Sources and Toxicological impacts of Surface Water Pollution on Fish in Egypt

Abstract

Egypt has been listed as one of the most popular nations which are menaced through lack of water by the year 2025 due to overpopulation. The great deposition of highly polluted domestic and industrial effluents into its water ways, made a continuous and prompt damage to its surface and groundwater. The River Nile represents about 97% of Egypt's water resources; however winter rain and nonrenewable groundwater aquifers are also comprised. In Egypt, the main source of pollution is industrial wastes that are poured directly into the main water sources or through the municipal system. On the other hand, the pollution of the Mediterranean coast of Alexandria is mainly due to the discharge of wastes of industrial plants into the sea via Lake Marriott. The provincial populations have little or even no entry to drainage systems or wastewater treatment facilities and they rely only on theelimination of wastewater at the site of their production or collection. In the Delta region, drainage water is reused for irrigation after mixing with Nile water, while in Upper Egypt drainage water is disposed into the River Nile. Fertilizers and pesticides have been used on a wide range after the constructions of High Dam which resulted in weed flourishing which blocks the waterways, and provides habitats for Bilharzia snails. Egyptian fish aquaria exposed to toxicity due to water pollution from chemical plants and sewage pipes. Heavy metal pollution of Egyptian water is primarily produced by industrial and agricultural discharges. Other sources also include: coal and oil combustion, phosphate fertilizers, plastics and pesticides. Recently, the consumption of contaminated fish has been the possible cause of heavy metal poisoning in human. The aim of this review is to disclose the fundamental origin of water pollution in Egypt, and to elucidate the side effects of this pollution on fish.

Pesticides and heavy metal toxicity in fish and possible remediation – a review

“…Marigoudar et al (2009) revealed that cypermethrin caused erratic swimming, loss of balance, hyperactivity in rohu, Labeo rohita. Histopathological changes in different fish tissues due to pesticides toxicity also documented by several studies (Mohammed et al, 2019;Ghafarifarsani et al, 2023a). Thiamethoxam and chlorpyrifos caused several liver pathologies including necrosis, vacuolation, hemorrhages etc.…”

Seasonal variations of water physico-chemistry, heavy metal concentrations and ecological abundance and biodiversity of fish from two Lagoon streams

“…However, the high Cd contents obtained in this study might be attributed to the discharge of wastewater or Cd-containing effluents by industries in operations within the study areas since Cd is known to be present in most chemicals used for manufacturing several industrial products. Cd, if ingested and subsequently bioaccumulated in fish, might impair fish reproductive organs and, as a result, result in low fish production [15]. Other effects are damage to fish tissues, the immune system, and bone mutilation.…”

“…The fish population also responds negatively to factors such as overfishing, pollution, and eutrophication, among other environmental situations. This, however, can bring about a series of changes in the size, species composition, and abundance of fish populations [15]. The major factors responsible for the abundance, availability, and assemblage of fish within a particular water body are classified into abiotic and biotic factors [16].…”

An Overview on the Potential Hazards of Pyrethroid Insecticides in Fish, with Special Emphasis on Cypermethrin Toxicity

“…Pesticides, such as malathion, carbofuran, diazinon, and dichlorvos, caused several histopathological alterations, and affected the biological functions of some vital organs such as the kidney, liver, gills, testis, and ovaries of different fish species, in the form of necrotic changes, loss of the granularity of cytoplasm, shrinkage of cells in various tissues, nuclear pycnotic alterations, vacuolation in the cytoplasm (in gill lamellae, kidneys, and filaments), degeneration of glomerulus, shrinkage of nuclear materials, ruptured epithelial lining, cytoplasm clumping, altered tubular line size, degeneration of follicular cells, collecting duct damage, and changes in ovigerous lamellae in many fish species, including L. rohita, Heteropneustes fossilis, C. carpio, Channa punctatus, O. mossambicus, Nile tilapia (O. niloticus), and Cirrhinus mrigala [33,[46][47][48].…”