Exemplary concentration-response curve (carbazole) measured in the micronucleus assay with RTL-W1 cells (closed circles).

<p>The concentration-response curve for NQO (open circles) and the blanks, i.e. control cells without treatment (open square and lower dashed line), are given for reference. Induction factors are fold-changes relative to blanks. EC₂₅ values relative to the maximum induction of NQO (upper dashed line) were calculated to derive fixed-effect-level-based REPs. Concentration values on the x-axis refer to nominal medium concentrations of the substances. Circles represent mean values measured in duplicate experiments, error bars the standard deviation. The red line depicts 25% of the maximum induction caused by the standard NQO. Asterisks denote statistically significant differences compared to blanks (one-way ANOVA with Dunnet’s test, <i>p</i>≤0.05).</p

Corrected and uncorrected REPs relative to NQO, as well as respective corrected and uncorrected EC₂₅ values in the micronucleus assay with RTL-W1 cells.

<p>Chemical losses in the micronucleus assay used for calculation of corrected EC₂₅ (i.e. by multiplying the residual compound fraction with the EC₂₅) and REP values were derived from GC-MS measurements in 6-well microplates without cells.</p><p><i>n.d.: Inactive in assay system, i.e. substances which did not reach 25% induction of the NQO standard; n.a.: not available; STD: standard substance; LOQ: limit of quantification.</i></p><p>¹<i>Maximun tested concentrations based on cytotoxicity data from Hinger & Brinkmann et al.</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085692#pone.0085692-Hinger1" target="_blank">[<i>13</i>]</a>.</p

Content of total organic carbon (TOC) (%) and concentrations of the 16 US EPA-polycyclic aromatic hydrocarbons (PAHs) (ng/g dw) in sediment samples from the Yangtze River estuary.

<p>Note: The data of PAHs were obtained from Liu et al. (2014). n.d. = not detectable or below the detection limit.</p><p>Content of total organic carbon (TOC) (%) and concentrations of the 16 US EPA-polycyclic aromatic hydrocarbons (PAHs) (ng/g dw) in sediment samples from the Yangtze River estuary.</p

Dose-response curves in the micronucleus assay with RTL-W1 cells for all investigated heterocyclic compounds (closed circles).

<p>Standard curves for NQO (open circles) and blanks, i.e. control cells without treatment (open squares, grey line), are given for reference. Induction factors are fold-changes relative to blanks. Concentration values on the x-axis refer to nominal medium concentrations of the substances. Dots represent mean values measured in duplicate experiments, error bars the standard deviation. Asterisks denote statistically significant differences compared to blanks (one-way ANOVA with Dunnet’s test, <i>p</i>≤0.05).</p

Mutagenic activity of nine sediment extracts from Yangtze River estuary.

<p>Mutagenic measured by the Ames fluctuation assay using both TA98 and TA100 bacteria strain with and without bioactivation enzymes (S9). TA100 with or without S9 is not shown because no mutagenic effects were observed in any of the samples. Data are shown as maximum induction factor (IF_max) as the highest IF score of a particular sample within the dose-response curve. Multiple symbols indicate different significant levels relative to the negative control (NC): *<i>p</i><0.05, **<i>p</i><0.01.</p

Mutagenic activity of three fractions of samples Y2, Y7, Y8 and Y9.

<p>Mutagenicity measured by the Ames fluctuation assay using TA98 bacteria with and without bioactivation enzymes (S9). Mutagenic activity is expressed as maximum induction factor within the dose-response curve.</p

Map of the sampling locations in the Yangtze River estuary.

<p>Map of the sampling locations in the Yangtze River estuary.</p

Uncorrected and corrected relative potency (REP) values of hetero-PAHs.

<p>Uncorrected values refer to nominal concentrations and corrected to measured concentrations in the exposure medium after incubation without cells. <i>N.d.: inactive in assay system, i.e. substances which did not reach the stipulated level of 25% induction of the NQO standard.</i></p

Overview on NR₅₀/LC₅₀-values (symbols) and concentration ranges (bars) for the three potential biofuels 2-MF, 2-MTHF and EL for NR assay (cytotoxicity) and EROD assay (dioxin-like activity) and the fish embryo toxicity test (teratogenicity/embryotoxicity; (69)).

<p>The lack of symbols indicates that no EC₅₀ value could be obtained.</p

Overview of the potential biofuels.

<p>Overview of the potential biofuels.</p