Comparison between average EC50 for LREE (La to Gd) and HREE (Tb to Lu) using nominal and Time-Weighted Mean (TWM) EC50 and, first series of tests only, EC50 based on the estimated concentration of free LN3+ ions.

Caveats, recommendations and open issues for properly testing LN ecotoxicity to Daphnia magna and aquatic organisms in general. This is an expanded version of Table 2 in the main text).

Statistical significance of the regression coefficients for the relationships between atomic mass and Time Weighed Mean (TWM) effect concentrations (EC50) for the different experiments.

Calculation of toxic units (TU) for the maximum tested concentration of each lanthanide and of the corresponding counterion.Column A: Symbol of the chemical element.Column B: First ‘1’ or second ‘2’ run of definitive tests.Column C: 48h EC50 values observed for each element (nominal values) in mg/L.Column D: Maximum tested concentration for each lanthanide (mg/L).Column E: Toxic units of each LN at the maximum tested concentration (ratio between maximum added concentration and the corresponding 48h EC50).Column F: counterion added along with each LN (see also Table S1).Column G: Minimum EC50 value (in mg/L) reported in literature studies for the counterion (see section 4.4 in the main text).Column H: Maximum added counterion concentration (mg/L) in the experiments performed in the present study. Note that this is not the couterion concentration added along with each LN, but the absolute maximum added concentration across the entire lanthanide series in order to have a worst-case scenario.Column I: Toxic units for each counterion (ratio between maximum added concentration and the corresponding EC50).Column J: Percengage ratio between the TU for LN and the counterion. This indicate the potential contribution of the counterion to the total ecotoxic effect of the LN + counterion mixture.

Theoretical solubility limits of lanthanides (in mg/L) in the test medium ISO 6341 for the crustacean Daphnia magna at different pH values.

Values of EC10 and EC50 for D.magna exposed to lanthanides over 24 h and 48 h according to the ISO 6341 protocol.Column A: symbol of the chemical element.Column B: First ‘1’ or second ‘2’ run of definitive tests.Column C: EC10 values after 24 h of exposure.Columns D and E: Lower (LCL) and Upper (UCL) 95% confidence limits of the EC10 values in column C.Columns F, G and H: EC50 values after 24 h of exposure and corresponding 95% LCL and UCL.Column I: EC50 values after 24 h of exposure estimated using the Time Weighted Mean (TWM) approach.Columns J, K and L: EC10 values after 48 h of exposure and corresponding 95% LCL and UCL.Columns M, N and O: EC50 values after 48 h of exposure and corresponding 95% LCL and UCL.Column P: EC50 values after 48 h of exposure estimated using the Time Weighted Mean (TWM) approach.

Estimated values of Time Weighed Mean (TWM) EC50 for specimen of D. magna exposed to lanthanides over 24h or 48h and for both rounds of definitives tests. The TWM EC50 were estimated using equations 4 and 5 in the main text and following the procedure described below.Column A: symbol of the chemical element.Column B: atomic mass of each chemical element.Column C: First ‘1’ or second ‘2’ run of definitive tests.Column D: Expsoure time (in hours)Column E: EC50 values (nominal concentrations) for each element, test series (column C) and exposure time (column D).Column F: Equation number (numbering in the main text) used to estimate the decrease in the exposure concentration over the test duration.Column G: Estimated losses (%) calculated from the nominal EC50 values (column E) and the relationship between atomic mass and concentration losses (column F).Column H: Estimated concentrations (%) remaining at the end of the test (100 – values in column G).Column I: Estimated concentrations (in mg/L) remainig in solution at the end of the test.Column J: Time Weighed Mean (TWM) concentrations (in mg/L) calculated using equation 2 in the main text (see explanation below for the details).Column K: Experimentally measured concentrations (filterable 0.45 µm) at t=0h in solution amended with nominal concentrations indicated in column E. This information is available only for series 1 and Time 24h.Column L: as above, but with measurements at t=5hColumn M: as above, but with measurements at t=24hColumn N: Time Weighed Mean (TWM) concentrations (in mg/L) calculated for the experimentally measured values in columns K and M using formula 2 in the text.Column O: Geometric mean (in mg/L) calculated for for the experimentally measured values in columns K and MColumn P: Time Weighed Mean (TWM) concentrations (in mg/L) calculated for the experimentally measured values in columns K, L and M using formula 8 in the text. Notes and assumptions:a) Concentration decreases were experimentally measured in solutions spiked with lanthanides at the correspoding 24 h EC50 for the first round of tests (sections 3.1 and 3.2 of the main text).b) A relationship existed between atomic mass and percentage concentration decrease after 24 and 48 h for the above EC50 data (equations 4 and 5 in section 3.2 and Figure 3A in the main text).c1) For the second round of tests, equation 4 was assumed to hold for solutions initially spiked with lanthanides at the corresponding 24 h EC50. No experimental verification was performed for this.c2) For both rounds of tests, equation 5 was assumed to hold for solutions initially spiked with lanthanides at the corresponding 48 h EC50. No experimental verification was performed for this.Under assumptions c1 and c2, the TWM EC50 were estimated using a three step procedure. An example is provided below using Gd as a model element, for the first round of tests and the 48h EC50.Step 1. Estimation of the percentage concentration decrease.The concentration decrease for theoretical solutions initially spiked with LN concentrations equal to the nominal 48h EC50 was estimated using equation 5 (result is given in cell G22 of the CSV file).Step 2. Estimation of concentration remaining in solution after 48 h.The percentage concentration remaining in solution after 48h was estimated by the formula '100 - results of step 1' (cell H22 of the CSV file))The concentration (in mg/L) remaining in solution after 48 h in was calculated by multiplying the results in cell H22 by the nominal EC50 (cell E22) and dividing by 100.Step 3. The TWM EC50 48h was estimated using formula 2 in the main text.Here is the example with the corresponding figures:Nominal 48h EC50 (mg/L) for Gd in the first round of definitive tests: 6.2Expected % decrease in concentration after 48h 74.1%Estimated % concentration remaining is solution after 48h: 25.9%Estimated concentration remaining in solution after 48h: 1.61 mg/LEstimation of the TWM EC50 at 48h using formula 2 in the main text: 3.40 mg/L

This readme file contains the captions of all tables and figures in the database.

Statistical significance of the regression coefficients for the relationships between atomic mass and Time Weighed Mean (TWM) effect concentrations (EC50) for the different experiments.

Caveats, recommendations and open issues for properly testing LN ecotoxicity to Daphnia magna and aquatic organisms in general. This is an expanded version of Table 2 in the main text).