DSpace Collection:http://repository.kln.ac.lk/handle/123456789/37472024-03-28T10:08:11Z2024-03-28T10:08:11ZThe Groundwater Geochemistry and the Human Health Risk Assessment of Drinking Water in an Area with a High Prevalence of Chronic Kidney Disease of Unknown Etiology (CKDu), Sri LankaBotheju, W. S. M.Liyanage, J. A.Kannangara, S. D. P.Corchado, J.http://repository.kln.ac.lk/handle/123456789/238342021-11-04T06:47:52Z2021-01-01T00:00:00ZTitle: The Groundwater Geochemistry and the Human Health Risk Assessment of Drinking Water in an Area with a High Prevalence of Chronic Kidney Disease of Unknown Etiology (CKDu), Sri Lanka
Authors: Botheju, W. S. M.; Liyanage, J. A.; Kannangara, S. D. P.; Corchado, J.
Abstract: Chronic kidney disease of unknown etiology (CKDu) has become an alarming health issue in Sri Lanka. ,e disease is more
notable among farming communities and people who consume groundwater as their main source of drinking water. To assess the
possible links between drinking water chemistry and expansion of CKDu, the study was compared with hydrogeochemical data of
drinking water sources in a CKDu prevalent area (Girandurukotte GND, Badulla District) and a reference area (Dambethalawa
GND, Ampara District) in Sri Lanka. Based on the results, nephrotoxic heavy metal (Cd, Cr, Pb, and As) concentrations were
significantly higher in the CKDu prevalent site than the reference area, compromised the harmful consequences to the people in
the CKDu hotspot. Results of the inverse distance weighted (IDW) interpolation tool indicated the nephrotoxic heavy metals
contents including Cd, Pb, As, and Cr in CKDu hotspot were changed in the ranges of 9.78–187.25 μg/L, 0.08–0.66 μg/L,
20.76–103.30 μg/L, and 0.03–0.34 μg/L. ,e random distribution patterns were shown by the result in Moran’s index values.
Noteworthy, the results have emphasized a strong association between fluoride and water hardness. ,e frequency of occurrence
above the threshold limit of fluoride was 28% in non-CKDu water samples, while 81% in CKDu prevalent sites. ,e hardness
values in the CKDu prevalent site indicated “moderately hard water,” while the non-CKDu area indicated the “soft water.”
Furthermore, this paper quantified overall water quality and heavy metal contamination and assessed the human health risks
associated with drinking water. According to the results of the water quality index, 90% of the samples in the CKDu prevalent area
were classified as “poor water” and “very poor water” for drinking purposes, while 73.33% of the samples in the non-CKDu area
were “good” and “excellent” for drinking usage. Calculated chronic daily intake (CDIoral) and hazard quotient (HQoral) of
nephrotoxicants were higher in CKDu hotspot than the non-CKDu site. Besides, the hazard index (HI) values obtained for the
CKDu prevalent area exceeding the acceptable limit (HI � 1) indicated potential health risks to the people in those areas. ,is
study suggests that long-term exposure to nephrotoxic heavy metals, water hardness, and fluoride present in drinking water may
threaten human health and affect kidney functions. ,erefore, regular monitoring and better management of water supplies in
CKDu prevalent areas are essential to determine the contamination load and reduce the health impacts due to excessive and longterm
exposure to the nephrotoxicants.2021-01-01T00:00:00ZSpatial Variation in Trophic Structure of Dominant Fish Species in Lake Dongting, China during Dry SeasonYu, J.Guo, L.Zhang, H.Xu, J.Hu, H.Xue, TLuo, C.Yi, C.Hu, Y.De Silva, K.Xie, P.http://repository.kln.ac.lk/handle/123456789/238152021-11-01T20:52:34Z2018-01-01T00:00:00ZTitle: Spatial Variation in Trophic Structure of Dominant Fish Species in Lake Dongting, China during Dry Season
Authors: Yu, J.; Guo, L.; Zhang, H.; Xu, J.; Hu, H.; Xue, T; Luo, C.; Yi, C.; Hu, Y.; De Silva, K.; Xie, P.
Abstract: Understanding trophic interactions in food webs is crucial to revealing the transfer
of substances and energy from primary food sources to consumers in aquatic ecosystems.
