Earthworms and in vitro physiologically-based extraction tests: complementary tools for a holistic approach towards understanding risk at arsenic-contaminated sites
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The relationship of the total arsenic content of a soil and its bioaccumulation by earthworms (Lumbricus rubellus and Dendrodrilus rubidus) to the arsenic fraction bioaccessible to humans, measured using an in vitro physiologically-based extraction test (PBET), was investigated. Soil and earthworm samples were collected at 24 sites at the former arsenic mine at the Devon Great Consols (DGC) in southwest England (UK), along with an uncontaminated site in Nottingham, UK, for comparison. Analysis of soil and earthworm total arsenic via inductively coupled plasma mass spectrometry (ICP-MS) was performed following a mixed acid digestion. Arsenic concentrations in the soil were elevated (204–9,025 mg kg−1) at DGC. The arsenic bioaccumulation factor (BAF) for both earthworm species was found to correlate positively with the human bioaccessible fraction (HBF), although the correlation was only significant (P ≤ 0.05) for L. rubellus. The potential use of both in vitro PBETs and earthworms as complementary tools is explored as a holistic and multidisciplinary approach towards understanding risk at contaminated sites. Arsenic resistant earthworm species such as the L. rubellus populations at DGC are presented as a valuable tool for understanding risk at highly contaminated sites.
KeywordsArsenic Bioaccessibility Bioaccumulation Exposure Risk
The authors wish to thank the British Geological Survey University Funding Initiative (BUFI) for funding this research as part of a PhD studentship. We are also grateful to Joanna Wragg of the British Geological Survey for reviewing the manuscript and the late Tim Brewer for his guidance early on in the studentship. We would also like to thank the Tavistock estate for granting permission to access the Devon Great Consols site.
- BARGE (the Bioaccessibility Research Group of Europe). (2008). Retrieved on 22 February 2008, from http://www.bgs.ac.uk/barge/home.html.
- Blank, S., Seiter, C., & Bruce, P. (2001). Resampling stats in excel version 2. Arlington.Google Scholar
- Cave, M. R., Wragg, J., Palumbo, B., & Klinck, B. A. (2002). Measurement of the bioaccessibility of arsenic in UK soils. Environment Agency R&D Technical Report, P5-062/TR002.Google Scholar
- Defra. (2002). The contaminated land exposure assessment model (CLEA): Technical basis and algorithms CLR10. Environment Agency.Google Scholar
- Efron, B., & Tibshirani, R. J. (1993). An introduction to the bootstrap. Chapman & Hall.Google Scholar
- Elteren, J., Zdenka, S., Iztok, A., & Hylke-Jan, G. (2005). An interdisciplinary physical-chemical approach for characterization of arsenic in a calciner residue dump in Cornwall (UK). Environmental Pollution, 139, 477–488.Google Scholar
- Fergusen, C., Nathanail, P., McCaffrey, C., Earl, N., Foster, N., Gillet, A., & Ogden, R. (2003). Method for deriving site-specific human health assessment criteria for contaminants in soil. Retrieved on 22 February 2000, from Scottish and Northern Ireland Forum for Environmental Research website. http://www.sniffer.org.uk/results.asp.
- Green, K. A., Chenery, S. R., Barlow, T. S., Taylor, H., & Cook, J. M. (2006). A high productivity sample digestion and analysis methodology for the determination of major and trace elements by ICP, poster presentation. In 13th Biennial National Atomic Spectroscopy Symposium, Glasgow, UK.Google Scholar
- Hamilton, E. I. (2000). Environmental variables in a holistic evaluation of land contaminated by historic mine wastes: A study of multi-element mine wastes in West Devon, England using arsenic as an element of potential concern to human health. Science of the Total Environment, 249, 171–221.CrossRefGoogle Scholar
- Kavanagh, P. J., Farago, M. E., Thornton, I., & Braman, R. S. (1997). Bioavailability of arsenic in soil and mine wastes of the Tamar valley, SW England. Chemical Speciation and Bioavailability, 9, 77–81.Google Scholar
- Klinck, B. A., Palumbo, B., Cave, M. R., & Wragg, J. (2002). Arsenic dispersal and bioaccessibility in mine contaminated soils: A case study from an abandoned arsenic mine in Devon, UK. British Geological Survey, Research Report RR/04/003.Google Scholar
- Palumbo-Roe, B., & Klinck, B. (2007). Bioaccessibility of arsenic in mine waste-contaminated soils: A case study from an abandoned arsenic mine in SW England (UK). Journal of Environmental Science and Health—Part A Toxic/Hazardous Substances and Environmental Engineering, 42, 1251–1261.Google Scholar
- Royal Society of Chemistry: A simple fitness-for-purpose control chart based on duplicate results obtained from routine test materials: Analytical Methods Committee Technical brief number 9. (2002). Retrieved on 22 February 2008 from http://www.rsc.org/images/brief9_tcm18-25951.pdf.
- Van Vliet, P. C. J., Didden, W. A. M., Van der Zee, S. E. A. T. M., & Peijnenburg, W. J. G. M. (2006). Accumulation of heavy metals by enchytraeids and earthworms in a floodplain. European Journal of Soil Biology, 42, S117–S126.Google Scholar
- Wragg, J., Cave, M., & Nathanail, P. (2007). A study of the relationship between arsenic bioaccessibility and its solid-phase distribution in soils from Wellingborough, UK. Journal of Environmental Science and Health—Part A Toxic/Hazardous Substances and Environmental Engineering, 42, 1303–1315.Google Scholar
- Worm Watch Canada: Key to reproductively mature earthworms. (2008). Retrieved on 22 February 2008 from http://www.naturewatch.ca/english/wormwatch/resources/key/taxonomic.html.