Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries

Abstract

Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water.

Seasonal Evolution and Depth Variability of Heavy Metal Concentrations in the Water of Firiza-Strîmtori Lake, NW of Romania

“…a There are various sources of heavy metals in aquatic environment such as natural sources through geological weathering of the rocks and anthropic sources such as mining effluents, industrial effluents, domestic effluents, agricultural nonpoint source pollution, transport or recreational activities (boating, fishing, camping). Heavy metals occur in small amounts naturally and may enter into the aquatic system through leaching of rocks especially by rainwater, atmospheric deposition of airborne dust or industrial emissions, forest fires and vegetation [1,[3][4][5].…”

“…These processes lead to the accumulation of higher levels of heavy metals in sediments [4][5]. However, the dissolved species of heavy metals continuously undergo a chemical exchange with the suspended fraction and bottom sediments [6][7].…”

Monitoring of heavy metals in selected Water Supply Systems in Poland, in relation to current regulations

“…In the case of heavy metals monitoring, it's very important to take into account the accumulation of them in human organisms. That is why monitoring of heavy metals should be carried out in accordance with other principles which take into account the process of metal accumulation in consumer organisms [14][15][16][17][18][19][20][21][22]. The approach to this problem in Poland is fundamentally different from the proper approach, which may give a true picture of water quality in the network.…”

“…Water supply companies and sanitary inspection focus only on aspects shown if water quality meets the guidelines outlined in the Regulation of the Polish Minister of Health, the frequency and optimal localization of monitoring points aren't important for them. [15,19,21,22]. In the United States, the EPA recommends an individual approach to monitoring of heavy metals for which separate recommendations have been made.…”

Development and treatment procedure of arsenic-contaminated water using a new and green chitosan sorbent: kinetic, isotherm, thermodynamic and dynamic studies

“…Mainly, chronic arsenic intoxication causes skin problems, several types of cancer and affects all organs including the central nervous system and the development of children [2][3][4].…”