We hypothesize that the trophic structure of consumers can be significantly affected by primary food
sources (pelagic, benthic, and littoral sources) through complex trophic interactions. This study used
stable isotope analysis and Bayesian mixing models to estimate the trophic levels of fish consumers
and the contributions of primary food sources in the three sub-lakes (Eastern, Southern, and Western
Dongting) of Lake Dongting, which have different physical and chemical parameters of water, fish
species diversity, and plankton (phytoplankton and zooplankton) density. Results showed the
differences in community structures of fish among sub-lakes. Fish trophic levels were significantly
higher in Eastern Dongting than those in the two other areas. The contributions of primary food
sources to fishes were as follows: the pelagic source was the main basal food source in Eastern
Dongting, and littoral and pelagic sources played equally essential roles in Southern Dongting;
fishes in Western Dongting relied on more benthic source to growth than those in the two other
regions. This study can fill gaps in our knowledge of the influence of the underlying food available
on trophic structure of consumers by exploring the role of primary food sources and making the
trophic structure of consumers in the aquatic food web highly complicated and diverse through
control of the distribution of primary food sources.2018-01-01T00:00:00ZSubstrate characteristics and species diversity of marine angiosperms in a micro-tidal basin estuary on the west coast of Sri LankaDe Silva, K.Amarasinghe, M.http://repository.kln.ac.lk/handle/123456789/238142021-11-01T20:44:20Z2010-01-01T00:00:00ZTitle: Substrate characteristics and species diversity of marine angiosperms in a micro-tidal basin estuary on the west coast of Sri Lanka
Authors: De Silva, K.; Amarasinghe, M.
Abstract: Diversity of marine angiosperm species (seagrasses) at Kadolkele in Meegamuwa (Negombo) estuary was studied with a view to understanding the effect of substrate characteristics on diversity. Seagrass samples were obtained along three line transects, laid perpendicular to the shoreline at 20 m intervals. Shannon-Wiener index was used to determine the species diversity of seagrasses in the study site at Kadolkele that was divided into three strata, demarcated by the distance, i.e. 0-10 m, 10-20 m and 20-30 m from the shoreline. Comparison of Shannon-Wiener index values indicated that the diversity of first stratum close to the shoreline was significantly different from that of the other two among which no significant difference was found to occur. Substrate pH, soil electrical conductivity, organic mater content and particle size distribution were measured from the substrate samples taken from each stratum. No statistically significant difference was observed with pH (3.92-6.82) and particle size distribution among the three strata. Soil electrical conductivity and organic matter content of stratum 3 however, was significantly different (p< 0.05) from the other two strata. Kadolkele seagrass bed consisted of two species and Halodule pinifolia (5822 shoots m-2) dominated over Halophila ovalis (1030 shoots m-2). The area adjacent (0-3 m) to the mangroves at the shoreline was devoid of seagrasses and H. ovalis was absent in stratum 1, indicating that substrate characteristics have a marginal effect on the species richness of the seagrasses. Although species richness was similar in the other two strata, higher (Shannon) evenness (0.231), despite the relatively low abundance in stratum 2, contributes to its higher species diversity. Present study therefore documents the subtle habitat partitioning of co-existing marine angiosperm species in a limited area in Meegamuwa estuary.2010-01-01T00:00:00ZTHE OTTER AS AN UMBRELLA SPECIES IN CHINADE SILVA, K.H.W.L.http://repository.kln.ac.lk/handle/123456789/238112021-11-01T20:21:20Z2021-01-01T00:00:00ZTitle: THE OTTER AS AN UMBRELLA SPECIES IN CHINA
Authors: DE SILVA, K.H.W.L.
Abstract: The aim of this survey was to assess the current presence of otter along the River Dee, in Aberdeenshire, Scotland, through a series of spot-checks for field signs indicating otter activity along the riverbanks carried out from its upper reaches at the White Bridge in the Forest of Mar down to the coast at Greg Ness (approximately 125km). Spraint sites were the most abundant field signs observed along the course of the River Dee, with a total of 208 spraint sites found, the majority of which consisted of fresh or recent spraints (n = 162; 77.9%). The fresh or recently deposited spraints were found throughout upper, mid and lower regions of the River Dee surveyed. Both in situ and laboratory-based spraint analysis was performed to give an index of the diet of otters utilising the River Dee. The Salmonids (Salmon and Trout species) were the dominant prey item observed in the spraints along the River Dee but mammal remains were the dominant prey item found in spraints on the tributaries of the River Dee. Eel (Anguilla anguilla) remains were more prevalent than salmonids from spraints on the tributaries. Mammal remains were the most frequent non-fish items found in all spraints observed in this survey. Other non-fish items included bird, amphibian and crab remains.2021-01-01T00:00:00Z