Modeling and Risk Assessment of Tributyltin Accumulation in the Food Web of a Shallow Freshwater Lake

Abstract

Tributyltin (TBT) measurements in a food web in the freshwater Lake Westeinder are used to calibrate an integrated fate and bioaccumulation model with special attention given to exposure pathways. The Dutch ban on antifouling paints containing TBT is simulated with a load reduction scenario. By integrating Monte-Carlo sampling with a calibration procedure, probability distributions of TBT concentrations in the food web are matched to the measured variation in TBT concentrations. Subsequently, these distributions are used for a dynamic risk analysis of TBT accumulation in water, sediment, and the food web in the whole lake and a typical marina. Model predictions indicate a fast decrease of concentrations in water, suspended matter, and the zebra mussel Dreissena polymorpha. TBT concentrations in sediment, chironomids, amphipods, and benthivorous fish are predicted to decrease at a much slower rate. Simulations indicate that TBT in the sediment contributes significantly to uptake of TBT by several species. The relative proportion of sediment uptake increases for (partly) benthivorous fish after TBT load reduction. The model predicts low bioaccumulation risks for the whole lake, but substantial risks of TBT are calculated for fish and zooplankton in marinas, both before and during load reduction.

Maximum permissible and negligible concentrations for some organic substances and pesticides

“…Further specific food chain models e.g. that for the herring gull (Norstrom et al, 1991), the aquatic food chain of Gobas (1993), the benthic and pelagic food chain of Morrison et al (1997), or for Contaminants in Aquatic and Terrestrial ecoSystems (CATS) (Traas and Aldenberg, 1994;Traas et al, 1996), may be used to improve the methodology to include secondary poisoning. However, the more complex the food chain is, the less ecotoxicological and bioaccumulation data are available to fully identify the risk of secondary poisoning (Jongbloed et al, 1994).…”

Impact of triphenyltin acetate in microcosms simulating floodplain lakes. II. Comparison of species sensitivity distributions between laboratory and semi-field

“…It has been reported that TPT is transferred through the food web Traas et al 1996) and low concentrations could mediate effects through bioaccumulation, resulting in a more sensitive response than in the laboratory.…”

No such thing as a free meal: organotin transfer across the freshwater–terrestrial interface

“…Studies of TBT have typically been conducted in marine systems, with few from fresh waters (see Kannan, Senthilkumar & Sinha, ; Tessier et al ., ). There has also been a tendency to simply detail its occurrence or estimate trophic transfer between aquatic consumers only (Stab et al ., ; Traas et al ., ). Since organotins have been detected in chironomid imagos from brackish waters of the Baltic (Lilley et al ., ), we hypothesised that chironomids might be an important vector of organotins across ecosystem boundaries from freshwater to terrestrial ecosystems.…”