Hydro-epidemiology of Chronic Kidney Disease(CKD) in Sri Lanka and Its Similarities to the CKD Epidemic in Meso-America.Sarath Gunatilake M.D, Dr. P.H, Professor, California State University, Long Beach California

Abstract:

Over 2000 years ago Sri Lanka was known as the granary of the east. This distinction was achieved with a massive rice production aided by an efficient irrigation system. The basic structural unit of this irrigation system -with thousands of man-made lakes- was a large reservoir collecting rain water from tributaries and redistributing it to a cascade of rice paddy farms. The rice cultivation used organic fertilizer and natural pesticides made from ancient Ayurvedic recipes.

The sociopolitical changes initiated in the county in 1977 resulted in a modernized agricultural economy with the renovation of the old irrigation system. Heavy use of pesticides, mostly Glyphosate (brand name "Round Up") with government subsidized cheap synthetic fertilizer (mostly triple phosphate) contaminated with heavy metals, including Arsenic and Cadmium, became a common practice. As a result, the shallow aquifers in the lowest lying areas, recharged by the irrigation water, was contaminated with Calcium, Magnesium phosphates, and the heavy metals, rendering the drinking water from shallow wells in these areas, extremely hard and unpalatable. The practice of drinking water from the shallow wells in low lying areas, most of which are abandoned now, and the use and spraying of pesticides particularly Glyphosate (often without proper personal protective equipment) have been identified in a case control study, as the main risk factors responsible for a massive epidemic of Chronic Kidney Disease (CKD) affecting 450,000 young farmers, resulting in 23,000 deaths. It is hypothesized that the Glyphosate chelates heavy metals delivering it to the kidney, with contaminated drinking water and food, causing progressive kidney damage. The same irrigation system that contributed to past prosperity has now become a scourge within the realm of a modernized agriculture. Climatic variations, global warming and severe dehydration also have been identified as contributory factors. Similar CKD epidemic killing thousands of sugar cane farmers, in Costa Rica, El Salvador and Nicaragua have been documented. The same risk factors (particularly the use of Glyphosate and dehydration) may be at play in these countries but at different levels of intensity.