footnotes
Air Quality
1) PM 10 concentrations are measured at automatic monitoring sites: Aberdeen (an urban background site), Edinburgh St Leonards (an urban background site), Grangemouth (an urban industrial site), Glasgow Centre (an urban centre site) and Glasgow City Chambers (an urban background site). PM 10 is also measured by non-automatic gravimetric samplers at two further sites: Dumfries and Inverness.
2) In 2003 the data capture rate for Edinburgh Centre was low (under 50%). The 2003 data for Edinburgh is therefore unreliable and will not be included in any charts or tables. The 2003 results for Edinburgh are: PM 10: mean=25, days exceeding=5; NO 2: mean=50, days exceeding=0; CO: 8-hour mean=0.9, annual mean=0.3; O 3: days exceeded=0, annual mean=42; SO 2: 15-min mean=1, winter mean (October 2002 to March 2003)=9. 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) Department for Environment, Food and Rural Affairs Environmental Statistics website: http://statistics.defra.gov.uk/esg/
4) Department for Environment, Food and Rural Affairs, Scottish Executive, Welsh Assembly Government & DOE Northern Ireland (2003). The Air Quality Strategy for England, Scotland, Wales and Northern Ireland: Addendum.
5) Concentrations of nitrogen oxides are measured at eight automatic monitoring sites: Aberdeen, Dumfries, Edinburgh, Grangemouth, Inverness and three sites in Glasgow.
6) In 2003 the data capture rate for nitrogen dioxide concentrations in Glasgow Centre was low (under 50%), it will therefore be excluded from the table and chart. The 2003 results for Glasgow are: annual mean=39, days exceeding=0. The data capture for sulphur dioxide during the period October 2002 to March 2003 was also low. The winter mean for 2002 was 16.
7) Carbon monoxide concentrations are measured at seven automatic monitoring sites: Aberdeen, Dumfries, Edinburgh, Inverness and three sites in Glasgow.
8) Ozone concentrations are measured at five sites: Eskdalemuir (a rural site), Strath Vaich (a remote site), Bush Estate (a rural site), Edinburgh St Leonards and Glasgow.
9) Objective not currently included in the Air Quality Regulations because of the transboundary nature of ozone.
10) Measurements are made using the non-automatic Net Acidity method, expressed as SO 2 equivalent. In recent years, as ambient levels of SO 2 have fallen this method has increasingly tended to overestimate actual SO 2.
11) Means have been calculated over the 'pollution year' from April to March. For example, the 2002 figures have been calculated from the beginning of April 2002 to the end of March 2003.
12) No 1965, 2002 or 2003 figures for Edinburgh.
13) Sulphur dioxide concentrations are measured at four automatic monitoring sites: Aberdeen, Edinburgh (Edinburgh Centre ceased operation in 2003), Glasgow and Grangemouth.
14) Large combustion plants have a rated thermal output of over 50 megawatts.
15) One site's reported emissions had not been signed off at the time of publication. This may affect the 2005 'Other industry' figures.
16) Smith, et al. (unpublished) Sulphur deposition in Scotland, in Report for the Scottish Office under EVF/1/13 CRU 95/96.