Phosphate Fertiliser Induced Chronic Kidney Disease

An unknown medical condition has been killing agricultural workers in northern Sri Lanka. The illness is officially described as a 'Chronic Kidney Disease of non-Traditional causes (CKDnT)'.

Patients with CKDnT do not have the commonly known risk factors for kidney disease, such as diabetes and hypertension. Which means that another etiology must be at work here. While northern Sri Lanka is 'blessed' with a hot climate, agricultural workers are not alike the sugar cane workers in Mesoamerica. Chronic dehydration does result in kidney problems and eventually to renal failure.

During the last 2600 years, farmers inhabiting dry zone of Sri Lanka were cultivating rice using irrigated water and organic fertilizer (for our English readers: fertiliser). Now, new varieties of rice cultivated by farmers require large amounts of chemical fertilizers.

Organic or natural fertilizers, such as manure, compost or paddy husk, all contained very low amounts of arsenic. Despite the fact that the import of arsenic containing pesticides is illegal, all tested pesticide brands contained arsenic[1]. There is evidence of a positive association between arsenic exposure and kidney disease mortality[2]. This special type of chronic kidney disease is a toxic nephropathy and arsenic may play a causative role along with a number of other heavy metals. Findings suggest that agrochemicals, especially phosphate fertilizers, are a major source of inorganic arsenic in CKDnT endemic areas in Sri Lanka.

Another possible culprit may be glyphosate (better known as RoundUp), the most widely used herbicide in the disease endemic area and its unique metal chelating properties. While the substance in itself is not considered very toxic to humans, it seems to have acquired the ability to destroy the renal tissues of thousands of farmers when it forms complexes with hard water or nephrotoxic metals[3]. It might even explain similar kidney disease epidemics observed in Andra Pradesh (India) and Central America.

[1] Jayasumana et al: Phosphate fertilizer is a main source of arsenic in areas affected with chronic kidney disease of unknown etiology in Sri Lanka in SpringerPlus - 2015
[2] Zheng et al: Arsenic and Chronic Kidney Disease: A Systematic Review in Current Environmental Health Reports – 2014
[3] Jayasumana et al: Glyphosate, Hard Water and Nephrotoxic Metals: Are They the Culprits Behind the Epidemic of Chronic Kidney Disease of Unknown Etiology in Sri Lanka? in International Journal of Environmental Research and Public Health – 2014