Glyphosate and AMPA of agricultural soil, surface water, groundwater and sediments in areas prevalent with chronic kidney disease of unknown etiology, Sri Lanka

Abstract

Glyphosate, which is commercially available as Roundup®, was the widely used herbicide in Sri Lanka until 2015 and is suspected to be one of the causal factors for Chronic Kidney Disease of unknown etiology (CKDu). This research, therefore, aims at studying the presence of glyphosate and Aminomethylphosphonic acid (AMPA) in different environmental matrices in CKDu prevalent areas. Topsoil samples from agricultural fields, water samples from nearby shallow wells and lakes, and sediment samples from lakes were collected and analyzed for glyphosate and AMPA using the LC/MS. Glyphosate (270-690 µg/kg) and AMPA (2-8 µg/kg) were detected in all soil samples. Amorphous iron oxides and organic matter content of topsoil showed a strong and a moderate positive linear relationship with glyphosate. The glyphosate and inorganic phosphate levels in topsoil had a strong negative significant linear relationship. Presence of high valence cations such as Fe and Al in topsoil resulted in the formation of glyphosate-metal complexes, thus strong retention of glyphosate in soil. Lower levels of AMPA than the corresponding glyphosate levels in topsoil could be attributed to factors such as the strong adsorption capacity of glyphosate to soil and higher LOQ in the quantification of AMPA. The glyphosate levels of lakes were between 28 to 45 µg/L; no AMPA was detected. While trace levels of glyphosate (1-4 µg/L) were detected in all groundwater samples, AMPA (2-11µg/L) was detected only in four out of nine samples. Glyphosate was detected in all sediment samples (85-1000 µg/kg), and a strong linear relationship with the organic matter content was observed. AMPA was detected (1-15 µg/kg) in seven out of nine sediment samples. It could be inferred that the impact on CKDu by the levels of glyphosate and AMPA detected in the study area is marginal when compared with the MCL of the USEPA (700 µg/L).

Environmental exposures in young adults with declining kidney function in a population at risk of Mesoamerican nephropathy

“…Overall, the measured concentrations of pesticide metabolites, suggest exposure to 2,4-D, chlorpyrifos of which TCP is a metabolite; and pyrethroids (such as cypermethrin of which 3-PBA and DCCA are metabolites). Although glyphosate has been proposed to play an important role in the development of CKDu (36), the urinary levels of excreted glyphosate in the present study were below the LOD in the majority of the samples. In contrast to the results from metals, using raw values rather than creatinine adjustment did not substantially alter the differences in pesticide and pesticide metabolite concentrations between the two visits.…”

Determination of Glyphosate in Water from a Rural Locality in México and Its Implications for the Population Based on Water Consumption and Use Habits

“…At the international level, in recent years the presence of glyphosate has been found in both ground and surface water in Canada [ 38 ], Argentina [ 39 ] and Sri Lanka [ 40 ]. The values found are very similar to was found in Tenampulco, except in Argentina, due to the excessive use of glyphosate on crops where genetically modified organisms are planted [ 41 ].…”

Glyphosate’s Synergistic Toxicity in Combination with Other Factors as a Cause of Chronic Kidney Disease of Unknown Origin

“…Another recent study shows glyphosate contamination in CKDu-affected areas [41]: the glyphosate levels of lakes were between 28 and 45 μg /L. Glyphosate was detected in all sediment samples (85–1000 μg/kg), and a strong linear relationship with the organic matter content was observed.…”