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RESEARCH PRODUCT

Sediment-associated retene bioavailability of sediment-associated retene to an oligochaete wormlumbriculus variegatus

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description

The bioavailability of retene spiked to two sediment concentrations (50 and 200 µg/g dry weight) was measured in long-term (28-day) bioaccumulation tests performed on the oligochaeteLumbriculus variegatus Muller. Three sediment organic carbon (SOC) concentrations (1.1, 3.0, 23.0% of dry weight) were used. Growth and reproduction, used as endpoints, indicated that retene was chronically nontoxic at the concentrations employed. Retene was clearly bioavailable, but bioaccumulated about 100 times less in the SOC-rich (23.0%) sediment than in the other two (SOC <3.0%). At the lower retene concentration, retene in the worms was undetectable in the high-SOC sediment. Based on final retene present at the end of exposure, the bioaccumulation factors (BAFs) ranged between 1.1–28.2. Normalization to organism lipid and SOC content diminished the variation, so that the biota-sediment accumulation factors (BSAFs) varied from 0.8 to 13.5. When calculated from initial retene concentrations, BAFs within the range of 0.04 to 5.3 and BSAFs from 0.1 to 2.5 were obtained. Results demonstrate that high levels of SOC diminish the bioavailability of sediment-associated retene inL. variegatus considerably. However, the remainder variation in the BSAFs suggests that besides of SOC and worm lipid contents there are also other factors that can affect the bioaccumulation dynamics of sediment-associated retene and the final outcome of its bioavailability.