Ecotoxicity of long-term contaminated soils using multispecies soil
systems
Supervisor:
Dr Gary Owens, Future Fellow – Mawson Institute, GPO Box 2471, Adelaide SA 5001, Australia
Phone: +61 8 8302 5043. Email: gary.owens@unisa.edu.au
Area: Environmental Science
Suitable for: PhD and Masters
Abstract:
Traditionally assessment of ecological risk uses a battery of independent biological assays
conducted sequentially. However an alternative to this process is to use a Multispecies Soil
System (MS-3) to conduct toxicity testing on contaminated soils simultaneously. The MS-3
system consists of soil columns coupled with a leachate collection system. Test species
(including plants and terrestrial invertebrates) are added to the column and their toxic
responses measured. Toxicity endpoints can include seedling emergence, root elongation,
plant biomass and earthworm mortality. Leachates can also be collected and toxicity assessed
via exposure to aquatic organisms such as Daphnia or alga.
This project will use a multispecies soil system to evaluate the ecotoxicity of a number of longterm contaminated soils from Australia and overseas. The study will combine plant growth
with soil solution extraction and worm assay to characterize the ecological risk posed by the
long-term contaminated soils. Plants and worms will be grown simultaneously in contaminated
soils and on harvest plants assessed for bioaccumulation of heavy metals and toxicity
symptoms. Sequential and in vitro extraction techniques will be used to correlate any observed
toxicity with solid phase speciation or bioavailability of the contaminant. Traditionally
assessment of ecological risk uses a battery of independent biological assays conducted
sequentially. However an alternative to this process is to use a Multispecies Soil System (MS-3)
to conduct toxicity testing on contaminated soils simultaneously. The MS-3 system consists of
soil columns coupled with a leachate collection system. Test species (including plants and
terrestrial invertebrates) are added to the column and their toxic responses measured. Toxicity
endpoints can include seedling emergence, root elongation, plant biomass and earthworm
mortality. Leachates can also be collected and toxicity assessed via exposure to aquatic
organisms such as Daphnia or alga.
This project will use a multispecies soil system to evaluate the ecotoxicity of a number of longterm contaminated soils from Australia and overseas. The study will combine plant growth
with soil solution extraction and worm assay to characterize the ecological risk posed by the
long-term contaminated soils. Plants and worms will be grown simultaneously in contaminated
soils and on harvest plants assessed for bioaccumulation of heavy metals and toxicity
symptoms. Sequential and in vitro extraction techniques will be used to correlate any observed
toxicity with solid phase speciation or bioavailability of the contaminant.
Related references:
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OECD, (1984). Guidelines for the Testing of Chemicals No. 207. Earthworm Acute Toxicity Tests.
B.R. Niederlehner, K.W. Pontasch, J.R. Pratt and J. Cairns Jr. (1990). Field evaluation of predictions of
environmental effects from a multispecies. microcosm toxicity test. Archives of Environmental
Contamination and Toxicology, 19(1), 62-71.
Marı´a Dolores Ferna´ ndez, Ekain Cagigal, Marı´a Milagrosa Vega, Arantzazu Urzelai, Mar Babı´n, Javier
Pro and Jose´ Vicente Tarazona (2005) Ecological risk assessment of contaminated soils through direct
toxicity assessment Ecotoxicology and Environmental Safety, 62, 174–184.
About Adelaide:
Adelaide is the capital of South Australia and offers a very high standard of living (top 6 in the
world according to “The Economist”), with great climate, food, wine, beautiful unspoiled
nature and beach environments, in an inexpensive setting.
The Mawson Institute (MI) has recently been established at the University of South Australia,
with strong support from the South Australian Government to research new manufacturing
technologies. Manufacturing is an important and substantial part of South Australia’s
economic base. The MI promotes a strategy based upon strong basic and applied research
that encourages scientific and technological innovation within the manufacturing sector.
Fundamental to this is the Institute’s multidisciplinary approach, building research teams in
concentrations that encompass a diverse range of disciplines, and collaboration with partners
from both academia and industry.
The institute is based in two new state-of-the-art buildings with outstanding research facilities
(see photo of the MM building).
For more information on this project please contact the supervisor.