Kidney Disease Of Unknown Etiology Research Articles

Chronic Kidney Disease of Unknown Etiology: Case Definition for India - A Perspective.

Chronic kidney disease of unknown etiology (CKDu) is a form of chronic kidney disease (CKD) that is prevalent in certain rural populations around the world. It is distinct by its clinicopathologic characteristics and has multifactorial etiology, being mostly linked to several environmental toxins. Although the presentation is similar in various regions across the globe, it also differs in subtle ways from region to region. In India too, there have been reports of the disease in several pockets. There is a need for a comprehensive definition to identify the cases accurately to ease clinical diagnosis and facilitate screening of populations in affected areas. This article presents the diagnostic criteria for CKDu proposed in a consensus meeting at Chennai, India, in May 2017.

Increase of core temperature affected the progression of kidney injury by repeated heat stress exposure.

An epidemic of chronic kidney disease of unknown etiology (Mesoamerican nephropathy) has emerged in hot regions of Central America. We have demonstrated that dehydration associated with recurrent heat exposure causes chronic kidney disease in animal models. However, the independent influence of core body temperature on kidney injury has not been explored. In the present study, we tested the hypothesis that kidney injury could be accelerated by increasing body temperature independent of external temperature. Wild-type mice were exposed to heat (39.5°C, 30 min, 2 times daily) with or without the mitochondrial uncoupling agent 2,4-dinitrophenol (DNP) for 10 days. Core temperature, renal function, proteinuria, and renal histological and biochemical analyses were performed. Isolated mitochondria markers of oxidative stress were evaluated from kidney tissue. DNP increased body core temperature in response to heat by 1°C (42 vs. 41°C), which was transient. The mild increase in temperature correlated with worsening albuminuria (R = 0.715, P < 001), renal tubular injury, and interstitial infiltration of monocytes/macrophages. Tubular injury was marked in the outer medulla. This was associated with a reduction in kidney tissue ATP levels (nonheated control: 16.71 ± 1.33 nmol/mg and DNP + heat: 13.08 ± 1.12 nmol/mg, P < 0.01), reduced mitochondria, and evidence for mitochondrial oxidative stress. The results of the present study suggest that kidney injury in heat stress is markedly worsened by increasing core temperature. This is consistent with the hypothesis that clinical and subclinical heat stroke may play a role in Mesoamerican nephropathy.

Exposure to Hantavirus is a Risk Factor Associated with Kidney Diseases in Sri Lanka: A Cross Sectional Study.

Chronic kidney disease of unknown etiology (CKDu) imposes a substantial burden on public health in Sri Lankan agricultural communities. High seroprevalences of hantavirus have been reported in CKDu patients in several locations of Sri Lanka. We carried out a cross-sectional study followed by an unmatched case-control comparison in two geographically distinct areas of Sri Lanka, Girandurukotte (CKDu endemic) and Kandy (CKDu non-endemic) to determine whether exposure to hantaviruses is a potential risk factor in patients with kidney disease. An indirect immunofluorescent antibody assay using two antigens, Thailand orthohantavirus-infected and recombinant N protein-expressing Vero E6 cells, were used for serodiagnosis. Participants’ demographic and other socio-economic data were collected through a structured questionnaire. Fifty kidney disease patients and 270 controls from Kandy and 104 kidney disease patients and 242 controls from Girandurukotte were examined. Seropositivities were 50% and 17.4% in kidney patients and controls, respectively, in Girandurukotte, and they were 18% and 7% in Kandy. The odds of exposure to hantaviruses were higher for kidney disease patients than for controls in both Girandurukotte (OR:3.66, 95% CI:2.01 to 6.64) and Kandy (OR:2.64, 95% CI:1.07 to 6.54) in binary logistic regression models. According to statistical analysis, individuals exposed to hantaviruses had a higher risk of developing renal impairment. Therefore, hantavirus infection might be an important risk factor for development of kidney disease in Sri Lanka.

