Predicting the Ecological Risks of Phytoestrogens in Coastal Waters Using In Silico and In Vitro Approaches

Emerging pollutants, like phytoestrogens, are gaining attention in the scientific community for their impact on aquatic organisms. Nevertheless, there is a paucity of studies examining their effects on tropical aquatic species. In this context, the objective of this study was to (i) conduct chronic ecotoxicological assays with the sea urchin <i>Echinometra lucunter</i> with two phytoestrogens, namely genistein and daidzein (both derived from soy plant), and compare the results to the synthetic estrogen ‘estradiol valerate’; (ii) predict the potential risks of these phytoestrogens through an ecological risk assessment; and (iii) create a prioritization list of the most hazardous phytoestrogens using environmental persistence, bioaccumulation, and toxicity (PBT criteria). The results of chronic exposure demonstrated the following order of toxicity: daidzein (IC₅₀ = 2.60 mg/L); genistein (IC₅₀ = 3.37 mg/L); and estradiol valerate (IC₅₀ = 28.40 mg/L). The results classify genistein and daidzein as “toxic” and estradiol valerate as “harmful” to the sea urchin. The final ranking of the PBT approach in coastal waters was as follows: biochanin A (the highest priority), followed by formononetin, genistein, enterolactone, daidzein, estradiol valerate, coumestrol, and 8-prenylnaringenin. The dataset highlights the importance of environmental monitoring to track phytoestrogens in Latin American coastal areas, particularly in developing countries.