Fördjupad miljöriskbedömning av förorenade markekologiska system.
Integrering av kemisk, toxikologisk och ekologisk information.
AbstractThe research project Liberation, supported by the European Commission under the Environment and Sustainable Development Programme (Fifth RTD Framework Programme) aimed at developing a decision support system for ecological risk assessment of contaminated sites has proposed a tiered system including the triad method. This method integrates contaminant chemistry and bioavailability analyses with observed ecotoxicological effects in soil and groundwater. In this study the triad method was used to perform a risk characterization of a former surface treatment and metal industry, now used for the student union buildings of the Mälardalen University in Eskilstuna, Sweden. On the site, high concentrations of copper, zinc and nickel have been detected in the soil in a preliminary investigation of contaminant levels with XRF. For performing the risk assessment of the site according to the triad method, contaminant bioavailability, soil metal concentrations and soil toxicity were determined and an ecological assessment was carried out on four selected soil samples (one reference soil and three samples with low (B), medium (C) and high (D) contaminant levels). Contaminant bioavailability was measured through leaching (ISO TC 190/S7) and biouptake tests (DGT). Metal concentrations in soil samples (acid digestion) and soil leachates were determined by ICP-MS. Ecotoxicity of the soil samples was measured in luminescent bacterial assays, whole soil direct-contact tests with a meiobenthic ostracod and growth inhibition tests using radish and white clover seeds. The assessment of the ecological status of the soil samples was performed by determination of microorganism C-mineralization, nitrification rates and a nematode inventory. The integrated results, according to the triad method showed an environmental risk for all soil samples; B = 0.79, C = 0.62, D = 0.90 with deviation B = 0.31, C = 0.68, D = 0.18. The high deviation of the soil samples B and C indicate an uncertainty in the assessment. For firm conclusions concerning if a remediation is necessary, more analysis should be performed. Soil sample D showed that the environmental risk is a direct result of the pollution degree. A clean-up is motivated at this point.The methodology described in this report is considered a possible starting point for carrying out improved environmental risk assessments. This is the aim of achieving sustainable remediation that is more favorable from an environmental and socio-economic perspective.