Incorporation of sediment- and soil-specific aspects in the Criteria for Reporting and Evaluating Ecotoxicity Data (CRED).

In environmental risk assessment either for registration purposes or for retrospective assessments of monitoring data, the hazard assessment is predominantly based on effect data from ecotoxicity studies. Most regulatory frameworks require studies used for risk assessment to be evaluated for reliability and relevance. Historically, the Klimisch methodology was used in many regulatory procedures where reliability needed to be evaluated.

Prioritization of substances for national ambient monitoring of sediment in Switzerland.

In Switzerland, surface waters are protected by the Swiss Water Protection Ordinance (OEaux; OFEV 1998), which stipulates that the water quality shall be such that the water, suspended matter, and sediments contain no persistent synthetic substances to ensure the protection of aquatic life. Local agencies are in charge of water quality monitoring, using a set of validated methods. Several lists of priority substances have been developed for aquatic microcontaminants for surface water monitoring but not for sediments.

The sediment-contact test using the ostracod Heterocypris incongruens: Effect of fine sediments and determination of toxicity thresholds.

The toxicity test using freshwater ostracods of the species Heterocypris incongruens is a sub-chronic static test that exposes individuals to whole sediments over a period of 6 d, the endpoints being mortality and growth. We tested the hypothesis that endpoints of the sediment bioassay using Heterocypris incongruens are affected by the presence of fine sediment particles by testing control sediment supplied with the commercial test kit with increasing proportions of kaolin clay as a proxy for fines. While mortality was not affected, the results showed that increasing the presence of clay reduced ostracod growth.

Arsenic toxicity in a sediment-dwelling polychaete: detoxification and arsenic metabolism.

The accumulation, subcellular distribution and speciation of arsenic in the polychaete Arenicola marina were investigated under different laboratory exposure conditions representing a range of metal bioavailabilities, to gain an insight into the physiological mechanisms of how A. marina handles bioaccumulated arsenic and to improve our understanding of the potential ecotoxicological significance of bioaccumulated arsenic in this deposit-feeder. The exposure conditions included exposure to sublethal concentrations of dissolved arsenate, exposure to sublethal concentrations of sediment-bound metal mining mixtures, and exposure to lethal concentrations of sediment-bound metal mining mixtures and arsenic- and multiple metal-spiked sediments.

Bioaccumulation of arsenic from water and sediment by a deposit-feeding polychaete (Arenicola marina): a biodynamic modelling approach.

Arsenic bioaccumulation in the deposit-feeding polychaete Arenicola marina has been investigated using biodynamic modelling. Radiotracer techniques were used to determine the rates of uptake of As as arsenate from water and sediment and its subsequent efflux in the laboratory. Lugworms accumulated As from solution linearly at concentrations of 2-20 microg l(-1), with a corresponding uptake rate constant of 0.