Glyphosate's Synergistic Toxicity in Combination with Other Factors as a Cause of Chronic Kidney Disease of Unknown Origin.

Chronic kidney disease of unknown etiology (CKDu) is a global epidemic. Sri Lanka has experienced a doubling of the disease every 4 or 5 years since it was first identified in the North Central province in the mid-1990s. The disease primarily affects people in agricultural regions who are missing the commonly known risk factors for CKD. Sri Lanka is not alone: health workers have reported prevalence of CKDu in Mexico, Nicaragua, El Salvador, and the state of Andhra Pradesh in India. A global search for the cause of CKDu has not identified a single factor, but rather many factors that may contribute to the etiology of the disease. Some of these factors include heat stroke leading to dehydration, toxic metals such as cadmium and arsenic, fluoride, low selenium, toxigenic cyanobacteria, nutritionally deficient diet and mycotoxins from mold exposure. Furthermore, exposure to agrichemicals, particularly glyphosate and paraquat, are likely compounding factors, and may be the primary factors. Here, we argue that glyphosate in particular is working synergistically with most of the other factors to increase toxic effects. We propose, further, that glyphosate causes insidious harm through its action as an amino acid analogue of glycine, and that this interferes with natural protective mechanisms against other exposures. Glyphosate’s synergistic health effects in combination with exposure to other pollutants, in particular paraquat, and physical labor in the ubiquitous high temperatures of lowland tropical regions, could result in renal damage consistent with CKDu in Sri Lanka.

Serological Evidence of Thailand Orthohantavirus or Antigenically Related Virus Infection Among Rodents in a Chronic Kidney Disease of Unknown Etiology Endemic Area, Girandurukotte, Sri Lanka.

We have reported high seroprevalence to Thailand orthohantavirus (THAIV) or THAIV-related orthohantavirus (TRHV) among patients with chronic kidney disease of unknown etiology in Girandurukotte, Sri Lanka. THAIV or TRHV infection is considered to be transmitted by rodent hosts in this area, but its reservoir rodents have not yet been identified. Hence, 116 rodents were captured, and seroprevalences were examined by indirect immunofluorescent antibody assay (immunofluorescence assay [IFA]) using antigens of THAIV strain Thai749-infected Vero E6 cells and recombinant nucleocapsid protein of THAIV expressed in Vero E6 cell. Molecular biological species identification of rodents was carried out by sequencing rag1, irbp, and mitochondrial cytb genes. The majority (112/116) of the captured rodents were lineage Ib of black rats (Rattus rattus). Among them, 19.6% (22/112) of the rats possessed antibodies against THAIV. Also, a lesser bandicoot rat (Bandicota bengalensis), which belongs to the Sri Lankan endemic genetic lineage, was seropositive (1/1). Two Mus booduga and one Murinae sp. were seronegative. Rodent sera showed less cross-reactivities to antigens of Vero E6 cells infected with Hantaan orthohantavirus (HTNV), Seoul orthohantavirus (SEOV), and Puumala orthohantavirus (PUUV) in IFA. These results suggest that the hantavirus present in rodents in Sri Lanka is related to THAIV or TRHV rather than to SEOV, HTNV, or PUUV. However, it might be serologically distinct from the prototype THAIV strain, Thai749, used in this study. This study revealed that black rats and lesser bandicoot rats belonging to Sri Lankan endemic lineages are possible reservoirs for THAIV or TRHV in Girandurukotte. Further multiple geographical studies are needed to confirm the THAIV or TRHV reservoir status of black and lesser bandicoot rats in Sri Lanka.

