Browsing by Author "Edirisinghe, E.M.R.K.B."

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Determination of Heavy Metal Contamination of Some Aquatic Plants and Assessment of Health Risk
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Senarathne, E.M.N.S.; Edirisinghe, E.M.R.K.B.
Heavy metal contamination has become a crucial health matter to public health as they cannot be destroyed or degraded and persist in the environment for long time. People who live in North Central Province of Sri Lanka are victims of many health issues related to heavy metal consumption with their food and water. During last few decades, the soil and water in Sri Lanka are contaminated by heavy metals such as Arsenic, Cadmium, Mercury and Lead. Aquatic plants which grow in these contaminated water sources can absorb heavy metals through their roots, stems, leaves and store in plant body. This study was carried out to assess the toxicity levels of some aquatic food plants due to Cadmium and Arsenic. In this study, heavy metal contamination of some aquatic plant parts was assessed by Atomic Absorption Spectrometry (AAS). Forty two samples of three different aquatic food plants, leaves of Joyweed (Mugunuwenna, Alternantherasessilis, n = 15), seeds of Water lily (Olu, Nymphaeapubescens, n = 12) and tubes of Lotus (Nelum, Nelumbonucifera, n=15) were obtained from Madawachchiya area of Anuradhapura district of North Central province of Sri Lanka. The samples were digested by microwave accelerated digestion system and analyzed for Cadmium (Cd) and Arsenic (As) by AAS. The highest and the lowest Cd levels, 51.17 and 19.55 μg/kg, were reported in Lotus roots and joyweed respectively, while the highest and lowest levels of As, 420.57 and 121.54 μg/kg, were reported in joyweed and Lotus roots respectively. The Provisional Tolerable Weekly Intake (PTWI) of Cd, calculated based on standard value of 7 μg/Kg body weight, for extreme exposure of these plants were recorded as 8.21 Kg (lotus tubes), 17.60 Kg (water lily seeds) and 21.48 Kg (joyweed) per week of 60 Kg for body weight. However, the average vegetable consumption of a Sri Lankan is nearly 2.5 Kg/ week, thus not posing any health risk due to Cd. The PTWI values calculated for As, based on standard value of 15 μg/Kg body weight, were recorded as 2.14 Kg (joyweed), 3.36 Kg (water lily seeds) and 7.41 Kg (lotus tubes), thus contamination levels of As may cause health risk over long term consumption of joyweed and water lily seeds.
Habitat related variations and comparison of fatty acid composition of muscle and stomach contents of secondarily colonized Malabar Sprat (Ehirava fluviatilis) in Sri Lanka
(NeBIO, An International Journal of Environment and Biodiversity, Vol.10(3), pp.152-163, 2019) de Zoysa, H.K.S.; Amarasinghe, U.S.; Edirisinghe, E.M.R.K.B.; Sundarabarathy, T.V.
Ehirava fluviatilis is a marine origin clupeid found in Southern India and Sri Lanka, also found in two freshwater lakes, namely Parakarama Samudraya and Rajanaganaya reservoir, and that places are identified as secondarily colonizedhabitats. The objectives of this study were carried toinvestigate the fatty acid (FA) profile in the flesh of E.fluviatilis, to investigate the FA profile in the food of E. fluviatilis, and identify the impactof the FA profiles for colonisation. The Bligh and Dyer extracting method was used to lipids extraction of flesh and stomach contents of E. fluviatilis and Gas Chromatography (GC) was used to identify the different types of FAs. Data were statistically analyzed to examine the differences in the quantities of different FAs using ANOVA and principal component analysis (PCA). The predominant FAs were recorded in two different habitats ofE. fluviatilis in both flesh) and stomach contents. The only recorded difference between FAs profile was the presence of C 18:2 (n-4) in the Rajanganaya reservoir. The difference in the FA profile may lead to colonization of marine origin E. fluviatilis in Rajanganaya reservoir as a freshwater lacustrine habitat due to the ability of modification of FAs. Further, this study also indicates that the presence of specific FAs could be used as biomarkers to identify species.