceed this limit for a maximum of 18 hours per calendar year. The monitoring sites with the greatest number of hours in exceedance of this limit by year are displayed in the table below (site measurements are available on the UK-AIR website):
Year | Assessment area | Monitoring site | Hours with NO2 concentration > 200 µgm-3 |
2001 | Greater London Urban Area | London Marylebone Road | 60 |
2002 | Glasgow Urban Area | Glasgow Kerbside | 38 |
2003 | Greater London Urban Area | London Marylebone Road | 471 |
2004 | Greater London Urban Area | London Marylebone Road | 542 |
2005 | Greater London Urban Area | London Marylebone Road | 853 |
2006 | Greater London Urban Area | London Marylebone Road | 686 |
2007 | Greater London Urban Area | London Marylebone Road | 458 |
2008 | Greater London Urban Area | London Marylebone Road | 822 |
2009 | Greater London Urban Area | London Marylebone Road | 486 |
2010 | Greater London Urban Area | London Marylebone Road | 539 |
2011 | Greater London Urban Area | London Marylebone Road | 229 |
2012 | Greater London Urban Area | London Marylebone Road | 132 |
2013 | Greater London Urban Area | London Marylebone Road | 60 |
2014 | Greater London Urban Area | London Marylebone Road | 60 |
2015 | South Wales | Hafod-yr-ynys Roadside | 108 |
2016 | South Wales | Hafod-yr-ynys Roadside | 126 |
The limit value for annual mean nitrogen dioxide concentrations is 40 µg/m3. Assessment is made using a mixture of monitoring site data, modelling of major roadside concentrations in urban areas and modelling of background concentrations. The maximum annual mean concentration of nitrogen dioxide and its location in the UK are displayed in the table below (monitoring and modelling data can be found on the UK-AIR website):
Year | Assessment area | Location | Annual mean NO2 concentration (µg/m3) |
2001 | Central Scotland | Modelled background location east of Glasgow (close to A73 and B803) | 95 |
2002 | Greater London Urban Area | A3211 (between City of London boundary and A201 Blackfriars Bridge junction) | 87 |
2003 | Greater London Urban Area | A501 (between Marylebone High St and A4201 junctions) | 109 |
2004 | Greater London Urban Area | A40 (between Portman St and Duke St junctions) | 113 |
2005 | Greater London Urban Area | A40 (between Portman St and Duke St junctions) | 184 |
2006 | Greater London Urban Area | A40 (between Portman St and Duke St junctions) | 168 |
2007 | Greater London Urban Area | A40 (between Marble Arch and Portman St junctions) | 155 |
2008 | Greater London Urban Area | A40 (between Marble Arch and Portman St junctions) | 182 |
2009 | Greater London Urban Area | A40 (between Portman St and Duke St junctions) | 163 |
2010 | Greater London Urban Area | A40 (between Portman St and Duke St junctions) | 170 |
2011 | Greater London Urban Area | A40 (between Portman St and Duke St junctions) | 136 |
2012 | Greater London Urban Area | A302 (between A3217 and A4 junctions) | 152 |
2013 | Greater London Urban Area | A4 (between A315/A3216 and Hyde Park Corner junctions) | 126 |
2014 | Greater London Urban Area | A40 (between A4206 and A5/A501 junctions) | 119 |
2015 | Greater London Urban Area | A3211 (between A100 junction and Tower Hamlets boundary) | 115 |
2016 | Greater London Urban Area | A3211 (between Arthur St and Fish St Hill junctions) | 102 |
The UK is compliant with the Air Quality Directive and its predecessors regarding concentrations of PM2.5. All areas of the UK had maximum annual mean concentrations less than 20 µg/m3 in 2016 (the limit value set by the European Union); but in every year some areas across the UK have exceed the WHO guideline of 10 µg/m3 annual mean and a 24-hour mean of 25 µg/m3. Weighting the concentrations according to where the population lives gives annual mean concentrations which are less than the WHO guideline (9 µg/m3 in 2016).