MOESM1 of Dioxin in the Elbe river basin: policy and science under the water framework directive 2000–2015 and toward 2021

Additional file 1. A wider overview on dioxin and historical contaminated sediments in the Elbe River basin before and during the first phase of implementation of the European Water Framework Directive, including controversial issues between administration and specialist science ([200], in German)

Understanding Receptor-Mediated Effects in Rainbow Trout: <i>In Vitro</i>–<i>in Vivo</i> Extrapolation Using Physiologically Based Toxicokinetic Models

The European REACH regulation requires the use of animal experimentation to assess the risk of industrial chemicals. However, the 3R principle (reduction, replacement, refinement) demands the use of suitable alternative test methods. Many dossiers submitted for the authorization of chemicals have attempted to provide the required data without performing new experiments, relying heavily on <i>in silico</i> methods; <i>in vitro</i> assays were scarcely used. We propose a methodology that uses physiologically based toxicokinetic (PBTK) models to extrapolate <i>in vitro</i> data to the <i>in vivo</i> level. We collected experimental results for <i>in vitro</i> and <i>in vivo</i> ethoxyresorufin-<i>O</i>-deethylase and vitellogenin induction following chemical exposure and compared those results with model predictions. We found that the predictive power of aqueous chemical concentrations was limited; median effect concentrations (EC50s) based on internal concentrations in fish correlated better with <i>in vitro</i> EC50s. Our data show that <i>in vitro</i> assays could offer a substitute for fish studies when combined with PBTK models

AhR-mediated activity of sediment extracts from the Yangtze River estuary.

<p>The values as determined by the EROD assay with RTL-W1 cells are expressed as biological toxicity equivalents (Bio-TEQ; pg/g dw). Data are given as means of 3 replicates ± SD.</p

The contribution of Chem-TEQs of PAHs to Bio-TEQs.

<p>The total biological response of the crude extracts in the EROD assay with RTL-W1 cells are expressed as bio-TEQs. The chem-TEQs of the 16 measured EPA PAHs were calculated by multiplying compounds concentrations and relative equivalency potencies and are given in pg/g dw. Numbers in percent indicated the calculated contribution of these PAHs to the EROD induction in each crude extract.</p

Concentrations of the 16 US EPA-polycyclic aromatic hydrocarbons (PAHs; ng/g dw) in sediment samples from the Yangtze River estuary.

<p>Note: n.d. = not detectable or below the detection limit.</p

AhR-mediated activities of crude and multilayer fractions of sediment extracts from the Yangtze River estuary.

<p>The results are based on EROD inductions with RTL-W1 cells and presented as bio-TEQs. F1 contains non-polar paraffinic components. F2 contains weakly and moderately polar components. F3 contains highly polar components. The numbers in percentage were calculated as (F1+F2+F3–CE)/CE×100%. The difference between the combined F1 to F3 and the induced crude extracts induction is given. Bio-TEQs are given as means of <i>n</i> = 3 independent experiments. CE, crude extracts.</p

Cytotoxicity of sediment extracts from the Yangtze River estuary.

<p>n.d. = not detectable, indicating that no toxic effect of sediment extracts at a concentration of 100 mg/mL with RTL-W1 cells. NR₅₀ values for sediment extracts are given in mg sediment equivalent per mL medium (mg/mL). All the values are expressed as means ± SD.</p

Cytotoxicity of sediment extracts of the Yangtze River estuary and that of other sediment extracts from previous studies.

<p>Cytotoxicity of sediment extracts of the Yangtze River estuary and that of other sediment extracts from previous studies.</p

AhR-mediated activity of sediment extracts of the Yangtze River estuary and those of other rivers described in previous studies.

<p>Note: n.d. = not detectable or below the detection limit.</p

Map of the sampling locations in the Yangtze River estuary.

<p>Nine samples Y1–Y9 were collected along the estuary in March 2012.</p