Browsing by Author "Fonseka, S.I."

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Characterization of groundwater hardness with special reference to Polpithigama divisional area in Kurunegala district and potential use of plants to reduce water hardness
(2016) Fonseka, S.I.
Chronic arsenic toxicity among patients of Chronic Kidney Disease of unknown etiology (CKDu) in North Central Province, Sri Lanka
(University of Kelaniya, 2011) Jayasumana, M.A.C.S.; Paranagama, P.A.; Fonseka, S.I.; Amarasinghe, M.D.; Rajakaruna, L.; Wijewardena, C.
In recent years, a significant increase in patients of Chronic Kidney Disease of unknown etiology (CKDu) has been observed in some parts of Sri Lanka, especially in North Central Province. Uniqueness of this disease is that its victims do not share the same history as other kidney patients who have had it either due to diabetes, high blood pressure or glomerulonephritis. A reconnaissance survey was conducted in the 12 CKDu endemic villages, followed by a door-to-door visit for clinical assessment and biological sample collection of CKDu patients among the villagers (n=125). Control group (n=180) were selected from those individuals from the study area who had not been diagnosed to have CKDu and some of them were selected randomly from family members of CKDu patients. Hair and urine samples were collected from both CKDu patients and controls. The clinical assessment of patients and some individuals from control group had shown dermal manifestations of chronic arsenic (As) poisoning (CAP). 44.8% and 39.2%of the CKDu patients and 18.8% and 14.4% of the control group had hyper pigmentation of palms and soles respectively. 23.2% of the CKDu patients and 10.5% of the controls have shown keratosis of palms. In soles it was 17.6% and 8.3% respectively. Hair and urine samples from CKDu patients have shown presence of high amounts of As which exceed the toxic level. Generalized body weakness, headache, burning of eyes, nausea, mild to moderate hepatomegaly, epigastric pain and parasthesia, the other clinical symptoms of CAP were also observed among a significant proportion of CKDu patients in the sample but to a lesser extent among the individuals of the control group. Findings of the present study reveal that 52% of the CKDu patients and 14.4% of the subjects in the control group have shown symptoms required to be diagnosed CAP. Percentage CKDu patients who fulfill the requirements for CAP were greater than that among the control group. Observable CAP symptoms among individuals of the control group indicate that being inhabitants of the same area, consuming the same As-contaminated water, majority of the population has already bio-accumulated arsenic, nevertheless to a lesser extent than those who have been diagnosed as CKDu patients. This also implies that these individuals are of high risk in acquiring CKDu in the near future.
Nitrate, phosphate and sulfate concentrations of well water in CKDu endemic areas and non-endemic areas and their relation to water hardness
(Sri Lanka Association for the Advancement of Science, 2013) Fonseka, S.I.; Amarasinghe, M.D.; Paranagama, P.A.
Possible link of Chronic arsenic toxicity with Chronic Kidney Disease of unknown etiology in Sri Lanka
(Journal of Natural Sciences Research, 2013) Jayasumana, M.A.C.S.; Paranagama, P.A.; Amarasinghe, M.D.; Wijewardane, K.M.R.C.; Dahanayake, K.S.; Fonseka, S.I.; Rajakaruna, K.D.L.M.P.; Mahamithawa, A.M.P.; Samarasinghe, U.D.; Senanayake, V.K.
Preliminary Investigation of Water Hardness in Polpithigama Divisional Secretariat in Kurunegala District
(University of Kelaniya, 2012) Fonseka, S.I.; Jayasiri, U.D.S.C.; Amarasinghe, M.D.; Paranagama, P.A.
