Effects and ecological risk assessment of short chain chlorinated paraffins in soil.
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| Year of publication | 2005 |
| Type | Conference abstract |
| MU Faculty or unit | |
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| Description | Short-chain chlorinated paraffins (SCCPs) are industrial chemicals that enter the soil in high amounts (especially in sewage sludge) and then behave as typical persistent organic pollutants in soil ecosystem. Even SCCPs were studied for mammalian and aquatic toxicity, there are no data about their possible effects in soil. In our study, effects on several soil organisms were measured in order to fulfill these gaps in the ecotoxicological profile as was called in ECB Risk Assessment Report for SCCPs. Effects of model chlorinated paraffin C12, 64% Cl were tested on several soil invertebrates and microbial biomass of natural soil. The tested concentrations were 100, 320, 1000, 3200, and 10000 mg/kg. No mortality was recorded for Eisenia fetida and Enchytraeus crypticus at tested concentrations. Only small mortality (10-30%) was recorded for Folsomia candida at the highest concentration tested. The lowest statistically significant NOEC for reproduction of all species was 1000 mg/kg. EC50 for reproduction were approximately 3160 mg/kg for E. fetida, 2760 mg/kg for F. candida, and 7280 mg/kg for E. crypticus. Microbial biomass Cbio and basal respiration were not affected even at concentration 10,000 mg/kg. However, substrate induced respiration was inhibited to 43% at 10,000 mg/kg. Calculation of PNEC using assessment factor 50 was done according to ECB Technical Guidance Document. Finally PNEC 13.6 mg/kg was derived after conversion from OECD soil to a standard soil with an organic matter content of 3,4%. For risk assessment, model PECs (ECB RAR) for agricultural soils were used resulting in three risk quotients for different scenario: <0.01 after single application of sewage sludge, 0.8 for regional, and <0.1 for continental scenario. In conclusion, there is likely no ecological risk supposed in agricultural soils caused by SCCPs. Research supported from Grant Agency of Czech Republic project 525/04/P159. |
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