Which chemical poses greater ecotoxicological risk: Bisphenol Z or Bisphenol A diglycidyl ether? A comparative study on <i>Phaeodactylum tricornutum</i> and <i>Mytilus galloprovincialis</i> in aquatic environments

This study investigated the ecotoxicological effects of Bisphenol Z (BPZ) and Bisphenol A diglycidyl ether (BADGE) on the marine diatom Phaeodactylum tricornutum and the mussel Mytilus galloprovincialis. The algal growth inhibition test, conducted according to OECD guidelines, demonstrated that BPZ and BADGE both significantly inhibited the growth of P. tricornutum, with IC50 values of 5.16 and 11.71 mg L-1, respectively. Acute toxicity tests on M. galloprovincialis indicated LC50 values of 11.24 mg L-1 for BPZ and 15.40 mg L-1 for BADGE over a 96-hour exposure. Physiological assessments over a 14-day exposure period revealed that both BPZ and BADGE significantly reduced the Condition Index (CI) and Gonadosomatic Index (GSI) of M. galloprovincialis. Specifically, BPZ led to a 42% decrease in GSI at the highest concentration (32 mg L-1), while BADGE resulted in a 40% decrease under similar conditions. Additionally, fertilization success tests showed that BPZ had a more pronounced negative impact on fertilization rates compared to BADGE, particularly at higher concentrations. These findings suggest that BPZ exhibits a higher ecotoxicological risk compared to BADGE, affecting both the growth of marine diatoms and the physiological and reproductive parameters of mussels.