Daily 24 hour (00:00 - 24:00) co-located PM<sub>10</sub>, PM<sub>2.5</sub>, and Black Smoke samples were collected for a period of 1 year (September 1999 to September 2000) at an urban background site in central Edinburgh, and monthly at a rural site 30 km SSW of Edinburgh. Sample mass concentrations were determined gravimetrically, and the daily water and acid (2.8:1 HCl/HNO<sub>3</sub> v/v) extractable metal concentrations of Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb, determined by ICP-MS. Median urban background PM<sub>2.5</sub> water soluble metal concentrations ranged from 0.05 ng m<sup>-3</sup> for Ti to 5.06 ng m<sup>-3</sup> for Pb, and in PM<sub>10</sub> from 0.18 ng m<sup>-3</sup> for Ti to 11.74 ng m<sup>-3</sup> for Fe. Median PM<sub>2.5</sub> total (water + acid) extractable metal concentrations ranged from 0.30 ng m<sup>-3</sup> for As to 27.60 ng m<sup>-3</sup> for Fe, and in PM<sub>10</sub> from 0.37 ng m<sup>-3</sup> for As to 183.44 ng m<sup>-3</sup> for Fe. Fe concentrations represented c. 80% of the total (water + acid) metal exposure from metals analysed in the PM<sub>10</sub> fraction, although Pb and Zn constituted over 50% of the water soluble metal exposure in PM<sub>2.5</sub>. Significant seasonal differnces (P <0.05) were observed in the metal concentrations, which varied with metal, coupled with an overall shift towards a higher proportion of acid extractable/lower proportion of water soluble metal in the winter months. Seasonal differences were also present in the urban : rural ratio, which ranged from ~3 in the spring to up to ~10 in winter. Urban background metal concentrations were also found in general to correlate more strongly with BS ‘mass concentration equivalent’ than with PM<sub>10</sub> or PM<sub>2.5</sub> mass concentrations. Hierarchical clustering of 5 day air mass back trajectories demonstrated that there were significant differences (P <0.05) in metal concentrations (ng m<sup>-3</sup>) and metal ‘enrichment factors’ (EFs, ng μg<sup>-1</sup> particulate matter) depending on air mass source/direction.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:652413 |
| Date | January 2002 |
| Creators | Hibbs, Leon R. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12077 |
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