Gunarathna Shankani, Gunawardana Buddhika, Jayaweera Mahesh, Manatunge Jagath, Zoysa Kasun
a Department of Civil Engineering , University of Moratuwa , Moratuwa , Sri Lanka.
J Environ Sci Health B. 2018;53(11):729-737. doi: 10.1080/03601234.2018.1480157. Epub 2018 Jun 8.
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).
草甘膦以“农达”®的商品名上市销售，在2015年之前一直是斯里兰卡广泛使用的除草剂，并且被怀疑是病因不明的慢性肾脏病（CKDu）的致病因素之一。因此，本研究旨在调查CKDu流行地区不同环境基质中草甘膦和氨甲基膦酸（AMPA）的存在情况。采集了农田的表层土壤样本、附近浅井和湖泊的水样以及湖泊的沉积物样本，并使用液相色谱/质谱联用仪（LC/MS）分析其中的草甘膦和AMPA。在所有土壤样本中均检测到了草甘膦（270 - 690微克/千克）和AMPA（2 - 8微克/千克）。表层土壤中的无定形氧化铁和有机质含量与草甘膦呈现出强线性正相关和中等线性正相关关系。表层土壤中的草甘膦和无机磷酸盐水平呈现出强线性负相关关系。表层土壤中高价阳离子（如铁和铝）的存在导致形成了草甘膦 - 金属络合物，从而使草甘膦在土壤中强烈保留。表层土壤中AMPA的含量低于相应的草甘膦含量，这可能归因于草甘膦对土壤的强吸附能力以及AMPA定量分析中较高的定量限等因素。湖泊中的草甘膦含量在28至45微克/升之间；未检测到AMPA。虽然在所有地下水样本中均检测到痕量草甘膦（1 - 4微克/升），但在九个样本中只有四个检测到了AMPA（2 - 11微克/升）。在所有沉积物样本中均检测到了草甘膦（85 - 1000微克/千克），并且观察到其与有机质含量存在强线性关系。在九个沉积物样本中有七个检测到了AMPA（1 - 15微克/千克）。可以推断，与美国环境保护局（USEPA）的最大污染物浓度（MCL，700微克/升）相比，研究区域内检测到的草甘膦和AMPA水平对CKDu的影响微乎其微。
