PARENT SESSION
4F Alternatives for risk assessment in terrestrial ecosystems
9:00 AM to 7:00 PM, Monday, 07 May 2001

(M/MF159) Comparison of the kinetic behaviour of ¹⁴C-Lindane in isopods and enchytraeids.

Amorim, Monica^1,2, Loureiro, Susana^1,2, Sousa, Jose¹, Nogueira, Antonio ¹, Soares, Amadeu^1,2, ^{1 2}

ABSTRACT- An achievable way to evaluate the bioavailability of a certain toxic substance in the environment is to measure the concentration inside organisms. In the present study, bioaccumulation of the pesticide ¹⁴C-Lindane (-HCH) in Enchytraeus albidus and Porcellionides pruinosus is assessed in two different soil types: OECD standard artificial soil and a natural soil from an agricultural field in Central West Portugal. The study of these two detritivorous species is important due to their key role in decomposition processes in the edaphic system and to their different life strategies. In order to study bioaccumulation in the two edaphic species, toxicokinetic models were used, evaluating the assimilation rate and the elimination rate constant for these two species in two different soil types. When comparing the two soil types, isopods showed similar toxicokinetic parameters, while enchytraeids presented different values. Although the degradation rate in both soils presented significant values when enchytraeids were tested, when isopods were studied, the -HCH concentration was similar during the test period. The BAF values obtained for Enchytraeus albidus were significantly higher than the values found for Porcellionides pruinosus. These and other results are discussed in terms of life strategy of the tested species and the importance of having bioaccumulation data for different species is addressed.

Key words: toxicokinetics, enchytraeids, isopods