e-Digest Statistics about: Air Quality
Concentrations of Nitrogen dioxide (NO2) and nitrogen oxides (NOx)
Nitrogen oxides are acid gases and ozone pre-cursors and can affect human health and vegetation. Nitrogen dioxide is thought to have both acute and chronic effects on airways and lung function, particularly in people with asthma. The Air Quality Expert Group produced a detailed new study Nitrogen Dioxide in the UK in 2004. [43]
Table 7 shows NO2 concentrations and exceedences against the Air Quality Strategy, UK and EC criteria for automatic monitoring sites in 2006. The UK Air Quality Strategy health objective, that the 1 hour mean should not exceed 200µg/m3 more than 18 times a year by 2005 was not met at two sites: London Marylebone Road kerbside site and the Camden Kerbside site. The health objective that the annual mean should not exceed 40µg/m3 to be met by 2005 was achieved by 77 per cent of the sites in 2006. Figure 3 and Figure 4 show trends in exceedences at urban sites of the objective levels for the 1-hour and health-based annual mean respectively. There were 6 sites where hourly concentrations reached 'moderate' levels in 2006. None of the sites exceeded the EC Alert Threshold on any one day.
Further Information:
- Data Tables:
- 7 Concentrations of nitrogen dioxide (NO2) and exceedances against the Air Quality Strategy, UK and EC criteria at national monitoring network sites: 2006 XLS
- Fig 3 Nitrogen dioxide 1 hour mean: Number of periods exceeding 200µg/m³ compared with health objective for 2005: 1987-2005 (data for figure) XLS
- Fig 4 Nitrogen dioxide annual mean: Comparison with health objective for 2005: 1987-2005 (data for figure) XLS
- References, further reading and links to other resources:
- [43] Nitrogen Dioxide in the United Kingdom. Defra, (2004) Report.
- Internet Links:
- UK National Atmospheric Emissions Inventory (NAEI)
- National Air Quality Information Archive
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Page last modified: 3 March 2008
Page published: 30 March 2006