Impact of particle size and light exposure on the effects of TiO2 nanoparticles on Caenorhabditis elegans.

The increasing use of engineered nanoparticles in industrial and consumer products leads to a release of the anthropogenic contaminants to the aquatic environment. To obtain a better understanding of the environmental effects of these particles, the nematode Caenorhabditis elegans was used to investigate the organism-level effects and in vivo molecular responses. Toxicity of bulk-scale (∼160 nm) and nanoscale (21 nm) titanium dioxide (TiO2 ) was tested under dark and light conditions, following ISO 10872.

Sediment contact tests as a tool for the assessment of sediment quality in German waters.

A sediment contact test (SCT) battery consisting of five ecotoxicological test systems was applied to 21 native freshwater sediments characterized by a broad variety of geochemical properties and anthropogenic contamination. Higher plants (Myriophyllum aquaticum), nematodes (Caenorhabditis elegans), oligochaetes (Lumbriculus variegatus), zebrafish embryos (Danio rerio), and bacteria (Arthrobacter globiformis), representing various trophic levels and exposure pathways, were used as test organisms. The test battery detected sediment toxicity caused by anthropogenic pollution, whereas the various tests provided site-specific, nonredundant information to the overall toxicity assessment.

Modification of the umu-assay (ISO 13829) accounting for cytotoxicity in genotoxicity assessment: a preliminary study.

In this study, the umu-assay (ISO 13829) was modified by addition of the resazurin-reduction assay to assess the cytotoxic potential of toxins. The aim was to develop a test system that was capable of examining both genotoxicity and cytotoxicity on the basis of the metabolic health of the cells so as to provide a better assessment of the negative influence of toxic effects on the evaluation of genotoxicity. The test was established and validated with mitomycin C (MMC), 1,3-dinitropyrene (1,3-DNP), 4-nitroquinoline-1-oxide (4-NQO) and chloramphenicol (CHL) as toxins with known responses in the umu-assay.

Interlaboratory comparison of a standardized toxicity test using the nematode Caenorhabditis elegans (ISO 10872).

A ring test was carried out within the standardization process of ISO 10872 to evaluate the precision of the toxicity test for the nematode Caenorhabditis elegans. Eight different laboratories tested aqueous solutions of the reference substance benzylcetyldimethylammonium chloride as well as native sediments and soils for toxic effects on the growth and reproduction of C. elegans.

Assessing the importance of dietborne cadmium and particle characteristics on bioavailability and bioaccumulation in the nematode Caenorhabditis elegans.

To investigate the impact of multiple cadmium exposure pathways on bioavailability and bioaccumulation, Caenorhabditis elegans were exposed to either dissolved cadmium or to both particulate (dietborne) and dissolved cadmium. The dietborne metal exposure scenarios included evaluations of two bacteria species (Escherichia coli and Arthrobacter globiformis), varying bacteria concentrations, artificial particles (with different surface functional groups or coated with lipopolysaccharides), as well as a mixture of both bacteria and artificial particles. Total cadmium concentration in the nematodes was used as a proxy for total metal accumulation.

Reproduction of the estuarine and marine amphipod Corophium volutator (Pallas) in laboratory for toxicity testing.

The acute whole sediment bioassay with the estuarine and marine amphipod Corophium volutator (Pallas) is broadly used within Europe. Hitherto, the test is carried out with field-collected animals. In order to provide a more standardized and continuously available test organism reproduction and growth experiments were performed for a period of one year in laboratory under simulated summer conditions (light/dark 16:8 at 15, 19, and 23 degrees C).

Effects of phenanthrene on lemna minor in a sediment-water system and the impacts of UVB.

The objective of this study was to evaluate if the Lemna-bioassay is appropriate to test contaminated sediments. A mixture of sand was spiked with phenanthrene to investigate whether sediment-bound pollutants can affect the plants via direct contact of the roots or the underside of the leaves. After 24h of equilibration for sorption/desorption processes, the test was carried out in the sediment-water mixture, and another test was performed with the aqueous phase which was separated from the sediment.

Application of a sediment quality triad and different statistical approaches (Hasse diagrams and fuzzy logic) for the comparative evaluation of small streams.

In order to evaluate the ecotoxicological contamination of 12 aquatic sites in streams within the catchment area of the Neckar River, a sediment quality triad (SQT) approach was applied. In contrast to Chapman's original triad approach, not only sediments, but also surface waters were examined. In brief, to obtain a comprehensive insight into the potential ecotoxicological hazard, both acute toxicity and more specific effects such as mutagenic, genotoxic, teratogenic, dioxin- and estrogen-like responses were recorded.