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Item Method development for the investigation of pesticide residues in soil and heavy metal contamination in pesticides in selected Chronic Kidney Disease of unknown etiology (CKDu) affected areas in Medawachchiya(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Mohotti, N. De. S.; De Silva, R. C. L.Chronic Kidney Disease of unknown etiology (CKDu) has become one of the major public health problems in the North Central Province in Sri Lanka. There is a major concern that the agrochemicals could contribute to CKDu because North Central Province is an agricultural area where agrochemicals have been used for a prolonged period of time. Pesticides could affect the environment either by remaining in the environment as their residues or as a source of heavy metals in the environment. The purpose of this research is to optimize a method for the qualitative analysis of pesticide residues in soil. Puhudivula grama niladhari division which is an area with a high recorded number of CKDu patients in Medawachchiya was selected as the sampling area. Five representative soil samples each from six paddy fields were collected for the study. This study includes qualitative soil analysis of selected pesticide residues such as Profenofos, Diazinon and Imidacloprid, which are the most commonly used paddy field pesticides in Medawachchiya. The presence of these pesticide residues in agricultural soil were analyzed by a Soxhlet extraction method followed by High-Performance Liquid Chromatography (HPLC) and method optimization was carried out according to the matrix. Pesticide residues were absent or below the detection limits. Further studies are required to minimize the background interference from matrix and LC- MS studies are required for the quantification of the residues. The study also includes quantification of heavy metals such as Pb, Cd, Cr and Cu in pesticides by the flame atomic absorption spectroscopy (FAAS). Both commercially available solid pesticides such as Nativo, Mancozeb and liquid pesticides such as Greenup, Profenofos obtained from Medawachchiya area were used for this analysis. When it comes to solid pesticides, Mancozeb showed the highest Pb, Cd, Cr and Cu concentrations as 5.163 ± 0.283 mg/kg, 7.329 ± 0.038 mg/kg, 2.963 ± 0.207 mg/kg, 4.246 ± 1.706 mg/kg respectively. The method recovery values of the quantification of heavy metals in solid pesticides were above 70.00%. From liquid pesticides, Profenofos showed the highest Pb, Cd, Cr and Cu concentrations as 1.533 ± 0.160 mg/L, 1.357 ± 0.040 mg/L, 6.909 ± 0.657 mg/L, 4.905 ± 0.465 mg/L respectively and the method recovery values for the quantification of heavy metals in liquid pesticides were very low with values below 50.00%. Limit of detection and limit of quantification studies proved that all the values were within the detectable limits.Item Presence of arsenic in agrochemicals and their association with the agricultural chronic kidney disease in Sri Lanka(The Journal of Toxicology and Health, 2014) Jayasumana, C.; Fonseka, S.; Fernando, A.; Jayalath, K.; Amarasinghe, M.; Paranagama, P.Chronic Kidney Disease of Agricultural origin (CKDa) formerly known as Chronic Kideny Disease of unknown etiology (CKDu) is one of the biggest health problems in Sri Lanka. In recent years, a significant increase in CKDa cases have been observed in North Central Province (NCP) in Sri Lanka. Since majority of CKDa patients are farmers with chronic arsenic toxicity, the present study was aimed to assess the source of the arsenic in CKDa patients in selected rice farming areas, Padaviya, Mahawilachchiya and Polpithigama and evaluate the amounts of arsenic present in agrochemicals used by these farmers. This study was concentrated on the analysis of agrochemicals; synthetic and natural fertilizers and pesticides which continuously affect the human health. Samples of synthetic fertilizer, organic fertilizer and pesticides (insecticides, weedicides and fungicides) collected from selected CKDa prevalence areas were analyzed using atomic absorption spectrometer using hydride generator and graphite furnace. The highest amount of arsenic contamination was reported from triple super phosphate (TSP) used in cultivation of rice and it was in the range from 25 mg/kg to 37 mg/kg. Since the consumption of TSP for cultivation in Sri Lanka in 2012 was approximately 108,000 MT, the amount of arsenic introduced to Sri Lankan agricultural soils through imported TSP was calculated to be about 2100 kg. On contrary, organic fertilizer prepared with plant organic matter contained very low amounts of arsenic. Investigations carried out to detect presence of arsenic in pesticides showed 0.18 ppm to 2.53 ppm concentration of As. Arsenic has already been identified as one of the major etiological factors for the rapidly spreading CKDa among paddy farmers in the dry zone of Sri Lanka. Since analysis of soil profiles in the endemic areas had previously confirmed that source of arsenic is not from the bed rock, findings of the present study suggest that agrochemicals are the major source of arsenic in CKDa endemic areas.