Ecological Risk Assessment for Contaminated Soils
Development of Triad Approach based System for Ecological Risk Assessment for Contaminated Areas of Kyrgyzstan: Integration of Data of Chemical Analysis, Bioindication and Bioassay of Soils
Tech Area / Field
- CHE-CAA/Control and Accounting/Chemistry
- ENV-EHS/Environmental Health and Safety/Environment
- ENV-MRA/Modelling and Risk Assessment/Environment
3 Approved without Funding
Institute of Biology and Pedology, Kyrgyzstan, Bishkek
- University of Saskatchewan / School of Environment and Sustainability, Canada, SK, Saskatoon\nGenesis Laboratories, Inc., USA, CO, Wellington\nLawrence Berkeley National Laboratory / Earth Sciences Division, USA, CA, Berkeley\nIndiana University / School of Public and Environmental Affairs, USA, IN, Bloomington\nU.S. Army Engineer Research and Development Center, USA, MA, Concord\nUniversity at Albany / Department of Geography and Planning, USA, NY, Albany
Project summaryThe goal of the project is to develop a high-effective system for an ecological risk assessment and risk-based decision making for anthropogenic ecosystems, with particular focus to soils of the Kyrgyz Republic. The project is focused on the integration of Triad data including chemical, biological and ecotoxicological soil markers to estimate the potential risk of soils from highly anthropized areas impacted by the deposition of different pollutants from mining and agricultural operations. We will focus on two technogenic areas of Kyrgyzstan: the former uranium-producing province, and the dairy-farm territory.
The ecological risk assessment framework requires the selection of assessment endpoints (potentially affected receptors and their attributes) and measurement endpoints (metrics used to assess the potential impact of contaminants on the receptors). This project is based on the quantitative methods for integrated risk assessment and management. Weight of evidence (WOE) methods are key components of ecological and human health risk assessments (Chapman,1990;1996; Chapman et al., 2002), and can be defined as a framework for synthesizing inpidual lines of evidence by using methods that are either qualitative (examining distinguishing attributes) or quantitative (measuring aspects in terms of magnitude) to develop conclusions regarding questions concerned with the degree of impairment or risk. Most WOE applications rely on the qualitative integration of perse lines of evidence (LOE), representing impact on ecological receptors and humans (Linkov et al., 2006, 2007, 2009). For purposes of this project, a quantitative methodology for weighing LOE will simultaneously accommodate qualitative and quantitative LOE. The methodology is based on multi-criteria decision analysis (MCDA), while concurrently retaining the advantages of other types of WOE methods such as insights from experts and the use of logical scientific arguments (Linkov et al., 2011).
Currently, Triad-based ecological risk assessment (ERA) and multi-criteria decision analysis (MCDA) for technogenic sites are not implemented in Kyrgyzstan. However, the vitality of such research is self-evident. There are about 50 tailing dumps and over 80 tips of radioactive waste, which are formed as a result of uranium and complex ores (mercury, antimony, lead, cadmium and etc) mining around the aforementioned unfavourable places. According to the Mining Wastes’ Tailings and Fills Rehabilitation Centre established in 1999 by special Government’s Resolution, one of the most ecologically dangerous uranium tailings is in Kadzhi-Say. Although uranium processing is no longer practiced in Kadzhi-Say, a significant number of open landfills and uranium ore storages remain abandoned along the vicinity of this settlement. These neglected sites have enormous problems associated with soil erosion and are known as “technogenic deserts”. The upper soil horizons are deprived of humus and vegetation, which favor the formation of low-buffer landscapes in the zones of maximum contamination. As a result, most of these areas are not re-cultivated and remain in critical environmental condition (Bykovchenko, et al., 2005, Suranova, 2006).
Another source of soil contamination in Kyrgyzstan is the animal waste from dairy farms, and represents a significant source of bacterial contamination in the soil. Moreover, nutrient overloading - through a one-time heavy application of nutrients over time, can contribute to the pollution of soil, surface, or ground water. Some micronutrients can even accumulate within levels that may prove toxic to plants and/or grazing animals. High salt levels are also found in animal wastes. Imbalanced nutrient levels may interfere with efficient use of the nutrients by the crop. An applied waste that provides N, P, K, and micronutrients may not provide them in appropriate ratios for many plants.
In our project, Triad data for assessing environmental risk and biological vulnerability at contaminated sites will be integrated. The following Triad-based parameters will be employed: 1) chemical soil analyses (revealing the presence of potentially dangerous substances), 2) ecological parameters (assessing changes in microorganism’s community structure and functions, bioindication); 3) toxicological bioassays (utilizing classical endpoints such as survival and reproduction rates, genotoxicity). The output will be consisted of 3 indexes: 1) Environmental Risk Index, quantifying the level of biological damage at population–community level, 2) Biological Vulnerability Index, assessing the potential threats to biological equilibriums, and 3) Genotoxicity Index, screening genotoxicity effects. Then, our approach will integrate a set of environmental Triad data to be obtained during project, which will be carried out in order to estimate the potential risk from soils of highly human-impacted areas, called Kadzhi-Say and Teploklyuchenka, which have been primarily impacted by deposition of heavy metals and excess of biogenic elements.
