Chapter 13
Design of test batteries and interpretation of bioassay results
In the Excel sheet “Exercise Iceberg modelling” you find the underlying data of Glauch and Escher (2020), DOI: 10.1002/etc.4873 from the combined algae test.
a) In the tab "BEQbio" you find the EC10 values of all three endpoints of the combined algae test for two sampling sites and also of the reference compound diuron. Please calculate the BEQbio from this data.
b) In the tab "REP" you find the EC10 of all three endpoints from the combined algae test of the 29 individual chemicals that were detected in the water samples and for which you also have bionanalytical data. Please calculate the relative effect potencies REP.
c) In the tab "BEQchem" you find the concentrations of the detected chemicals. Please calculate the BEQchem.
Now you got all the information you need to start interpretation of your results:
d) Are there any chemicals that are risk drivers?
e) Calculate the BEQunknown. Based on the result, explain if the endpoints are Category 1 or Category 2 assays.
In the Excel sheet “Exercise EBT 1” you find data from Escher et al. (2018), DOI: 10.1016/j.scitotenv.2018.01.340 from the Tox21_ERa_BLA_agonist assay. There are also environmental quality standards (EQS) given for the test chemicals.
a) Please fill the empty columns of the table by calculating the REP and BEQ of all chemicals and the E10/EQS ratios.
b) Please calculate the EBT for this assay with and without a filtering step using the given formulas.
In the Excel sheet “Exercise EBT 2” you find data from Escher and Neale (2021), DOI: 10.1002/etc.4944 from the ARE assay. The table shows effect concentrations and IC10baseline concentrations from the ARE assay.
a) Calculate the SRbaseline for all chemicals.
b) Use the calculated SRbaseline to derive a EBT-BEQ for the assay in mgdichlorvos/L.