Toxicity Evaluation of Arsenic Nanoparticles on Growth, Biochemical, Hematological, and Physiological Parameters of Labeo rohita Juveniles

Muhammad Akarm Raza,Ambreen Shahid,Shahzad Naseem,Shafaq Fatima,Zakia Kanwal,Amna Sajjad,Saira Riaz,Angela De Bonis

doi:10.1155/2021/5185425

Abstract

The present study aims to assess the induced nanotoxicity of arsenic nanoparticles (AsNPs) on different organs of fresh water fish Labeo rohita. AsNPs were synthesized by chemical reduction method using sodium arsenite as precursor, ice-cold sodium borohydride as reducing agent, and sodium hydroxide to adjust the solution pH. The synthesized AsNPs were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) for optical, structural, and morphological investigations. The UV-Vis absorption peaks occurring at around 300 nm indicated the presence of AsNPs in colloidal sample. The rhombohedral crystalline nature and metallic purity of AsNPs with crystallite size of 30 ± 1 nm were confirmed by characteristic peaks of XRD pattern. The SEM micrograph revealed the almost spherical shape and 40 ± 10 nm average size prepared AsNPs. For assessment of induced nanotoxicity, juveniles of Labeo rohita (L. rohita) were exposed to three different concentrations of AsNPs (namely, 1, 10, and 20 mg/L) for 30 days (n = 15 per group), and the control fish was kept untreated. It was observed that the routine behavior activities (such as swimming, mutual interactions, and feed intake) were affected by AsNPs. The growth of AsNPs treated fish was found retarded as compared to the control fish. Total erythrocyte count, total leukocyte count, and hemoglobin and hematocrit values were low in the AsNPs treated fish. Immunobiochemical assays revealed that protein level was altered in the AsNPs treated fish. The levels of antioxidant enzymes catalase and superoxide dismutase were low in the treated fish. The histological alteration induced by AsNPs in liver, gills, and kidneys demonstrated the damage in form of glomerulus shrinkage, vacuolation, inflammation, necrosis, lamellar disorganization, and hemorrhage in comparison with untreated fish. The results of the present study indicate that AsNPs exposure causes behavior, growth, hematology, immunobiochemical, and histological shortcomings in L. rohita.

Highlights

Environmental toxicology includes the study of hazardous effects of chemicals on living organisms in the environment
4.54 ml of NaAsO2 stock solution was added to 100 ml of water, and pH was maintained between 7 and 9 by adding appropriate amount of sodium hydroxide (NaOH). 5 ml of ice-cold NaBH4 was added to the precursor solution; the whole mixture stood for 2 hours and was heated for 20 min at 60°C
In the synthesis process of Arsenic nanoparticles (AsNPs) by wet chemical reduction approach, solution reaction went through different phases which can be observed by the change of color of the solution as shown in Figure 1. e potential mechanism for the formation of AsNPs can be explained as follows: first of all, as precursor (NaAsO2) is dissolved in the water, arsenite ions (As3+) are produced in the solution and no color change occurred in the solution (Figure 1(a))

Summary

Introduction

Environmental toxicology includes the study of hazardous effects of chemicals on living organisms in the environment. Developing technologies and industries are the main cause of environmental pollution that is harmful to aquatic life because industrial and agricultural wastes are usually released into water resources [1]. It is, very important to recognize and oversee the sources of environmental pollution, to handle their harmful effects on aquatic ecosystems. Owing to large surface to volume ratio, nanostructures have great applications in many fields [7] Besides these advantages, there exist some concerns to nanotechnology. Nickel nanoparticles cause decrease in antioxidant enzymes in liver and gills of Oreochromis mossambicus. We previously have found that silver, nickel, cobalt, and chromium oxide nanoparticles cause various levels of toxicity in Labeo rohita on growth, hematological, histological, and biochemical indices [13]

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