The Accumulation Potency of Bulk and Nano Zinc Metal and Their Impacts on the Hematological and Histological Perturbations of Oreochromis niloticus

Abstract

This study was carried out to comparatively evaluate the bioaccumulation potency of Zn bulk and nanoparticles in Oreochromis niloticus and to investigate the induced hematological and histological alterations. Fish were exposed to ½ LC50/96 h values of both bulk and nano Zn meal for 7, 14, and 28 days. Concerning metal bioaccumulation factor (BAF), the data displayed that zinc nanoparticles (Zn NPs) had more efficiency to penetrate the studied tissues such as the liver, kidneys, gills, skin, and muscle. Hematological parameters named red blood cells (RBC), hemoglobin (Hb), and hematocrit (Hct) values were altered in Zn NPs treated groups after 14th and 28th days while these hematological parameters recovered to some extent in bulk particles (BPs) treated groups at the end of the experimental period. The changes in hematological parameters were found to be time dependent. Blood indices such as mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) revealed the presence of normocytic normochromic anemia in the studied groups at the most exposure periods except microcytic hypochromic anemia at the 7th day of bulk particles exposed fish. Based on histological end points, several alterations in the gills, liver, and kidney tissues were observed. Severely deformations were observed at NPs treated fish groups which varied between adaptive changes to tissue damage at the end of exposure period. The deformations were recorded to be increased in NPs exposed fish compared to BPs treated fish throughout the study periods.