Defluoridation of calcium-rich groundwater using iron oxide nanoparticles

Abstract It has been suggested that moderate to high fluoride ion concentrations in the presence of calcium in groundwater can represent human health hazards resulting in possible lesions in tubular cells, leading to chronic kidney disease of unknown etiology (CKDu). This study focuses on fluoride removal in the presence of calcium using iron oxide nanoparticles (FeONs) as an effective adsorbent in single- and multi-solute batch-studies. Fluoride and calcium removal by FeONs in single-solute batch-studies occurred only by adsorption. Both species followed the Langmuir isotherm model and pseudo second-order kinetics, indicating monolayer adsorption and chemisorption, respectively. In multi-solute batch-studies, fluoride removal was attributed to adsorption and chemical precipitation forming CaF2 in almost similar magnitude. For calcium removal in multi-solute studies, adsorption, co-precipitation, and precipitation were the prominent mechanisms, with co-precipitation dominant. Thus, FeONs are effective in fluoride removal by adsorption in both the presence and absence of calcium. FeONs could also be used successfully year-round in tropical climates, where calcium levels vary substantially, to lessen the risk of CKDu.

Searching for CKDu: Mystery kidney disease, differentiated (in)visibility, and contingent geographies of care in dry zone Sri Lanka

In Sri Lanka's dry zone, an epidemic of Chronic Kidney Disease of Unknown Etiology (CKDu) has evaded scientific explanation for more than two decades. Unsurprisingly, the search for CKDu's cause has become the focus of intense study. Comparatively, less is known about local attempts to neutralize biomedical uncertainty within disease “hotspots” or how this creates new contingent geographies of care. As a consequence, I examine what is at stake in the label CKDu and how these stakes, and indeed the visibility of the mystery disease itself, varies across scale and space. I argue that despite the hypervisibility of mystery kidney disease in news media, existing clinical practices within disease hotspots cannot actually differentiate between CKDu and regular chronic kidney disease (CKD). As a consequence, distinctions between categories of illness routinely collapse in everyday life. And yet, evidence collected over 15 months of ethnographic fieldwork reveals that other types of difference profoundly shape access to care in the dry zone. Specifically, I demonstrate that it is not a diagnosis of CKDu but residence in areas designated as disease “hotspots” that determines access state-sponsored kidney disease stipends. In short, I suggest that some experiences of kidney disease are more visible than others and this often has much more to do with where these cases are than with what may have caused them. As a consequence, the article concludes that CKDu has produced new forms of difference in the dry zone, but that the main axis of differentiation is more geographical than biophysical.

Investigating Possible Infectious Causes of Chronic Kidney Disease of Unknown Etiology in a Nicaraguan Mining Community.

.A chronic kidney disease of unknown etiology (CKDu) has been killing workers in Central America. Occupational heat stress is thought to play an important role. Leptospirosis and hantavirus have been suggested as additional possible risk factors. In a case–control study in a Nicaraguan mining community, a structured survey was administered to adults, and biological measurements and specimens were taken. Serum was analyzed for antibodies to Leptospira and hantavirus. Before statistical analysis, a board-certified nephrologist determined final case and control status based on serum creatinine and other laboratory values. Multivariable analysis was by logistic regression. In sensitivity analyses, cases were restricted to those diagnosed with CKDu in the previous 3 years. Of 320 eligible participants, 112 were classified as presumptive cases, 176 as controls and 32 as indeterminant. The risk of CKDu in those ever having worked in mining or construction was 4.4 times higher than in other participants (odds ratio = 4.44, 95% CI: 1.96–10.0, P = 0.0003). Eighty-three (26%) of the 320 participants were seropositive for at least one tested strain of Leptospira. No evidence of a causal link between leptospirosis or hantavirus and CKDu was found. The sensitivity analyses provide some evidence against the hypotheses that leptospirosis or hantavirus leads to CKDu within a few years. A major limitation was the impossibility of determining the absolute or relative timing of infection and CKDu onset. A prospective cohort design, with repeated collection of specimens over several years, could yield clearer answers about infections as potential etiologic agents in CKDu.

