Environmental Management
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Item Diversity and Species Composition of Midgut Symbiotic Bacteria in Culex quinquefasciatus Mosquitoes in Gampaha District, Sri Lanka(Wiley, 2024) Ranasinghe, Koshila; Hathnagoda, Randi; Gunathilake, Pinidi; Buddhinee, Thilini; Welgama, Pabasara; Gunarathna, Hasini; Perera, HarshaniMosquitoes, notorious for their deadly impact as disease vectors, also hold economic value due to their role in disease transmission. This study focuses on understanding mosquito gut microbiota as a foundation for innovative vector control strategies aimed at reducing disease spread. Conducted in the Gampaha Medical Officer of Health (MOH) area in Sri Lanka, the research aimed to explore microbial diversity within the midgut of Culex quinquefasciatus, an essential step to support ongoing paratransgenesis efforts. Sampling was conducted using standard mosquito collection techniques, and bacterial isolates from midgut homogenates were cultured on Plate Count Agar and identified through biochemical testing. The most abundant bacterial families were further analyzed using DNA extraction, PCR amplification, and gene sequencing for species-level identification. The study identified four bacterial families (Staphylococcaceae, Streptococcaceae, Neisseriaceae, and Moraxellaceae) in adult mosquitoes, with an additional family, Micrococcaceae, found in larvae. Notably, the relative distribution of midgut bacteria varied significantly among field-caught larval and adult strains from different study areas (chi-square = 1.673; P < 0.05), suggesting a consistent bacterial flora across mosquito life stages and geographic locations. A key finding was the detection of Lysinibacillus sphaericus, a bacterium with strong potential for use in paratransgenesis. Given the high mosquito density in the region, implementing paratransgenesis for Cx. quinquefasciatus control is recommended. Additionally, understanding gut microbial composition may enhance integration of modified microbiota into existing Sterile Insect Technique (SIT) and Incompatible Insect Technique (IIT) strategies in Sri Lanka.Item Toxicity assessment of powdered laundry detergents: an in vivo approach with a plantbased bioassay(Springer Nature, 2024) Jayalal, Nimmi, Apsara; Yatawara, MangalaPowdered laundry detergents, encompassing a diverse blend of organic and inorganic compounds, are crucial in efficiently removing dirt in household cleaning. This study investigated the cytotoxic and genotoxic potential of commonly used powdered laundry detergents in Sri Lanka using the Allium cepa bioassay. Five detergents (four branded A, B, C, and D, and one non-branded E) were selected for assessment. Toxicity evaluations were conducted across a range of predetermined aqueous detergent concentrations (0–2500 mg/L) using the A. cepa bioassay, with all experiments being triplicated and following standard protocols. Exposure to detergent concentrations up to 500 mg/L resulted in mitosis suppression, nuclear aberrations, and chromosomal abnormalities in A. cepa, indicating concentration-dependent cytotoxicity and genotoxicity. Condensed nuclei were notably prevalent among nuclear abnormalities, while vagrant chromosomes and chromosomal adherence were the most frequent chromosomal aberrations observed. At higher concentrations (> 500 mg/L), the selected detergents induced necrotic cell death in A. cepa root meristematic cells. This study warns to avoid the unnecessary use of detergents as they cause significant ecological risks and advocates for further research to comprehensively assess detergent toxicity across diverse organisms within ecosystems to safeguard ecosystem health effectively.Item A Systematic Review and Global Trends on Blue Carbon and Sustainable Development: A Bibliometric Study from 2012 to 2023(2024) Pang, Shufen; Majid, Mazlinawati Abdul; Perera, Hadinnapola Appuhamilage Chintha Crishanthi; Sarkar, Mohammad Saydul Islam; Ning, Jia; Zhai, Weikang; Guo, Ran; Deng, Yuncheng; Zhang, HaiwenHalfway through Transforming Our World: The 2030 Agenda for Sustainable Development, only 15 percent of the goals have been reached. As a carbon storage and climate change mitigation mechanism, blue carbon is closely related to sustainable development goals and plays an important role in the global carbon cycle. In spite of its great potential, blue carbon still faces several challenges in terms of achieving the Sustainable Development Goals. Herein, this review aims to retrieve all known impacts of blue carbon on sustainable development through research published on the Web of Science from 2012 to 2023 using a sequence of bibliometric analyses. Keywords such as “blue carbon” and “sustain*” (including “sustainability”, “sustainable”, etc.) were used for article extraction. CiteSpace, a science mapping tool, was used to capture and visually present the bibliometric information in the research about blue carbon and sustainable development. Upon reviewing the existing literature, no study has concentrated on bibliometrically analyzing and visualizing studies about blue carbon and sustainable development. This study sets out to fill this gap by examining the key areas of concentration in published works on blue carbon and sustainable development from 2012 to date. Moreover, the integration of blue carbon and sustainable development may help to develop supportive policies for marine carbon sinks. Despite the valuable contribution of this study to the blue carbon and sustainable development body of knowledge, generalizations of the results must be made cautiously due to the use of a single database, which in this case is the Web of Science.Item Exploring the Relationships between Tradeoffs and Synergies among Island Ecosystem Service Bundles: A Study on Zhoushan Archipelago Located on the Southeast Coast of China(2024) Xiao, Yang; Zhang, Huan; Ma, Ke; Perera, Hadinnapola Appuhamilage Chintha CrishanthiDue to the rapid rise of China’s coastal economic zone, the urbanization of the surrounding islands has accelerated. Intensive disturbance caused by human activities and frequent changes in land types have resulted in the continuous erosion of ecological sources and the degradation of ecosystem services on the islands year by year. It is particularly important to explore sustainable development strategies for the islands to achieve a balance between conservation and development, which is particularly important for the islands in the process of urbanization. Taking Zhoushan Archipelago as an example, this paper uses multi-source spatial data and employs InVEST models and USLE to quantify island ecosystem services. Furthermore, using principal component analysis and cluster analysis, the study aims to identify clusters of island ecosystem services and investigate their tradeoffs, synergistic mechanisms, and regional heterogeneity using spatial analysis. In addition to providing island urban planners with effective zoning governance recommendations and assistance in spatial planning to promote coordinated and sustainable development, the findings of this study can assist in the development of appropriate management plans for each ecological functional service cluster on islands.Item Herpetofaunal diversity and endemism in a fragmented forest patch: a study in Dombagaskanda forest reserve(2023) Sandeepa, S. P. M.; Chandrasekara, W. U.Fragmented forest patches provide refuge for distressed animal forms including amphibians and reptiles (herpetofauna) but an array of adverse anthropogenic impacts often threatens them. Surrounded by human settlements, the Domabagaskanda Forest Reserve (DFR) is one such small, threatened, fragmented forest patch (area 192 ha) in the wet zone of the country. In this research, we studied the variation of the herpetofaunal diversity along a seasonal and spatial scale in the DFR and evaluated their endemism and conservation status against the National Red List 2012 of Sri Lanka. The research design included surveying herpetofauna within (viz. forest zone and monastery zone) and around the DFR (viz. outer buffer zone) during the wet season (November to December 2022) and dry season (January to March 2023) using a quadrat sampling strategy. The herpetofauna diversity in these three zones was calculated using the species richness (SR), Shannon-Weiver index (H’), and Pielou’s evenness index (J’). The canopy cover, air and soil temperature, humidity, and tree diameter in the quadrat sampling areas were also measured. A total of 125 individuals belonging to 14 reptilian and 11 amphibian species were identified. They showed a distinct spatial variation where their total abundance and diversity within the monastery zone were greater (N=40, SR=14, H’=2.507, J’=0.9501) than in the forest zone (N=26, SR=13, H’=2.418, J’=0.9427) and the peripheral buffer zone (N=21, SR=9, H’=1.934, J’=0.8801). They also showed a seasonal variation where their total abundance and diversity were higher during the dry season than in the wet season. Five (05) reptile and 08 amphibian species were endemic to Sri Lanka, representing 42% reptilian and 73% amphibian endemism. The endemism percentage (%) of herpetofauna within the DFR is 56.5%, which is 13 times higher than that in the outer buffer zone (4.6%). Of the 05 endemic reptile species, 02 are endangered, whereas of the 08 endemic amphibian species, 04 are endangered. Despite its small size, results suggest that the DFR is a rich biodiversity repository with a high herpetofaunal