Sri Lanka is characterized by well-demarcated climatic zones based on the rainfall pattern known as wet zone, dry zone and intermediate zone. Groundwaters in these three zones are extracted mainly for drinking and irrigation from metamorphic hard rock aquifers and saprolite developed on metamorphic rocks. Detailed hydrogeochemical investigations were carried out covering these three climatic zones in order to characterize the groundwater. A total of 166 groundwater samples were collected representing three climatic zones and analyzed for their major and trace element geochemistry. The results indicate a clear difference in the geochemistry of groundwater between climatic regions, whereas semiarid dry zone groundwater is characterized with higher dissolved mineral contents compared that of the wet and intermediate zones.Low pH levels were noticed in the wet zone areas, while high calcium and fluoride contents were observed in the dry and intermediate terrains. Remarkably, high phosphate contents were observed in all three regions, indicating the influence of fertilizer application on groundwater. Particularly in the dry zone regions, the groundwater chemistry is mainly controlled by rock-water interactions and ion exchange processes in which high mineral contents are added from underlying metamorphic rocks to the drinking and irrigation water. The results indicate that groundwater in the dry zone area is under stress compared to other climate areas, but in the wet zone groundwater shows remarkable influence of anthropogenic activities.

In this article, the current scientific evidence of Chronic Kidney disease with unknown aetiology (CKDu), were critically reviewed and harnessed with other relevant literature with a view to justify the possible causative reason(s) for this chronic health problem. To this end, authors first reviewed the literature on socioeconomic , environmental, meteorological, health and geo-environmental/chemical aspects in relation to the CKD of unknown aetiology in Sri Lanka and then studied the known aetiology of CKD (key medical facts) in detail highlighting a comprehensive list of causes. Based on the nature of economic development in the CKDu prevailing area, previous studies have suggested that the causative factor for CKDu is probably environmental and is related to the nature of anthropogenic activities. Therefore, authors investigated subject more into the chronic exposure to heavy metals associated with agricultural activities. Potential sources of heavy metals in the area are mentioned. The geochemical mobility and health effects of three selected elements namely arsenic (As), cadmium (Cd) and Lead (Pb) are studied in detail. The current scientific observations reported on CKD were evaluated with established chemical, geochemical, and health risk of As, Cd and Pb. According to the review, it can be justified that CKDu of the North Central Province (NCP) in Sri Lanka is a decease caused by the chronic exposure and cumulative effects of elevated levels of heavy metals associated with agricultural activities.

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