Heavy metals contamination in water, sediments and fish of freshwater ecosystems in Pakistan

Abstract

Freshwater ecosystems are being contaminated by heavy metals pollution. The primary source of contamination is wastewater discharged from urban, industrial, and agricultural facilities. The contaminated water contains hazardous amounts of heavy metals mixed in the freshwater ecosystem, causing deleterious impacts on marine life and humans. This review paper highlights the contamination of the freshwater ecosystem of Pakistan with heavy metals. Heavy metals concentration in sediments, water, and fish were assessed in the food chain, and their relationship with sites and sources was explored. It was observed that heavy metals present in freshwater and sediments bio-accumulate into fish organs. It was also found that some parts of freshwaters like River Ravi, Chenab, Kabul, and Indus were highly contaminated, and they posed negative impacts on fish and human health. River Ravi, receiving a huge amount of industrial and sewage wastewater from urban centers and industries of Central Punjab, was highly contaminated compared to other Rivers of Pakistan. The ecosystem health of River Indus was the best among all the rivers of Pakistan due to the enormous volume of water flow and less number of industrial units along with it. Freshwater fish of River Indus, Chenab, and Jhelum are consumable for humans. The presence of heavy metals also causes social, environmental, and economic problems. Therefore, the wastewater should be treated before discharge into freshwater streams and rivers to lessen the harmful impacts of heavy metals on marine life and human beings.

Evaluation of Chemical Elements, Lipid Profiles, Nutritional Indices and Health Risk Assessment of European Eel (Anguilla anguilla L.)

“…Aquatic ecosystems, both natural reservoirs and aquaculture systems, are contaminated with heavy metals [19]. According to Yousif et al [20], Agbugui and Abe [17], and Afzaal et al [21], heavy metals come from anthropogenic sources related to human activity (namely, industrial, agricultural and household waste, and by-products), as well as the combustion of fossil fuels and gasoline, and mining [22]. Garai et al [22] also mention natural sources of heavy metals, such as volcanic eruption and the weathering of metal-bearing rocks.…”

Assessment of Respiratory and Reproductive Impacts of Artisanal Refinery Activity on Male Albino Wistar Rats: Implications for Environmental Health

“…Pollutants released into water bodies can bioaccumulate in aquatic organisms, ultimately entering the human food chain (Sonone et al, 2020). Consumption of contaminated sh or crops irrigated with polluted water can result in the ingestion of toxic substances, leading to various health issues, including gastrointestinal disorders, organ damage, and systemic toxicity (Afzaal et al, 2022;Jaishankar et al, 2014).…”

A Review and Analysis of Heavy Metals in Freshwater Reservoirs of Pakistan: their Bioaccumulation, Biological Magnification and Biotic Transmission

“…Heavy metals are defined as "all naturally occurring metals with atomic numbers greater than 20 and elemental densities greater than 5 g/cm3" [11]. According to [12], "metals of natural or anthropogenic origin are pervasive in the aquatic environment, and it is therefore of great socio-economic importance to understand their behavior and interactions with aquatic life, especially fish, which are which are an important source of dietary protein that humans consumption."…”

“…The pollution level of the Indus River is significantly lower. Polluted river fish pose serious health risks to humans [11]. Similarly, this current review has tried to explain the major causes of heavy metal pollution in main freshwater reservoirs like the Rawal Dam, Mangla Dam, Zabi Dam, Changhoz, and Ghol Dams.…”