• Daoush, Walid

Abstract

Among toxic pollutants, Mercury (Hg) is a toxic heavy metal that induces harmful impacts on aquatic ecosystems directly and human being’s health indirectly. This study con rmed the in vitro magnetic potential of magnetite Nano-Particles (Fe3O4 NPs) against waterborne Hg exposure-induced toxicity in Nile tilapia (Oreochromis nilo- ticus). We further evaluate the safety pro le of Fe3O4 NPs onsh growth, hemato-biochemical, histological parameters, bioaccumulation in muscles, and economy. Magnetite nanoparticles were characterized, adsorption loading to Hg ions was investigated, and testing different concentrations of Fe3O4 NPs (0.2, 0.4, 0.6, 0.8, and 1.0 mg/L) was applied to determine the highest concentration of adsorption. An in vivo experiment includes 120sh with an average weight of 26.2 ± 0.26 g were randomly divided into 4 equal groups, each group had three replicates (n = 30sh/group; 10sh/ replicate). All groups were fed on a reference basal diet and the exper- iment was conducted for 30 days. Therst group (G1) was allocated as a control. The second group (G2) received 1.0 mg/L aqueous suspension of Fe3O4 NPs. The third group (G3) was exposed to an aqueous solution of Hg ions at a concentration of 0.025 mg/L. Meanwhile, the fourth group (G4) acquired an aqueous suspension composed of a mixture of Hg ions and Fe3O4 NPs as previously mentioned. Throughout the exposure period, the clinical signs, symptoms, and mortalities were recorded. The Hg ions-exposed group induced the following conse- quences; reduced appetite resulting in reduced growth and less economic ef ciency; microcytic hypochromic anemia, leukocytosis, lymphopenia, and neutrophilia; sharp and clear depletion in the immune indicators including lysozymes activity, immunoglobulin M (IgM), and Myeloperoxidase activities (MPO); signi cant higher levels of ALT, AST, urea, creatinine, and Superoxide dismutase (SOD); histological alterations of gill, hepatic and muscular tissues with strong expression of apoptotic marker (caspase 3); and a higher accumulation of Hg ions in the muscles. Surprisingly, Fe3O4 NPs-supplemented groups exhibited strong adsorption capacity against the Hg ions and mostly removed the Hg ions accumulation in the muscles. Also, the hematological, biochemical, and histological parameters were recovered. Thus, in order to assess the antitoxic role of Fe3O4 NPs against Hg and their safety on O. niloticus, andll the gap of the research, the current context was investigated toevaluate the promising role of Fe3O4 NPs to prevent Hg-exposure-induced toxicity and protection ofsh health, which ascertains essentiality for sustainable development of nanotechnology in the aquatic environment.

Topics

• nanoparticle
• impedance spectroscopy
• experiment
• laser emission spectroscopy
• toxicity
• Mercury