Groundwater Quality Problems and Issues in the Dry-Zone of Sri Lanka with Special Reference to Fluoride Contamination and the Chronic Kidney Disease

摘要

A 2004 estimate shows that nearly 70% of the population in Sri Lanka, 22.4% urban population and 71.8% rural population rely on groundwater for their domestic water requirements. Most of these groundwater sources are thought not safe enough to guarantee total protection against diseases. Therefore few year back the Government of Sri Lanka took a policy decision to increase the investment on water supply to achieve nearly 100% safe drinking water coverage by the 2025. However, looking at the present situation, the safe drinking water target seems to have reached far short results than expected as the number of water related health problems are on the increase especially in the dry zone of Sri Lanka. Analyzing over 1,000 wells used as water sources, it was found out that groundwater quality in the dry zone of Sri Lanka shows contamination from fluoride, iron, hardness and chlorides. Fluoride levels as high as 3,132 mg/1 was observed. Almost one fourth of wells in the districts of Anuradhapura, Polonnaruwa, Puttalam and Vauniya had fluoride levels unsafe for human consumption. Over 33.8% of wells in Anuradhapura and over 63% of wells in Puttalam had iron contents above 1 mg/1. The hardness problem was most serious in the Puttalam district where total hardness as high as 15,800 mg/1 is reported. 25% of the wells in Puttalam had hardness above 600 mg/1. Initial investigations comparing the basic groundwater quality parameters in high CKD risk areas with water quality of the safe areas does not show much differences. However it is too early to make any conclusions from this study as it is continuing.