Fig. 8.

Benchmark responses (BMR) for synaptogenesis. The absolute BMR value of single chemicals, calculated considering their nominal concentrations used in the mixtures ('5-Sim', '5-Diss', and '10-All'), are plotted and compared with the absolute percentage of response observed experimentally in the mixtures for each DNT endpoint (normalised to control). For some of these synaptogenesis features/treatment conditions (indicated by solid black arrows), the contribution of single chemicals revealed a response below the 5% threshold (TU ≤ 1), the percentage of response experimentally observed in the mixtures was > 1 (i.e., BMR > 5%), and the response induced by the mixture was at least two-folds of magnitude higher than the contribution of the most potent individual chemical. For those synaptogenesis features/treatment conditions indicated by dashed black arrows an interactive mixture effect can be hypothesized when the response elicited by the mixture was at least two-fold higher in magnitude than the most potent individual chemical, although the evaluation of the contribution of single chemicals revealed a response above the 5% threshold (TU > 1). Stars next to a single chemical (BDE47) indicate that the chemical may be considered as the main driver of mixture effects.