SAT-208 High prevalence of chronic kidney disease among Cocoa Farmers in Cameroon, a possible contribution of Chronic Kidney Disease of Unknown Aetiology (CKDu)

Data on the burden of chronic kidney disease(CKD) in agricultural workers has largely been derived from sugarcane and rice farmers in Central America and South-East Asia; with an ill-defined form of chronic interstitial nephritis known as chronic kidney disease of unknown etiology(CKDu) accounting for most cases. There is sparse data on CKD in agricultural workers in tropical regions of sub-Saharan Africa where farming constitutes a major occupation and cocoa is a major cash crop. Cocoa grows preferentially in hot tropical climate thus exposing the farmers to heat stress.

SUN-328 ADENINE PHOSPHORIBOSYLTRANSFERASE DEFICIENCY: A POTENTIALLY REVERSIBLE CAUSE OF CHRONIC KIDNEY DISEASE IN THE PRE AND POST TRANSPLANT SETTING

Adenine phosphoribosyltransferase (APRT) deficiency is a rare, autosomal recessive disorder which results in increased production of 2,8-dihydroxyadenine (DHA) viathe purine salvage pathway. Excess DHA is excreted in the urine, where it forms highly insoluble crystals and manifests as either urolithiasis or crystalline nephropathy. The onset and presentation of disease is variable and may present as chronic kidney disease of unknown aetiology; renal calculi; misdiagnosed oxalate nephropathy; graft dysfunction following renal transplantation; or through family screening. DHA crystals have distinct appearance on renal biopsy and urine microscopy, but is easily misdiagnosed or unrecognized due to low clinical suspicion. Diagnosis is of paramount importance; as chronic renal injury can be potentially can be minimized with xanthine oxidase inhibitors (allopurinol or feboxustat). We present cases of 3 cases of APRT deficiency (2 patients were post cadevaric renal transplantation). Patient characteristics pre and post transplantation will be presented in a table, including information on renal function, oxipurinol levels and urine microscopy. Indication and protocol transplant renal biopsies were processed as standard protocol and evaluated for rejection (according to Banff criteria) and crystal nephropathy (percentage of biopsy affected and distribution in luminal, epithelial and interstitial compartments). Both transplant patients had early recurrence of crystalline nephropathy (figure 1) and necessitated rapid escalation of xanthine oxidase inhibitors to levels exceeding recommendations for renal impairment. Both patients were also treated for borderline rejection and this highlights the difficulties in delineating rejection from crystal-associated inflammation. One patient developed Banff 2A rejection but both patients suffered infective complications of excess immunosuppression. Review of all available transplant biopsies revealed interesting kinetics of crystal formation and deposition in the kidney. Early in the disease, with maximal excretion of DHA metabolites in urine leads to crystal precipitation, luminal aggregate with tubular obstruction and injury. These crystals then are seen in the epithelial layer (either by encapsulation or endocytosis). Later in the disease, there is associated tubular rupture and interstitial deposition with associated interstitial fibrosis and tubular atrophy (figure 2). The amount of luminal crystals reduce over time with increasing dose of allopurinol and/or feboxustat. Lack of awareness and clinical suspicion appear to be a major barrier to timely diagnosis, although multiple management challenges post diagnosis remains. The current target levels and biomarkers of adequacy of therapy with allopurinol and/or feboxustat remains to be determined.

SUN-201 GENOME WIDE ANALYSIS STUDY TO EVALUATE POTENTIAL GENETIC RISKS AND IMMUNOLOGICAL PATHWAYS ASSOCIATED WITH CHRONIC KIDNEY DISEASE OF UNKNOWN ETIOLOGY

Chronic kidney disease of unknown etiology (CKDu) has been studied on the light of its etiology and pathogenesis, mostly on possible involvement of environmental factors. Earlier inconsistent data on involvement of different heavy metals has been suggested along with plausible roles of herbicides, mycotoxins, pesticides, and algal toxins with CKDu. The present study is proposed to identify exact cause(s) of CKDu and complex involvement of genetic and environmental factors.This study has evaluated the potential candidate genes associated with CKDu through a genome wide analysis study (GWAS

SUN-236 GEOGRAPHICAL DISTRIBUTION OF “UNCERTAIN” RENAL DISEASE DIAGNOSES IN RENAL SPECIALITY PRACTICES OF SOUTH-EAST QUEENSLAND AND DARLING DOWNS, AUSTRALIA.

