Browsing by Author "Fonseka, S."

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Arsenic and hardness in ground water from Chronic Kidney Disease of Unknown Etiology (CKDU) prevalent areas and non-CKDU prevalent areas in Sri Lanka
(Postgraduate Institute of Science, University of Peradeniya, 2012) Fonseka, S.; Jayasumana, C.; Jayalath, K.; Amarasinghe, M.; Senanayake, K.; Wijewardhane, C.; Samarasinghe, D.; Dahanayake, K.; Mahamithawa, P.; Paranagama, P.A.
Increasing hardness and deteriorating quality of groundwater, the primary source of potable water, has been the general observation of inhabitants of areas where chronic kidney disease of unknown etiology (CKDu) is prevalent. Present study was conducted during 2011, to determine the groundwater hardness and presence of arsenic in Padavi- Sripura, Polpithigama, Moneragala, Thanamalwila in the dry climatic zone and in Pasagoda in the wet zone. Total hardness of the water samples collected from dug wells and tube wells was measured using EDTA titration (EPA 130.2) and arsenic content was measured using GF-AAS after filtration and acid digestion (EPA 7060A). Highest average groundwater hardness (466+34 mg l-1) was observed at Padavi-Sripura (n= 28) and the values ranged from 270+54 – 820+62 mg l-1). Arsenic content in water ranged from 21.07+3.54 to more than 100.91+12.31 !" #-1. The second most hardwater was found from Polpithigama area (n= 16) which ranged 90+8 – 615+47 mg l-1. Arsenic content in water ranged 2.49+0.61 – 60.55+7.21 !" #-1. The lowest hardness in groundwater among the test sites was observed at Moneragala (n=38), where the hardness ranged 10+2 – 340+31. The arsenic content ranged 2.14+0.84 – 52.47+6.71 !"#-1. Groundwater at Thanamalwila (n=19) recorded hardness value, i.e. 279+26 mg l- 1-with a range 170+8 - 500+24 mg l-1 and the arsenic content in water ranged 39.37+5.21- >100.42+9.45 !" #-1. Groundwater at Pasgoda, the control site of this study, was not hard (60+5 mg l-1) and arsenic was not detected. Statistical analyses reveal that a positive correlation exists between total hardness of groundwater and the arsenic content in it.
Determination of Arsenic Content in Synthetic and Organic Manure Based Fertilizers Available in Sri Lanka
(International Conference on Chemical Sciences, 2012) Fernando, A.; Paranagama, P.A.; Jayalath, K.; Fonseka, S.; Amarasinghe, M.D.; Senanayake, K.; Jayasumana, C.; Mahamithawa, P.; Wijewardhane, C.; Samarasinghe, D.; Dahanayake, K.S.
Phosphate fertilizer is a main source of arsenic in areas affected with chronic kidney disease of unknown etiology in Sri Lanka
(SpringerPlus, 2015) Jayasumana, C.; Fonseka, S.; Fernando, A.; Jayalath, K.; Amarasinghe, M.; Gunatilake, S.; Siribaddana, S.; Paranagama, P.A.
Chronic Kidney Disease of unknown etiology (CKDu) has escalated into an epidemic in North Central Province (NCP) and adjacent farming areas in the dry zone of Sri Lanka. Studies have shown that this special type of CKD is a toxic nephropathy and arsenic may play a causative role along with a number of other heavy metals. We investigated the hypothesis that chemical fertilizers and pesticide could be a source of arsenic. 226 samples of Fertilizers and 273 samples of pesticides were collected and analyzed using atomic absorption spectrometry and inductively coupled plasma mass spectrometry for arsenic and other heavy metals in two university laboratories. Almost all the agrochemicals available to the farmers in the study area are contaminated with arsenic. The highest amount was in triple super phosphate (TSP) with a mean value of 31 mg/kg. Also TSP is a rich source of other nephrotoxic metals including Cr, Co, Ni, Pb and V. Annually more than 0.1 million tons of TSP is imported to Sri Lanka containing approximately 2100 kg of arsenic. The next highest concentration was seen in the rock phosphate obtained from an open pit mine in NCP (8.56 mg/kg). Organic fertilizer contained very low amounts of arsenic. Arsenic contamination in pesticides varied from 0.18 mg/kg to 2.53 mg/kg although arsenic containing pesticides are banned in Sri Lanka. Glyphosate the most widely used pesticide in Sri Lanka contains average of 1.9 mg/kg arsenic. Findings suggest that agrochemicals especially phosphate fertilizers are a major source of inorganic arsenic in CKDu endemic areas. Organic fertilizer available in Sri Lanka is comparatively very low in arsenic and hence the farmers in CKDu endemic areas in Sri Lanka should be encouraged to minimize the use of imported chemical fertilizer and use organic fertilizers instead.
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.
Presence of arsenic in Sri Lankan rice
(Springer, 2015) Jayasumana, C.; Paranagama, P.A.; Fonseka, S.; Amarasinghe, M.; Gunatilake, S.; Siribaddana, S.
Background: Arsenic and heavy metals are implicated in causation of CKDu among farmers in dry zone of Sri Lanka. Rice has been identified as a major source of arsenic in research carried out in other countries. We analyzed 120 samples of new improved varieties (NIVs) and 50 samples of traditional varieties (TV) of rice for total arsenic content. Findings: Rice cultivated in Sri Lanka is contaminated with arsenic. Agrochemical dependent NIVs contain considerable amount (20.6 -540.4 μg/Kg) of arsenic. There is no difference between the arsenic content in NIV rice samples from areas where there is high or low prevalence of CKDu. TVs that are cultivated without using agrochemicals contain significantly less arsenic (11.6 - 64.2 μg/Kg). However, it is evident that the TVs also contain toxic metals if they are grown with fertilizers and pesticides. Conclusion: A high proportion of arsenic in rice exists in the inorganic form. Sri Lanka is a nation with high per capita consumption of rice. Codex Alimentarius recommends the maximum allowable limit for inorganic arsenic in rice as 200 μg/kg. Assuming that 70% of the total arsenic content exists in the inorganic form, this corresponds to a level of about 286 μg/kg of total arsenic. As such, 11.6% of the samples of NIVs exceeded this maximum recommended level in polished rice. Inorganic arsenic is a non-threshold carcinogen. Research should be focused on developing rice varieties that do not retain arsenic within the rice grain.