Mémoire
| Résumé : | Heavy metals (HMs) and poor water quality are frequently reported as causative factors of Chronic Kidney Disease of unknown aetiology (CKDu) in Sri Lanka. Excessive use of agrochemicals in paddy farming has been pointed to be the main source of these HMs inputs. The main goal of this research was to establish pollution profiles of upland tributaries in order to create a baseline database that will be useful in national water quality management and associated policy enforcement. Measurements of Arsenic (As), Cadmium (Cd), Lead (Pb) and Mercury (Hg) were carried out along three major rivers commonly used for water supply: Mahaweli Ganga, Deduru Oya and Gin Ganga. A land use classification wasalso achieved to locate pollution sources. Our study revealed that despite the presence of HMs, no river exceeded safety limits. According to pollution profiles, As level increased from the source to the mouth. A positive trend was observed between As concentration and agricultural lands expansion while it was lower where forest cover has been preserved. It appears that HMs concentration is due to human activities in upper catchment of selected rivers and not the result of natural contamination. We support that cumulative factors, as dietary habits and regular dehydration, in addition with low contaminated water consumption could be the cause of CKDu. Therefore, we recommend to communities livingin CKDu prevalence to emphasise supply point close the source. Reduction of agrochemicals combine with prevention campaigns are also prescribed to reduce efficiently CKDu occurrence and allow further depollution of contaminated soils and sediments. |