Chronic kidney disease of unknown aetiology (CKDu) describes CKD that is not attributable to traditional, known, risk factors. Since early 2000s, CKDu frequency has been reported as increasing globally but especially in developing countries. CKDu has received little attention in developed countries. This study aimed to identify geographical foci of renal disease diagnoses (Dx) in South East Queensland (SEQ) and the Darling Downs (DD), Australia, attributed to an “Uncertain” Dx where the treating clinician is uncertain of the primary renal disease.

SAT-230 OCCUPATIONAL HERBICIDE EXPOSURE AND DECLINING KIDNEY FUNCTIONS AMONG SUGARCANE FARMERS IN RURAL SRI LANKA.

Paraquat and Glyphosate were leading herbicides among Sugarcane Farmers (SF) hence occupational exposure is inevitable. These have been recently linked with the development of Chronic Kidney Disease of unknown aetiology (CKDu). Urinary KIM-1 and NGAL are good predictors of renal injury prior to detectable changes in serum creatinine and served as potential biomarkers in predicting tubulointerstitial damage. Although KIM-1 and NGAL are suggested to be useful biomarkers in determining kidney injury in rural Sri Lankan paddy farmers, no simultaneous studies have so far measured frequently used herbicides and their association with renal biomarkers.

A Review of Chronic Kidney Disease of Unknown Etiology in Sri Lanka, 2001-2015.

An increase in the prevalence of chronic kidney disease of unknown etiology (CKDu) was observed in several countries of the world since the early 2000s. We reviewed the literature to summarize the existing knowledge regarding epidemiology, clinical features, and risk factors for CKDu in Sri Lanka. We reviewed published literature from PubMed and unpublished literature from literature repository of CKDu published by the World Health Organization. We identified 36 articles based on various inclusion/exclusion criteria and reviewed the full text of all selected articles. The prevalence of CKDu was approximately 5% in endemic areas based on the surveillance data. CKDu accounted for 70% of CKD cases in endemic areas. Clustering of cases was observed in select divisions and districts in the dry region of the country. Low body mass index, normal blood pressure, scanty proteinuria, and tubulointerstitial pathology were characteristics of early stages of a disease. Genetic susceptibility, farmer as occupation, heavy metals (cadmium and arsenic), and drinking well water were identified as risk factors. Data were limited on the association with agrochemical use and heat stress/dehydration. Community- and facility-based surveillance needs to be strengthened to document the burden of disease and trends over time.

TO STUDY THE ETIOLOGICAL PROFILE IN CHRONIC KIDNEY DISEASE PATIENTS

Background: Chronic Kidney Disease (CKD) is determined by the presence of kidney injury and by the level of renal function, assessed according to the glomerular filtration rate.&#x0D; Methods: This observational case study will be conducted among patients of newly diagnosedor known cases of chronic kidney disease admitted or attending outdoor clinic at Mahatma Gandhi Hospital Jodhpur.&#x0D; Results: Twenty three patients out of 75 were diabetic, 19 patients had chronic kidney disease of unknown etiology and 12 had both DM and HTN, only one patient had CKD because of RCC.&#x0D; Conclusion: Most common etiologies of CKD patients on hemodialysis are Diabetic nephropathy.&#x0D; Keywords: Chronic Kidney Disease (CKD), Hypertension, Diabetes.

