Exploring the Root Cause for Chronic Kidney Disease of Unknown Etiology (CKDu) via Analysis of Metal Ion and Counterion Contaminants in Drinking Water: A Study in Sri Lanka

Abstract

The introduction of elevated amounts of foreign ions into the blood may lead to impairment of the filtration membrane of kidneys and chronic kidney damage. In order to assess the risk of consumption of drinking water (dug well water) in chronic kidney disease of unknown etiology (CKDu), affected areas in Sri Lanka, trace metals, and other counterions in water samples obtained from dug wells were analyzed and compared with a reference area. Drinking water could be the major source that is responsible for entering nephrotoxic ion contaminants into the human body. To achieve the objective, drinking water samples were collected from dug wells in two CKDu endemic areas and a reference area where no CKDu patients were found in a dry season. In the Wewelketiya area (one of the endemic areas), Cd concentrations in 60% of water samples and Pb concentrations in 40% of water samples have exceeded the maximum limit given by Sri Lanka water quality standards. Fluoride concentrations also have exceeded the permissible limits of more than 80% of collected water samples in both CKDu endemic areas. However, none of the water samples in reference areas has reported that Cd, Pb, and fluoride are beyond their maximum permissible limits. Hence, people in the particular CKDu endemic areas are at risk of kidney tissue damage due to long-term exposure to drinking water with elevated levels of some metal ions and counterions.

Electrospun amine-functionalized silica nanoparticles–cellulose acetate nanofiber membranes for effective removal of hardness and heavy metals (As(v), Cd(ii),Pb(ii)) in drinking water sources

“…The heavy metal concentrations in the mixture were decided based on the highest reported contamination of drinking water sources in CKDu prevalent areas. 35,36 The membrane was then dipped in 30 ml of food grade vinegar solution for 1 hour and washed with deionized water several times. The recycled membrane was then used in the subsequent adsorption of cation mixtures.…”

Multi-pronged research on endemic chronic kidney disease of unknown etiology in Sri Lanka: a systematic review

“…Fluoride (F -) exposure via drinking water and its gradual accumulation in the body is nephrotoxic Nanayakkara et al 2020aNanayakkara et al , 2020bPerera et al 2020;Thammitiyagodage et al 2017). The synergistic influence of Fand water hardness can enhance CKDu (Balasooriya et al 2019;Wickramarathna et al 2017), particularly when high elevated levels of Mg 2+ contribute to water hardness Wickramarathna et al 2017).…”

“…Even though long term Cd exposure is widely suggested to be the main cause of CKDu (Ananda Ananda Jayalal et al 2019;Bandara et al 2008;Jayatilake et al 2013;Perera et al 2020;Wanasinghe et al 2018), an equal number of studies exclude Cd as a causative factor (Ayala Herath et al 2018;Chandrajith et al 2011aChandrajith et al , 2011bDiyabalanage et al 2017;Nanayakkara et al 2014Wickramarathna et al 2017).…”

“…Almost all agrochemicals, especially phosphate fertilizers used by farmers in the NCP, are contaminated with As and provide a strong source of this heavy metal (Jayasumana et al 2015a(Jayasumana et al , 2015b(Jayasumana et al , 2015c. Chronic lead (Pb) exposure could cause CKDu especially in the presence of other nephrotoxins (Ananda Ananda Jayalal et al 2019;Levine et al 2015;Perera et al 2020). The etiological heavy metal agent, if applicable, still remains inconclusive since several studies indicated that As would not cause CKDu (Ananda Ananda Jayalal et al 2019;Ayala Herath et al 2018;Diyabalanage et al 2017;Nanayakkara et al 2014Wickramarathna et al 2017).…”

Evaluation of Performance of Existing RO Drinking Water Stations in the North Central Province, Sri Lanka

“…Even though Sri Lanka has not been an industrialized country, anthropogenic activities such as agricultural practices and waste disposal strategies have significantly influenced the quality of freshwater bodies in certain areas other than natural and environmental factors. In particular, rural communities in the dry zone of Sri Lanka, which cover two-thirds of the island, have suffered from severe health issues regarding the consumption of groundwater [ 1 , 2 , 3 , 4 ]. The prevalence of CKDu has been a life-threatening crisis for the farming community in the dry zone [ 5 , 6 ].…”