Risk Assessment of Trace Element Contamination in Drinking Water and Agricultural Soil: A Study in Selected Chronic Kidney Disease of Unknown Etiology (CKDu) Endemic Areas in Sri Lanka

Abstract

Unexplained or unclear etiology of chronic kidney disease (CKDu) has been reported in Sri Lanka’s North Central Province (NCP) for more than two decades. Meanwhile, high exposure to heavy metals/metalloids and their accumulation are recognized as the origin of many acute and chronic diseases in certain vulnerable human tissues including kidneys. This study evaluates the contamination status of heavy metals/metalloids of the drinking water and agricultural soil in two CKDu endemic areas compared with a reference area in Sri Lanka based on common indexes and attribute of the commonly used fertilizers evaluated to identify the basic sources of toxic metals in the agricultural soil. Mean concentrations of heavy metals/metalloids such as Mn, Co, As, Cd, Pb, Cu, Zn, and Fe in drinking water of CKDu endemic areas were far below Sri Lankan water quality standards (permissible limits). In addition, all sampling locations dropped below the medium range of the heavy metal pollution index of water (HPI 15–40). Geoaccumulation indexes (Igeo) of soil reveal that paddy soil in CKDu endemic areas is being moderately polluted with toxic metals/metalloids such as As, Pb, Cu, Ni, Cr, Zn, and Cd. On the other hand, the application of fertilizers, which contained a high dose of toxic metals, could be the driving force for agricultural soil pollution, and limitless application of low-quality fertilizer would lead to more soil contamination with heavy metals. Hence, hazardous metals can be incorporated into the food chains via contaminated paddy soil.

Assessment of the Polluting Status of Sludge from a Physicochemical Water Purification Unit and Their Impacts on the Soil: Case of the Yato Station (Littoral-Cameroon)

“…When copper is found in the soil, it binds strongly to organic matter and minerals. Generally speaking, it is accepted that copper has low mobility in soils [20]. However, as in the case of the P1 profile, Baize [2] demonstrated that the transfer of copper could take place particularly in acidic soils such as in certain podzosols because of the pH which impacts its mobility through its speciation.…”

“…This suggests that there is multiple contamination of this sludge by TMEs. The pollution index greater than 1 in the sludge of the basins would be due to the high concentrations of TMEs coming from the accumulation of waste of all kinds, the less clayey texture of the sludge (%A<30) and the content of organic matter [20] because its very low clay texture facilitates the mobility of TMEs towards the outlets which are surface water and the surrounding soil. As a result, the layers of clay minerals are not numerous enough to capture the metal ions in the environment [7].…”

A Review on Scope and Challenges of Organic Farming in India

“…But the CKDu disease patients had been reduced from 2011 to 2014 due to shift of country towards the organic farming. Ministry of Health had launched a plan called 'Towards a Toxin Free Country' for promotion of organic farming and health of public (Perera et al, 2021).…”

Analysis of impaired kidney function in the community around the Morosi nickel mines

“…This poor environmental condition has clearly disrupted the community health. The water sources used to daily activities certainly affect the body's metabolism or organs, such as kidney damage ( 5 ). The kidney damage result in the inability of the glomerular kidney to filter and reabsorb food substances, such as protein.…”