Prevalence and risk factors for impaired kidney function in the district of Anuradhapura, Sri Lanka: a cross-sectional population-representative survey in those at risk of chronic kidney disease of unknown aetiology

BackgroundOver the last 20 years there have been reports of a form of chronic kidney disease of unknown cause (CKDu) affecting rural communities in the North Central Province of Sri Lanka. Valid prevalence estimates, using a standardised methodology, are needed to assess the burden of disease, assess secular trends, and perform international comparisons.MethodsWe conducted a cross-sectional representative population survey in five study areas with different expected prevalences of CKDu. We used a proxy definition of CKDu involving a single measure of impaired kidney function (eGFR< 60 mL/min/1.7m2, using the CKD-Epi formula) in the absence of hypertension, diabetes or heavy proteinuria.ResultsA total of 4803 participants (88.7%) took part in the study and 202 (6.0%; 95% CI 5.2–6.8) had a low eGFR in the absence of hypertension, diabetes and heavy proteinuria and hence met the criteria for proxy CKDu. The proportion of males (11.2%; 95% CI 9.2–13.1) were triple than the females (3.7%; 95% CI 2.9–4.5). Advancing age and history of CKD among parents or siblings were risk factors for low GFR among both males and females while smoking was found to be a risk factor among males.ConclusionsThese data, collected using a standardised methodology demonstrate a high prevalence of impaired kidney function, not due to known causes of kidney disease, in the selected study areas of the Anuradhapura district of Sri Lanka. The aetiology of CKDu in Sri Lanka remains unclear and there is a need for longitudinal studies to describe the natural history and to better characterise risk factors for the decline in kidney function.

Use of CaO Loaded Mesoporous Alumina for Defluoridation of Potable Groundwater Containing Elevated Calcium Levels

Defluoridation in the presence of high calcium levels in potable groundwater is paramount, as the consumption of groundwater enriched with fluoride, and calcium has been implicated in causing chronic kidney disease of unknown etiology (CKDu) in Sri Lanka. CaO loaded mesoporous alumina (COMA) offers a great potential for defluoridation of potable water, but the effectiveness of COMA in the presence of calcium has not been investigated. This study, therefore, focuses on the investigation of the suitability of COMA for the defluoridation of potable water with high calcium levels. Mesoporous alumina was successfully functionalized with CaO to synthesize nano-level COMA with an optimum dosage for defluoridation being 2 g L−1. The amount of fluoride adsorbed increased (2.4–19.5 mg g−1) with the increase of the initial fluoride concentration (5–40 mg L−1), and the residual fluoride levels (0.8–1.47 mg L−1) were within the range specified by the WHO for drinking water. The amount of fluoride adsorbed by COMA varied between 6.50 and 7.97 mg g−1 with initial calcium levels between 0 and 1500 mg L−1, indicating that defluoridation was effective in the presence of high calcium levels. The fluoride adsorption was best fitted with the Langmuir model with a maximum monolayer capacity of COMA being 17.83 mg g−1, and adsorption kinetics fitted with the pseudo-2nd order model indicating strong covalent bonding by way of chemisorption. Thus, COMA can be effectively utilized as an adsorbent material in defluoridation efforts in areas prevalent with CKDu in the presence of high fluoride (15 mg L−1) and calcium (1500 mg L−1) levels.

The presence of dehydration in paddy farmers in an area with chronic kidney disease of unknown aetiology.

Kidney disease of unknown aetiology (CKDu) has been a health problem in the rural farming community of the North Central province of Sri Lanka since the 1990s and various environmental factors have been postulated as contributing factors for this disease. The aim of our study was to find out whether farmers undergo dehydration which would lead to concentration of urine and the water soluble potentially toxic substance in the kidney, leading to damage of the renal tubules. Therefore, we studied a sample of healthy farmers who were CKDu-free to determine whether they were dehydrated. Sample included healthy male paddy farmers of Padaviya in the Anuradhapura district. Plasma and urine osmolarity were recorded upon waking up in the morning and evening during the non-farming and farming seasons. Basic statistics and a 2 × 2 anova was done to test the interaction of time of day with farming activity. Farmers were dehydrated according to the plasma osmolarity especially in the mornings, irrespective of whether they were farming or not. Approximately 40% of the sample also demonstrated acute dehydration at the end of the day due to farming activity as indicated by both plasma and urine osmolarity and specific gravity. This study revealed that the farmers of the Padaviya area were either dehydrated or at the upper limit of euhydration sometime during the day irrespective of their activities during the day.

