Chronic kidney disease of unknown origin (CKDu) has emerged as a serious health issue in rural farming communities across Sri Lanka, El Salvador, Nicaragua and Costa Rica, damaging the health of both the farmers and their fragile economy.

The reason for the disease hasn’t been clear so Dr Rangana Kulathunga, Dr Ayanka Wijayawardena and Laureate Professor Ravi Naidu have been conducting research into possible heavy metal exposure in these communities through contaminated drinking water, rice and vegetables.

Results showed that rice contaminated with lead is the biggest risk to health followed by similarly contaminated inland fish and vegetables. The team also found that potatoes and bitter gourd accumulate lead to a greater extent than other vegetables, whilst carrots accumulate more manganese, copper and zinc than other vegetables.

Whilst the reasons for the increase in these heavy metals and their source is still being investigated, the team have been able to recommend ways the local communities can start reducing the amount of these contaminants that they ingest and hopefully reduce the number of cases of chronic kidney disease. These recommendations include increasing the level of cleaning which happens during the processing of rice for consumption and reducing overall intake of ‘at risk’ vegetables by substituting with alternatives. They have also recommended that periodic monitoring of rice and vegetables is undertaken to check for higher levels of contaminants.

Further work will be undertaken to better understand the contaminants’ journey and their ultimate impact, for example how different varieties of rice accumulate contaminants and whether different parts of the rice plant are more at risk than others.

For more information on this fascinating topic, please contact Dr Ayanka Wijayawardena at