High Level Summary of Statistics Trend Last update: Thursday, May 31, 2012
Ground Level Ozone Concentration
Ozone in the stratosphere forms a layer that protects the earth against harmful ultra-violet radiation, but tropospheric (ground level) ozone is a damaging oxidant. Exposure to high ozone concentrations can cause respiratory damage, and affects vegetation by damaging leaves and reducing yields.
Ozone is formed by a slow, complicated series of reactions from other pollutants that may be blown over from Europe. The most important man-made precursors are nitrogen oxides and volatile organic compounds produced by road transport, industrial processes and solvent use. Ozone concentrations tend to be lower in urban areas where it is converted to nitrogen dioxide by reacting with nitrogen oxides.
The Air Quality Strategy 1 objective for ground level ozone (to be met by 2005) states that the maximum daily concentration (measured as an 8-hour running mean) of 100µg/m3 should not be exceeded more than 10 times per year. In 2011, this objective was met at 8 of the 11 sites.2 The sites that failed were Straith Vaich, Bush Estate and Lerwick. Since 1990 there has been relatively little variation in annual average concentrations.
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Source: Scotland Air Quality Data and Statistics Database
Note (1): Department for Environment, Food and Rural Affairs, Scottish Executive, Welsh Assembly Government and DOE Northern Ireland. The Air Quality Strategy for England, Scotland, Wales and Northern Ireland.
(2): 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.