Seven-layer and Two-layer Domestic Filters for the Removal of Nephrotoxic Constituents in CKDu prevalent Areas, Sri Lanka: Are these Viable Options?

Consumption of water with nephrotoxic constituents is said to have caused the chronic kidney disease of unknown etiology (CKDu) in Sri Lanka; hence removal of such constituents from potable water has received profound attention. Although seven-layer and two-layer filters have been introduced to the communities in the CKDu prevalent areas, the efficacy of such filters for removal of nephrotoxic constituents has not been adequately evaluated. This study investigates the efficacy of these two filters for improving drinking water quality in the presence of hardness, fluoride, aluminum, and cadmium. Feed water was synthesized with 353, 143 mgL -1 hardness, 1.7, 0.9 mgL -1 fluoride, 1.2, 1.3 mgL -1 aluminum and 1.1, 1.0 mgL -1 cadmium for seven-layer filter and 342, 149 mgL -1 hardness, 1.7, 0.8 mgL -1 fluoride, 1.5, 1 mgL -1 aluminum and 1.1, 1.2 mgL -1 cadmium for two-layer filter simulating wet (October, November) and extremely wet (December) seasons, respectively. Filtered water with the seven-layer filter contained 336, 146 mgL -1 hardness, 1.8, 1.0 mgL -1 fluoride, 0.7, 0.9 mgL -1 aluminum, and 0.9, 0.99 mgL -1 cadmium after 60- and 30-days of operation under wet and extreme wet seasons, respectively. Filtered water with the two-layer filter showed 332, 149 mgL -1 hardness, 0.6, 1.4 mgL -1 fluoride, 0.7, 0.3 mgL -1 aluminum, and 0.5, 0.2 mgL -1 cadmium after 60- and 30- day operation under wet and extreme wet seasons, respectively. The quality of the filtered water from both filters did not comply with the Sri Lanka Standards (SLS) drinking water quality guidelines. The XRD, FT-IR, ESEM-EDX analyses revealed the presence of calcium, magnesium, fluoride, and aluminum in various layers of filter media of both filters. Such constituents retained in the filter media leached out during filtration resulting in higher levels in the permeate. Hence, the use of seven-layer and two-layer filters does not seem to be a promising solution to remove nephrotoxic constituents present in water in CKDu prevalent areas.

Assessment of Groundwater Quality in CKDu Affected Areas of Sri Lanka: Implications for Drinking Water Treatment.

This study investigated the water quality of the groundwater that was collected from the chronic kidney disease of unknown etiology (CKDu) prevailing areas in the dry zone of Sri Lanka to assess its suitability for drinking purposes, and for the first time a Water Quality Index (WQI) with emphasis on proposing appropriate drinking water treatment method was developed. A total of 88 groundwater samples were collected in dry (December 2016) and wet (May 2017) seasons; high concentrations of water hardness, fluoride, salinity, dissolved organic carbon (DOC), and the general alkaline nature of water were the main issues that were observed for disease incidence. The chemical weathering of the underlying bedrock, followed by ion exchange and precipitation processes, primarily controlled groundwater geochemistry. During the 1985–2017 period, the variations of the annual rainfall and temperature were minimal, which suggests no evidence for major climatic changes within the study areas. Almost all of the samples from the CKDu regions show a low alkali hazard and most of the samples show a medium to high salinity hazard. The DOC of the studied samples was mainly composed of the organic fractions in the following order, as fulvic acids > humic acids > aromatic protein II > soluble microbial by-products, and the molecular weights (MW) of these fractions ranged from 100–3000 Da. Based on the water quality index (WQI) calculations, it was found that only 3.8% in the wet season and 2.6% in the dry season of total water samples were categorized as the “excellent” type, and all other water sources require a further treatment before consumption. As there is an urgent need for establishing proper long-term drinking water treatment technology for the CKDu affected area, these findings can be used as benchmark of raw water quality in the design processes of treatment plants.