endemism, of which most are endangered. Results also insist on the grave need to protect and conserve small, fragmented forest patches, similar to DFR, from further human threats.Item Variation of water quality parameters and brush park fish diversity: a study in Negombo estuary(2023) Ratnayake, R. P. P.; Chandrasekara, W. U.In the Negombo estuary, the brush park fishery is confined to two small zones along its Eastern Katunayake side and the Western Dungalpitiya side, with approximately 50 brush parks each. In this research, we investigated what factors, whether seasonal or water-quality related, contributed to the brush park fishery being confined into these two zones. Three (03) randomly selected brush parks were sampled from each zone during the rainy season (November to December 2022), and the fishes in each brush park were identified to the maximum possible taxonomic category and enumerated separately. Further, the water quality parameters within those selected brush parks were measured using standard field and laboratory procedures. This procedure was repeated for another set of 03 brush parks in each zone during the dry season (February to April 2023). The fish diversity in each brush park was calculated using the Shannon-Weiver (H’) and Pielou’s evenness (J’) indices. Fish abundance data and water quality data between the two zones and between the two seasons were analysed parametrically and nonparametrically as appropriate. Altogether, 18 taxa belonging to 16 finfish and shellfish families were recorded. Of the water quality parameters measured, the salinity, electrical conductivity, dissolved phosphates, and Ch-a increased significantly at both zones during the dry season. These water quality changes induced many marine species, including Siganus sp. and Acanthophagous berda to migrate into the two zones, resulting in Siganus sp. contributing about 42% and Acanthophagous berda contributing about 33% of the fish catch at Dungalpitiya and Katunayake, respectively. When the salinity, in particular, dropped near zero in both zones during the rainy season, these marine species migrated back. The same salinity drop induced the freshwater Macrobrachium rosenbergii to migrate into the two zones in large numbers during the rainy season, contributing about 61% and 30% of the fish catch at Katunayake and Dungalpitiya, respectively. It was apparent that M. rosenbergii dominates the brush park fish catch during the rainy season, while the marine Siganus sp. and A. berda dominate it during the dry season. The brush park fish diversity was higher in both zones during the dry season than in the wet season. For example, the SR, N, H’, and J’ at Katunayake during the dry season were 15, 425, 1.651, and 0.6098, while 7, 87, 0.5189, and 1.01 during the wet season. Results also suggest that the seasonal and zonal changes of salinity, dissolved phosphates, and Ch-a govern the brush park fish diversity in the Negombo estuary.Item Knowledge, perceptions and practices on healthcare waste management and associated occupational health hazards among healthcare professionals in the Colombo District, Sri Lanka: a cross-sectional study(2023) Udayanga, Lahiru; Sahana, Loganatahan; Perera, Ayesha; Ranasinghe, Koshila; Ranathunge, TharakaBackground: Proper Healthcare Waste (HW) management is directly influenced by the knowledge and attitudes of Healthcare Professionals (HCP). However, studies that characterize the knowledge and practices of HCP on HW management are limited in Sri Lanka. This study was conducted to characterize the knowledge, perceptions and practices of HCP on the management of HW and to determine the risk factors influencing HW related occupational health hazards in the Colombo District of Sri Lanka. Methods: A total of 407 HCP were recruited as the study population from selected hospitals in the Colombo District. Information on sociodemographic factors, knowledge, attitudes and practices on HW management were gathered using an interviewer-administrated questionnaire. The Binary Logistic Regression (BLR) was used to determine the socio-economic risk factors associated with the occurrence of HW related health issues among the respondents. Results: The majority of respondents were characterized with a high knowledge level (76.9%) and positive attitudes (53.8%) on HW management. Incineration (82.6%) was recognized as the most widely used HW treatment method. Personal Protective Equipment (PPE) was used at a satisfactory level (85.5%), while liquid waste treatment was limited (57.5%). The occupational designation, level of training received in HW management, professional experience, vaccination status for tetanus, degree of knowledge and attitudes on HW management were recognized as significant risk factors (p < 0.05) associated with the occurrence of HW related occupational hazards. Conclusion: Even though, the treatment of HW was satisfactory, strengthening the existing mechanisms for monitoring of HW management, provisioning more resources and organizing training and awareness programmes on HW management for HCP are recommended.Item Choice Experiment Analysis of Non-market Values of Ecosystem Services(springer, 2022) Dissanayake, Sahan T. M.; Vidanage, Shamen P.Small tank cascade systems (STCS) are clusters of hydrologically interconnected irrigation reservoirs with a 2500-year history located in the dryzones of Sri Lanka. They provide irrigation to 40 per cent of the irrigable land and a host of other benefits. The maintenance of STCS was neglected historically partly due to the low recognition of their true value. We highlight how choice experiment surveys and extended benefit-cost analysis can be used to elicit the full value of conducting environmental restoration projects with application to STCS. Respondents have a positive willingness to pay for the restoration (over LKR 78 million for the onsite sample). The cost-benefit analysis proves that cascade restoration is justified.Item Heavy metal concentrations in the edible portions of Centella asiatica: Health risk toward chronic kidney disease of uncertain etiology(Department of Zoology and Environmental Management, Faculty of Science, University of Kelaniya, Kelaniya, Sri Lanka., 2021) Wijeyaratne, W. M. Dimuthu Nilmini; Kumari, Ellewaththe Arachchilage Charuni SewwandiCentella asiatica is a commonly consumed green leafy vegetable in many developing countries due its high nutritious value and availability at low cost. The present study was conducted to assess the Cd, Cr and Pb uptake associated health risks of Centella asiatica harvested from organic and non-organic cultivations in a chronic kidney disease of uncertain etiology (CKDue) prevalent area in Sri Lanka. The health risk assessment was conducted in terms of the bioconcentration factor (BCF), soil-to-root and root-to-leaf translocation factors ( TF (soil-root) and TF (root-leaf) ), Target hazard quotient for each heavy metal (THQ) and hazard index (HI). In addition, the spatial variation of physical and chemical parameters of the root zone soil were assessed using MINITAB 17 statistical software. Results indicated significant spatial variations in conductivity, organic matter content and Cr concentrations among organic and non-organic study sites. The Cr, Cd and Pb concentrations recorded from roots and leaves of Centella asiatica were higher than the safe limits for consumption established by the European Union. The health risk analysis indicated that there is a potential of hyper-accumulating Cd in the roots of Centella asiatica. Further, the THQ and HI of the heavy metals indicated possible adverse non-cancer health risks associated with long-term consumption of leaves of Centella asiatica. Therefore, necessary precautionary actions to prevent the excessive buildup of Cr, Cd and Pb in the edible portions of Centella asiatica are essential in order to ensure consumer safety.Item Macrophytes as indicators of the ecological status of a tropical rehabilitated wetland ecosystem: Application of multivariate statistics and Ecological State Macrophyte Index (ESMI)(Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka., 2021) Wijeyaratne, Dimuthu; Bellanthudawa, AravindaThe present study used the Ecological State Macrophyte Index (ESMI) and the multivariate statistical methods to assess the ecological status and the variation of macrophytes in a tropical wetland system. Six sites were selected from rehabilitated and non-rehabilitated areas of an urban tropical wetland and the water quality parameters (water pH, temperature, conductivity, total dissolved solids (TDS), dissolved oxygen (DO), visibility, biological oxygen demand 5 days after incubation (BOD5), chemical oxygen demand (COD), nitrate, chlorophyll-a and total phosphorus concentrations), sediment quality parameters (pH, organic matter content, percentage sand, silt and clay content) and abundance of aquatic macrophytes were measured. Shannons Weiner diversity index, percentage vegetation under anthropo-pressure, macrophyte settlement rate and ESMI were calculated. Significant variations in the water and sediment quality parameters were observed and ten species of aquatic macrophytes were recorded. Salvinia melosta and Cypreus iria were recorded only from the non-rehabilitated sites. Although there was no significant difference in the percentage anthropo-pressure among study sites, the rehabilitated sites were displayed low anthropo-pressure. The sites in the non-rehabilitated area showed a significantly lower macrophyte settlement rate