Accumulation of heavy metals in tilapia fish species and related histopathological changes in muscles, gills and liver of Oreochromis niloticus occurring in the area of Qahr El-Bahr, Lake Al-Manzalah, Egypt

Abstract

Accumulation of metals (Fe, Zn, Cu, Mn, Pb, Cd and Ni) in the muscles and gills of Oreochromis niloticus, Oreochromis aureus and Tilapia zillii was assessed based on seven locations in the Qahr El-Bahr area in Lake Al-Manzalah. The average accumulation of metals was in the following order: Tilapia zillii > Oreochromis aureus > Oreochromis niloticus. To determine the risk of fish consumption, the estimated daily intake, carcinogenic, non-carcinogenic and relative risk indices were calculated. The results indicate that the intake of individual metals through the consumption of fish is almost safe for human health, whereas the intake of combined metals poses a high potential health risk to consumers. Assessment of carcinogenic risk of Cd and Ni from the consumption of tilapia species indicates that consumers are at risk of cancer. The contribution of Pb and Cd to the overall relative risk index ranged from 34% to 41%. Of the three species studied, Oreochromis niloticus is relatively safe for consumption as it poses the least health hazard, while Tilapia zillii is more predisposed to accumulate metals in its tissues. Histopathological changes were observed in the muscles, gills and liver of Oreochromis niloticus as a result of heavy metal accumulation in these organs.

Effects of heavy metal contamination on Oreochromis niloticus (Tilapia fish)

“…The effects of lead might be attributed to its ability to generate reactive toxic action oxygen species. The Lead induce oxidative damage in several tissues by enhancing lipid peroxidation that occurs readily in the tissues, due to presence of membranes rich in polyunsaturated fatty acids (Mahmuda et al, 2020;Yacoub et al, 2021;Simukoko et al, 2022).…”

Histopathology and Ultrastructure in Liver and Gonads of the Nile Tilapia (Oreochromis niloticus) as a Bio-Monitor for Water Quality Assessment in Lake Manzalah

“…They are typically regarded as the best species for determining how environmental changes affect organisms, and they are employed as bio-indicators to track water pollution in aquatic ecosystems (Kuklina et al, 2013). The exposure of fish in Lake Manzalah to diverse pollutants causes several pathological changes in the fish organs (Yacoub et al, 2021).…”

Heavy Metal Bioaccumulation and Related Histopathological Changes in Gills, Liver and Muscle of Solea aegyptiaca Fish Inhabiting the Lake Qarun, Egypt.

“…Meanwhile, the MTs are able to form stable chelates with Pb The liver is the main metabolic organ, the amount of pollutants in fish liver is directly proportional to the degree of pollution in the aquatic environment (Yılmaz, 2009; Tapia et al, 2012). Many experimental and field studies showed that liver was the target organ for the accumulation of many metals and was highly active in the uptake and storage of metals because of its role in the storage, redistribution, detoxification, transformation of contaminants and the high induction rate of metallothioneins (MTs) in the liver (Dural et al, 2007;Yılmaz et al, 2010). In this context, liver has been recommended by many authors as the best environmental indicator of both the water pollution and chronic exposure to heavy metals (Agah et al, 2009;Messaoudi et al, 2009).…”