Akademik Veri Yönetim Sistemi
Environmental Toxicology and Pharmacology, cilt.125, 2026 (SCI-Expanded, Scopus)
The increasing release of engineered NPs into aquatic environments has raised concerns regarding their potential ecological risks. Among these materials, titanium dioxide NPs (TiO2 NPs) are widely used due to their chemical stability and photocatalytic properties, yet their effects on aquatic primary producers and consumers remain insufficiently understood. In this study, the physicochemical properties of commercially available TiO2 NPs were comprehensively characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) surface area analysis, and scanning electron microscopy (SEM). The NPs were identified as single-phase anatase with high purity, mesoporous structure, and a strong tendency to form agglomerates. Acute toxicity and biointeraction effects of TiO2 particles were evaluated using the freshwater microalga Chlorella vulgaris and the zooplankton Daphnia magna as representative primary producer and secondary consumer species. Algal growth inhibition assays revealed a pronounced concentration-dependent decline in biomass and chlorophyll (a + b) content, with near complete inhibition at concentrations ≥ 50 mg/L. SEM and EDS analyses showed extensive aggregation and surface attachment of TiO2 on algal cells indicating that physical coverage and reduced light availability are primary factors driving toxicity. Acute immobilization tests with D. magna showed increasing immobilization rates with rising TiO2 aggregates concentrations, with near-complete immobilization occurring at ≥ 100 mg/L. The Probit analysis for C. vulgaris growth inhibition established an EC₅₀ value of 16.57 mg/L with NOEL and LOEL values at 1 mg/L and 5 mg/L, respectively. SEM observations further confirmed nanoparticle attachment to the body surface and appendages of D. magna at high concentrations. Overall, the results demonstrate concentration-dependent responses in both species. Under high laboratory exposure levels, the toxic effects are mainly mediated by physical interactions and particle aggregation rather than nano-specific chemical toxicity.