Dual and multiple exposures to metal oxide nanomaterials: Unveiling histological and oxidative stress dynamics in Mytilus galloprovincialis

Due to their increasing industrial applications, metal oxide nanoparticles (NPs) have emerged as significant environmental pollutants with potential ecotoxicological effects on aquatic organisms. This study evaluated the acute effects of binary and ternary mixtures of ZnFe?O? (10 mg/L), SiO? (10 mg/L), and NiO (100 mg/L) NPs on Mytilus galloprovincialis. Following 96-hour exposures, oxidative stress biomarkers (SOD, CAT, GST, MDA) and histopathological alterations were assessed in gill and digestive gland tissues. Notably, the ternary mixture induced significant elevations in MDA levels. Among binary combinations, SiO?–NiO NPs enhanced antioxidant responses, whereas NiO–ZnFe?O? NPs caused pronounced tissue damage. The results underscore that NPs in the environment may not act independently but rather interact additively or synergistically, thereby amplifying their toxic potential. These findings highlight the need to consider mixture effects in ecotoxicological risk assessments, reflecting the complex and multicomponent nature of nanoparticle pollution in real-world aquatic environments. © 2025 Elsevier B.V.