The proposed study is closely related to the activities of all participants. The basis of the development under this project proposal is previous studies of the project participants, in particular, concerning biocenosis mapping of Kyrgyz soils (Mamytova., 2003, 2010). Team participants have carried out series of investigations on interaction of humic substances with soil contaminants (Khudaibergenova, 2005). In addition, the team under the leadership of Dr. Terekhova has excellent scientific experience in the field of development of technical approach for ecotoxicological assessment of soils (Terekhova, 2007, 2011). Soil ecotoxicological estimation has been studied with a battery of tests using test-organisms of different trophic levels. Currently, bioindication of soils with various humus states is under study (Senesi, Yakimenko 2007; Yakimenko, et al., 2008). Project authors are currently researching the mechanisms of negative changes in the environments that have occurred due to various anthropogenic factors. For this work we have been using computer technologies and multidimensional mathematical analysis of databases (Shitikov, 2006).
In order to achieve our goals, we will need to:
- characterize the physical-chemical parameters of soils with different sources of contamination. This task includes: (i) gathering historical data about land use; (ii) planning soil sampling campaigns for model technogenic sites for correct selection of the reference; (iii) assessing the mineralogical parameters, structural soil features, basic chemical and organic matter content; (iv) mapping potential pollutant sources.
- describe the features of soil microbiota in the contaminated sites (in situ). Biological data (bioindication endpoints) will include classical synecological parameters of bacterial and microscopic fungal (micromycetes) communities: (i) species indices of the taxonomic persity of microbial communities; (ii) total biomass of bacterial and fungal cells, spores and mycelia; (iii) bio-morphological biopersity and viability of fungal biomass – spore-mycelia ratio; (iv) ratio of fungi and bacteria in the biomass of different samples of soil.
- study the functional characteristics of soil biota. This category of testing includes parameters of fermentation activity within the contaminated soils; determination of quantitative and qualitative content of enzymes which carry out oxidizing reactions - peroxidase, catalase, and the reaction of hydrolysis - amylase, urease in soils. In addition we will use a multisubstrate and respirometric testing to discriminate the fungal and bacterial activity after soil contamination by different pollutants.
- measure toxicological endpoints in different model test-organisms. Bioassay responses will be obtained from organisms which represent different trophic levels: (i). producers (green algae and higher plant); (ii) consumers (crustacens and protozoan, mammalian cell culture), (iii) reducers (luminescent bacteria and pure culture of micromycete).
- carry out the complex biological analysis (bioindication and bioassays) of model contaminated soil samples using laboratory experiments to investigate influence of humus substances on negative pressure of different kinds of pollutants. To detect non-quantifiable attributes of microbe communities - presence of dark- pigmented toxicant-resistant fungi, pathogenic microorganisms, etc.
- create decision-analytical model that relates the structural damage of the technogenic soils and soil cenoses and complex of chemical and biotic parameters with specific remedial and abatement decision using multi-criteria decision analysis.
Publications relevant to the project are listed below:
- Khudaibergenova B.M. Genetic variability and usage Drosophila melanogaster for ecomonitoring. 2005, Ilim, 120 p.
- Linkov I, Satterstrom FK, Kiker G, Batchelor C, Bridges T, Ferguson E. 2006: From comparative risk assessment to multi-criteria decision analysis and adaptive management: recent developments and applications. Environ Int 32(8):1072–93
- Mamytova B.A. Degradation and pollution of soils in the Kyrgyzstan. The bulletin of TORMENTS, 2010, 1 (19), 130-131.
- Mamytova B.A. Bioecology of soils of suburbs of Issyk-Kul. Bishkek, 2010, 118 p.
- Poputnikova T.O. and Terekhova V.A. Establishment of a Landfill Impact Zone on Soils Using Structural and Functional Modifications of Microbial Communities. Moscow University Soil Science Bulletin, 2010, 65 (2), 94–97.
- Senesi N., Yakimenko O.S. Soil Humus as the Factor of Ecosystems’ Sustainability in Natural Cataclysms – in: Natural cataclysms and Global Problems of the Modern Civilization – Special Edition of Transactions off the International academy of Science H&E, Baku-Innsbruck, 2007, 550-554.
- Shitikov V. K. Intellectual technologies of the structural analysis of ecological systems. Dissertation Dr.Sci.Biol., 2006
- Shitikov V. K, et al. 2003. Quantitative hydroecology: methods of system identification. Tolyatti: IEVB, RAS, 463 p.
- Terekhova V.A. 2011 Soil Bioassay: Problems and Approaches Eurasian Soil science,, 44 (2), 173-179.
- Terekhova V., Yakimenko O., et al. Transformations of Humic Substances by Micromycetes Revealed by Fluorescence Spectroscopy - Advances in natural organic matter and humic substances research 2008-2010. Proc. 15th Meeting of the IHHS Tenerife - Canary Islands. 2010 Ed.: J.A. González-Pérez, F.J. González-Vila & G. Almendros. 2, 544-547.
- Timofeev M.A., Terekhova V. A., and Kozhevin P.A. Biotesting for Cd Pollution in Soils. Moscow University Soil Science Bulletin, 2010, 65 (4), 178–181.
The proposed TRIAD-based approach will allow the development of effective and economicaly reasonable models to collect the operative ecological data and will spur the creation of practically valuable schemes and intellectual technologies of screening the informative indicator parameters. This is essentual for the subsequent monitoring of harmful impacts and ecological risk assessment for soils of defined territories.