Volatile C<SUB>1</SUB> and C<SUB>2</SUB> chlorinated hydrocarbons and their oxidative degradation products are possible contributors to forest decline in Europe and north America. These species originate from both natural and anthropogenic sources, the latter including use as solvents and degreasers within the chemical, dry-cleaning and nuclear industries. Concentrations have been reported in central European forest air, soil and foliage, but no measurements have been made in the UK. This study presents the temporal and spatial distribution of 1,1,1-trichloroethane (C<SUB>2</SUB>H<SUB>3</SUB>Cl<SUB>3</SUB>), tetrachloromethane (CCl<SUB>4</SUB>), trichloroethene (C<SUB>2</SUB>HCl<SUB>3</SUB>) and tetrachloroethene (C<SUB>2</SUB>Cl<SUB>4</SUB>) in air and foliage of three northern UK forests over a 15 month period. Potential sources were identified as petrochemical industry at Grangemouth (Central Region, Scotland) and the nuclear reprocessing complex at BNFL plc. Sellafield (Cumbria, England). A 'clean' site (Grampian, Scotland) was included for comparison. The tree species monitored was <I>Pinus sylvestris</I> (L.). Air measurements were made using novel passive diffusion samplers containing an extract of <I>Pinus sylvestris</I> (L.) wax exposed to the atmosphere for approximately one month. Analysis of the tubes and composite needle samples used solvent extraction and quantitative capillary gas chromatography with electron capture detection. Complementary GC-MSMS was used qualitatively. The needle concentrations found were similar to those of central Europe, and were log-normally distributed. Geometric mean concentrations (ng/g dry weight) were C<SUB>2</SUB>H<SUB>3</SUB>Cl<SUB>3</SUB> 20; CCl<SUB>4</SUB> 5; C<SUB>2</SUB>HCl<SUB>3</SUB> 130; C<SUB>2</SUB>Cl<SUB>4</SUB> 30. There was no statistically significant difference at the 95% level between median concentrations at the three sites, or between the 1992 and 1993 needle year classes. The geometric standard deviation of 2-3 was typical of other gaseous pollutants, and the vertical profile through the canopy at Devilla forest suggested an atmospheric source.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:642075 |
| Date | January 1995 |
| Creators | Brown, Ruth Helen Alison |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13035 |
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