Assessment of metal pollution impacts on Tilapia zillii and Mugil cephalus inhabiting Qaroun and Wadi El-Rayan lakes, Egypt, using integrated biomarkers

Abstract

Qaroun and Wadi El-Rayan lakes are exposed to a huge amount of discharges from different sources and numerous anthropogenic activities. Therefore, the present work aimed to evaluate the impacts of metal pollution on two wild fish species; Tilapia zillii and Mugil cephalus collected from lake Qaroun (eastern and western parts) and Wadi El-Rayan lakes (upper and lower lakes). Accumulation of metals (Cu, Zn, Cd, and Pb) in water, sediment, and five vital tissues as well as metal pollution index (MPI), contamination factor (CF), and pollution load index (PLI) were integrated as metal pollution biomarkers. Generally, these integrated endpoints had the same trend and indicated that the eastern part of lake Qaroun was the most polluted site followed by the lower lake of Wadi El-Rayan. To assess the environmental genotoxicity, the percentage DNA damage in different tissues of both fish species was estimated using the comet assay technique. The percentage of DNA damages showed tissue-, species-and site-specification. Hazard index (HI) has been used as an evaluation index for human health associated with fish consumption at the studied sites. This index showed that all metals were in the safe limits at normal consumption levels while adverse health effects are expected to occur at the subsistence consumption level. The safe HI for each metal at normal consumption level does not neglect that the combined cumulative risk impact of all metals is a sign of warning and the health of fish consumers nearby contaminated sites is threatened.

The Potential Use of Orange and Banana Peels to Minimize the Toxicological Effects of Silver Nanoparticles in Oreochromis Niloticus

“…The high hepatic metal accumulation may be related to the high rate of metallothioneins (MTs) production, which gradually forms a chelate with metals to prevent potential injury. Furthermore, the liver is a powerful detoxifying organ that is responsible for the mitigation of several metals via sulfur metal protein complex formation (Abdel-Khalek et al 2020b ). Due to the important role of the renal reabsorption and excretion processes, the kidney is considered a potential metal accumulator.…”

Evaluation of the ecological health and food chain on the shores of four River Nile Islands, Egypt

“…The results indicated that Fe was the most accumulated element, followed by Zn and Cu, while Cd was the least accumulated one (Table 10 ). The rise in Fe accumulation in fish was higher than that of other metals, possibly because of the increase of total dissolved Fe levels in aquatic media (Abdel-Khalek et al, 2020 ). The concentrations of Cu, Pb, and Cd in both muscles and gills, and the Zn concentration in muscles were below the WHO/FAO FSG (FAO/WHO, 2010 ).…”

Long-Term Exposure to the Water of Wadi El-Rayan Lakes Induced Testicular Damage and Endocrine Disruption in Mugil cephalus

“…A total number of 45 adult males of M. cephalus were obtained with the help of local fishermen from the studied sites (n = 15/site). The fish sampling process was about one km 2 around the reported GPS (for each site) during the summer season of 2018, representing the period of the highest evaporation rate and maximum pollutant concentrations as reported by Abdel-Khalek et al (2020a). Fish samples were brought immediately to the ecology laboratory in ice tanks for biochemical and histological investigations.…”

“…This was done by transporting excess discharges into two man-made lakes (at two different altitudes) in the depression of Wadi El-Rayan. The upper lake collects wastewater effluents from the Wadi drain, then the surplus water streams via the shallow connection channel to the lower lake of Wadi El-Rayan (Abdel-Khalek et al 2020a). The growing chemical discharges and extensive water evaporation rates have led to several ecological changes and an elevation in pollutant concentrations of anthropogenic origin in both lakes.…”

“…The growing chemical discharges and extensive water evaporation rates have led to several ecological changes and an elevation in pollutant concentrations of anthropogenic origin in both lakes. Metals and organochlorine pesticides (OCPs) are known to be one of the most widespread contaminants in Wadi El-Rayan lakes (Zaghloul et al 2011;El-Sherif et al 2016;Abdel-Khalek et al 2020a). Many of those persistent pollutants are well known as endocrine-disrupting chemicals (EDCs) and their adverse impact on the reproductive capacity of fish has been documented in various toxicological studies (Sun et al 2016;Martyniuk et al 2020).…”