Key Scottish Environment Statistics 2012

Air Quality - Footnotes

1) All values displayed in the chart are at or above the 50% data capture rate. If the data capture rate for any site is below 50% then the data will not be included in the chart. Where this occurs, information will be provided as appropriate in further footnotes. When assessing whether sites met the Air Quality Strategy objectives, only those sites with 75% data capture rate are included.

2) In 2003, the data capture rate for Edinburgh Centre was low (under 50%). The 2003 data for Edinburgh are therefore unreliable and will not be included in any charts or tables. The 2003 figure for Edinburgh is: PM10 = 25. The site stopped recording on the 13th of October and the monitor was then relocated to an urban background site at Edinburgh St Leonards, which started recording on 24 November 2003.

3) In 2010, the data capture rate for Glasgow Centre was low (under 50%). The 2010 data for Glasgow are therefore unreliable and will not be included in any charts or tables. The 2010 figure for Glasgow is: PM₁₀ = 23.

4) MacCarthy, J., Li, Y., Murrells, T.P., Okamura, S., Passant, N., Sneddon, S. Martinez, C., Thomas, J., Thistlethwaite, G. & Misselbrook, T. (2011). Air Quality Pollutant Inventories for England, Scotland, Wales and Northern Ireland: 1990-2009.

5) Department for Environment, Food and Rural Affairs, Scottish Executive, Welsh Assembly Government & DOE Northern Ireland (2007). The Air Quality Strategy for England, Scotland, Wales and Northern Ireland Volume 1.

6) In 2011, PM₁₀ concentration was measured at 75 automatic monitoring sites in Scotland. Of these sites, 53 none exceeded the 40 µg/m³ UK AQS - data for these sites are available on the Scottish Air Quality Database.

7) In 2003, the data capture rate for Edinburgh Centre was low (under 75%). The 2003 data for Edinburgh Centre are therefore unreliable and will not be included in any charts or tables. The 2003 figure for Edinburgh is: NO₂ = 50. The site stopped recording on the 13^th of October and the monitor was then relocated to an urban background site at Edinburgh St Leonard, which started recording on 24 November 2003.

8) In 2003, the data capture rate for Glasgow Centre was low (under 50%). The 2003 data for Glasgow Centre are therefore unreliable and will not be included in any charts or tables. The 2003 figure for Glasgow is: NO₂ = 39.

9) In 2011, concentrations of nitrogen oxides are measured at 71 automatic monitoring sites in Scotland. Of these sites, 58 had a capture rate of at least 75% - data for these sites can be found on the Scottish Air Quality Database.

10) In 2010, ozone concentrations were measured at 11 sites, all of which had a data capture rate of at least 75%. Data for these sites are available on the Scottish Air Quality Database.

11) Large combustion plants have a rated thermal output of over 50 megawatts.

12) Department for Environment, Food and Rural Affairs - Environment Statistics website.

13) Scottish coal contains a greater proportion of sulphur than many other sources of coal, which results in the higher volumes of SO₂ being produced during electricity production. Scottish Power Longannet Power Station.

14) 3-year average deposition is used to reduce substantial year to year variability. Deposition data for 1995-97 to 1999-01 are based on the same methodology. Changes have been made to the methods for estimating deposition subsequently: (i) nitric acid deposition has been included in data from 2001-03 onwards; (ii) aerosol deposition of NH4, NO3, SO4 has been included in data from 2002-04 onwards. Therefore deposition for earlier years may be underestimated and hence the actual reductions may be larger than shown here.

15) Hall, J. et al. (2008). Status of UK Critical Loads and Exceedances. UK National Focal Centre for Critical Loads Mapping & Modelling, Centre for Ecology and Hydrology.

16) All nutrient nitrogen critical load exceedance values were reviewed and updated in 2011. Hall, J. et al. (2011). UK Status Report July 2011: Update to Empirical Critical Loads of Nitrogen. UK National Focal Centre for Critical Loads Mapping & Modelling, Centre for Ecology and Hydrology.