Fjölrit RALA - 15.06.2004, Síða 133

were extracted using yHPCD (a cyclodextrin molecule) and XAD (a polymeric absorbent)
(Puglisi et al., 2003; Semple et al., 2003). In addition to this the soils were also amended with
a range of concentrations of dichlorophenol and pentachlorophenol (CPs). A range of semi-
solvent extractions were used to elucidate the bioavailable fraction. Analysis was carried out
for the PAHs and CPs using HPLC and bioluminescent-based biosensors (Tiensing et al.
2002).
Results and discussion
The levels of POPs in the areas studied were in most cases just above the detection Umits.
Elevated levels that were detected were a consequence of land-use and there was little
evidence to suggest that the accumulation of POPs is as significant as proposed for the High
Arctic. Andosols and Histosols are likely to actively sequester atmospherically derived POPs
rendering them unavailable. Seasonal deposition may be of more concem and merits further
focused investigation.
Andosols caused considerable challenges in terms of analysis and the traditional techniques
required a level of modification to best suit the trace detection required. Nevertheless,
Andosol-specific techniques have been developed yielding highly satisfactory results.
When Andsosols were amended with pollutant doses, as expected, they sequestered a
significant proportion of the contaminants. For PAHs, the hydrophobic nature of the
compounds rendered them sparingly soluble when extracted by non-exhaustive techniques. In
the case of the CPs, they were also found to become tightly bound to the organic fractions
within the Andosols. Comparative studies with Scottish soils suggest that Andosols have
binding affinity values perhaps several orders of magnitude greater. Hence, even if POPs
were being deposited in this environment, the sequestration efficiency of the soils may render
their environmental impact to be significantly less than that associated with skeletal soils.
Conclusions
POPs are ubiquitous in the environment even though they have little recorded use in Iceland.
Point source contaminants are probably a more significant environmental threat, but are easier
to monitor. Snowfall and certain weather conditions may explain incidents of elevated diffuse
contamination. Andosols are however resilient and are able to render these pollutants
biologically unavailable.
References
Dawson, J.J.C., Maciel, H., Semple, K.T. and Paton, G.I. 2003. Analysis of organic pollutants
in environmental samples in Methods of Soil Analysis (ed. Cresser, M.S and Smith K.)
Marcel Dekker, New York.
Puglisi E, Patterson CJ, Paton GI., 2003. Non-exhaustive extraction techniques (NEETs) for
bioavailability assessment of organic hydrophobic compounds in soils. Agronomie 23, 755-
756.
Semple KT, Morriss AWJ, Paton GI., 2003. Bioavailability of hydrophobic organic
contaminants in soils: fundamental concepts and techniques for analysis. European Joumal
of Soil Science 54, 809-818.
Strachan, G., Capel,S., Maciel, H., Porter, A.J.R. and Paton, G.I.2002 Application of cellular
and immuno biosensor techniques to assess herbicide toxicity in soils. European Joumal of
Soil Science 53, 37-44.
Tiensing T, Strachan N, Paton G.I. 2002. Evaluation of interactive toxicity of chlorophenols
in water and soil using lux-marked biosensors. Joumal of Environmental Monitoring 4, 482-
289.
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