A frequent complaint of the inhabitants (primarily, farmers) of Polpithigama Divisional Secretariat in Kurunegala District, is the increasing hardness in dug wells and tube wells and as a result new wells are dug in search of water without hardness. Besides, a chronic kidney disease has been rapidly spreading among people within the last decade. A preliminary study was carried out to determine the ground water quality of the study area using dug-wells located in Mahawa, Siyambalangamuwa area. Sampling wells were chosen across an elevation gradient that extends from hills towards the paddy fields. Samples were taken from the surface of water and from the bottom of the well. Samples of groundwater in triplicate were collected into polypropylene bottles (rinsed with 10% nitric acid, followed by de-ionized water) from dug wells used by the villagers for drinking and domestic use. Immediately after measuring the pH of the water samples, 1 ml of concentrated HNO3 (0.1% v/v) was added to the sample bottle for preservation and they were brought to the laboratory. Calcium hardness, total hardness (Ca2+ and Mg2+) and other ions (PO4 3-,SO4 2-,NO3 -,CO3 2-) in water samples were measured. Ca2+ and total hardness were measured using EDTA titration. PO4 3-,SO4 2-,NO3 - contents were measured colorimetrically using spectrophotometer. An acid titration was used to determine the CO3 2-. Total hardness (as CaCO3) of water (n=20) ranged 150-420 ppm and Ca2+ hardness ranged 110–390 ppm. PO4 3- and SO4 2- contents of the samples ranged between 1 - 22.4 ppm and 12.5–605 ppm respectively. CO3 2- was ranged 24-492 ppm and NO3 - was ranged 1 – 6 ppm. Hardness of bottom layer of water in the wells was significantly higher than that of the surface water samples. These levels exceed WHO prescribed values for drinking water. Results substantiate the general complaint by the villagers in the study area that the quality of water is unacceptable for drinking. A potential cause of increasing groundwater hardness may be due to accumulating ions in the water from increasing amounts of inorganic ions leached into groundwater from agrochemicals used abundantly in this area.
Preliminary investigations on presence of arsenic in Sri Lankan soils & plants
(University of Kelaniya, 2011) Fonseka, S.I.; Amarasinghe, M.D.; Paranagama, P.A.
Arsenic is well recognized as an element of public concern due to its high toxicity and carcinogenic properties. Occurrence of chronic arsenic poisoning symptoms in patients of chronic kidney disease of unknown etiology (CKDu) from Padaviya area led to the hypothesis that chronic accumulation of arsenic may be the potential cause of CKDu. The most likely means of ingestion of arsenic may be groundwater as all CKDu patients have been consuming groundwater, and not surface water for the last few decades. Presence of inorganic and organic arsenic is evidently the result of presence of it in groundwater and interstitial (soil) water from which it can enter plants. The present study therefore, was carried out with the objective of determining arsenic content in soil profiles as well as selected aquatic and terrestrial plants in Padaviya area with a view to understanding the vertical and horizontal (spatial) distribution of arsenic in the environment. Soil samples were taken at 1 foot depths down to 12 feet from paddy fields, homesteads and areas of Padaviya reservoir using a spiral auger. Soil was also collected from Deniyaya (Pasgama), a non-CKDu endemic area, as control samples. Three samples were taken from every one-foot depth in the soil profile and collected into polythene bags. The auger was cleaned thoroughly to remove all soil and washed with de-ionized water prior to taking samples. Samples of roots, leaves, flowers and bark of common trees, shrubs and herbaceous plants in the study area were collected in plastic bags and brought to the laboratory to test for the presence of arsenic. Control plant samples were collected from non-CKDu areas. Soil particle sizes and cation exchange capacity were determined using standard methods; organic matter was measured using weight loss on ignition. Soil and plant samples were acid digested using nitric (4): suphuric (1): perchloric acid (1) mixture until a clear solution was obtained and the digested samples were used to detect arsenic in them using the hydride generator and atomic absorption spectrometer. Distribution of Fe and Al in soil that affects bioavailability of arsenic in soil and groundwater was determined using oxalate-extraction method. All surface soil samples contained total arsenic contents greater than those in the bottom horizons of the soil profiles. Surface layers of soil in paddy fields of Padaviya area were detected to have relatively high levels when compared to that of the deep layers. On the contrary the As level in the deep layers of soil in the control area in the wet zone recorded higher values than that of the surface which could be attributed to the greater incidence of leaching that is possible in wet zone soils. No As arsenic was detected below 7 feet depth in Padaviya reservoir. Relationship between distribution of oxalate-extractable Fe with presence of As in soil will be discussed. Bark of Azadirachta indica (Kohomba) was found to accumulate the greatest amount of total As while it was observed that roots and leaves of Terminalia arjuna too accumulate As more than the other tree species. Eichhornia crassipes, the aquatic floating plant and flowers of Nelumbo sp. (rooted aquatic plant) were found to contain excessive amounts of As, indicating their capacity to hyper-accumulate As and thus their potential to be used as candidate species in arsenic phytoremediation.
Presence of Arsenic in Pesticides used in Sri Lanka : A Preliminary Analysis
(Water Resources Research in Sri Lanka, 2011) Jayasumana, M.A.C.S.; Paranagama, P.A.; Amarasinghe, M.D.; Fonseka, S.I.; Wijekoon, D.V.K.