Identification of factors affecting chronic kidney disease of unknown aetiology prevailing in North Central Province of Sri Lanka

The Chronic Kidney Disease of unknown aetiology (CKDu) prevailing in North Central Province (NCP) of Sri Lanka was confined to certain geographical areas and existing literature asserts that the pathogenicity of the disease is multifactorial. Many research outcomes hypothesised the impact of exposure to low concentrations of multiple environmental contaminants, which were the driving force. The risk of disease is correlated with people’s physiological conditions and lifestyle-related factors. However, physiological conditions of people and heavy metal(loid)s exposure through the ingestion pathways have not been adequately examined. It is therefore difficult to confirm if there is a link between the disease prevalence with meta(loid)s ingested via food and other pathways. Consequently, this thesis examines the following: the relationship between Body Mass Index (BMI) and estimated glomerular filtration rate (eGFR) of people living in disease endemic area, health risk assessment for heavy metal(loid)s exposure through ingestion pathways; and spatial variation of heavy metal(loid)s to aid disease prevention programme developments. The results documented that the BMI of participants with eGFR <60 mL/min were lower than BMI of participants with eGFR 60>mL/min. Human health risk assessment of the population in the CKDu endemic area reveals a strong likelihood of severe health outcomes resulting from exposure to Pb. In contrast, nephrotoxic heavy metal(loid)s like Cd and As indicated a low health risk. Comparative study of residents’ dietary intake shows that rice is the main environmental media responsible for heavy metal(loid)s exposure, followed by fish and vegetables. Toxic heavy metal(loid)s exposure through drinking water was minimal. We hypothesise that the low BMI of residents in CKDu endemic areas may have increased their susceptibility to develop CKDu with exposure to multiple environmental contaminations and adverse conditions. Since nephrotoxic heavy metal(loid) exposure is lower than the daily recommended limits, exposure to heavy metals is not the only environmental factor responsible for CKDu development. It can be related to people’s exposure to other multiple factors such as pesticides, dehydration stress, infectious diseases, drinking hard water and higher fluorides intake.