Water quality, microcystin-LR, and Cylindrospermopsin contamination status of spring and dug well water in CKDu high, low, and non-prevalent areas of Sri Lanka

Cyanotoxins, Microcystin LR (MC-LR) and Cylindrospermopsin (CYN) are hepato nephro toxins considered as one of the hypotheses for Chronic Kidney Disease Unknown Etiology (CKDu) in Sri Lanka. Recent studies have revealed that significant number dug wells North Central Uva provinces where CKDu is prevalent contaminated with cyanotoxins MC-LR CYN. In present study, cyanotoxin; MC-LR, CYN, potential toxin-producing cyanobacteria were studied 330 9 spring water samples collected from high areas several Divisional Secretariats (DS) Grama Niladhari (GN) divisions Anuradhapura (Padaviya DS, Medawachchiya Kebithigollewa DS), Polonnaruwa (Medirigiriya Badulla (Girandurukotte GN) Ampara (Dehiaththakandiya DS) districts, low district (Galnewa Rajanganaya non-prevalent Angunakolapelessa DS Hambanthota district. General quality parameters: temperature, pH, conductivity, Dissolved Oxygen (DO), Nitrate (N-NO3-), Nitrite (N-NO2-), Ammonia (N-NH3), Total Phosphorus (TP), Hardness (TH) determined using standard spectrophotometric titrimetric methods. BACON test kits used following manufactures instructions to quantify concentrations by ELISA plate reader. Cyanobacteria density species composition under light microscopy algae keys. With exception Electrical Conductivity, all parameters tested remained within SLSI drinking range. Microcystis spp. cell densities ranged 14±3 1590±256 cells mL-1, concentration ranging 0.04±0.01 3.89±0.02 µg L-1. At different CYN (0.04±0.01 3.59±0.05 L-1), Cylindrospermopsis varied 15 ±4 615±112 mL-1. Well was did not record cyanobacteria. The factor analysis classified well waters into three clusters high, low, non-prevalence presence absence cyanotoxins. contrast, springs a separate cluster. High found 85% Padaviya 80% Medirigiriya respectively. Nitrate-N (3.01±0.56 mg L-1) Nitrite-N (0.69±0.09 recorded prevalence areas. Thus, results study showed relationship between cyanobacteria, records area. Accordingly, further comprehensive needed be carried out confirm Lanka cyanotoxin listed WHO report possible reasons CKDu.