International Postgraduate Research Conference (IPRC)
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Item Assessment of the Heavy Metal Concentrations in Mangrove Leaves of Negombo Lagoon(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Handagiripathira, H.M.N.L.; Deeyamulla, M.P.; Koichiro, S.Mangrove ecosystems play an important role in the biogeochemistry of heavy metal contamination in tropical coastal areas. During the last decades, heavy metals are one of the most serious contaminants in those environments due to its toxicity, durability and bioaccumulation problems with the long residence time within the food chain. Mangrove leaves are the primary producer of the food chains or food webs in mangrove ecosystems where there is a direct effect on the human health. The bioaccumulation levels of heavy metals in mangroves can be estimated by assessing such levels in leaves, sediments and water in the study area. This study was a part of a M.Phil. research and the main objective of this study was to assess the concentrations of selected heavy metals to understand the levels of contamination in the mangrove leaves in a selected lagoon system. The 27 locations of Negombo lagoon which is situated in urbanized area in Gampaha District of Sri Lanka was selected for the study. Four mangrove species of Rhizophor amucronata, Rhizophora apiculata, Avicennia marina and Lumnitzera racemosa were chosen since these arethe most common species in the lagoon. Mangrove leave samples categorized as young, matured and old and were collected in the wet and dry seasons of 2015 and 2016. Leave samples were cleaned and oven dried prior to grinding for fine powder. The elemental concentrations of heavy metals, Mn, Fe, Cr, Co, Ni, Cu, Zn, As, Hg and Pb were analyzed in the dried powder of mangrove leaves (297 samples) using Particle-induced X-ray emission (PIXE) technique established in Medical University, Iwate, Japan. The results were evaluated to study the spatial and temporal variations of heavy metal concentrations in mangrove leaves of the Negombo lagoon. The distribution of metals in mangrove leaves were departed and depended on the mangrove species as well as climatic seasons in study period. The most prominent species of R. mucronata, R. apiculata were represented by 262 samples and both species were having same concentration levels except Mn and Zn, which act as essential plant nutrients, were greater in R. apiculatathan the other species. The ranges of metal concentrations (in ppm) of R. apiculata leaves in the studied area were observed in the order: Mn (15.2-453.0) > Zn (5.4-276.4)> Fe (28.6-224.9) > Cu (0.1-9.3)> Cr (0.2-7.3)> Hg (ND-5.9)> Pb (ND-4.0)> Ni (ND-2.3)> Co (ND-1.7)> As (ND-1.0). The heavy metal uptake by young, matured and old leaves were showed significant deviations for most of the studied metals. Cr content in all leaves was same and some metals (ie. Fe) were higher in old leaves and some metals (ie. Zn) were higher in young leaves. A comparative evaluation of studied metals was carried out with the similar studies conducted in the world. In general, heavy metal concentrations in mangrove leaves of Negombo lagoon were lower than the permissible limits as recommended by WHO (1996), except Cr, Zn and PbItem Background Levels of Heavy Metals in Moss Hyophila Involuta as A Bioindicator Using Four Strict Nature Reserves in Sri Lanka: Sinharaja Rainforest, Knuckles Mountain Range, Horton Plains National Park and Hakgala Mountain Forest(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Jayalath, J.I.K.G.; Deeyamulla, M.P.; de Silva, R.C.L.Atmospheric deposition of six heavy metals (Zn, Cu, Pb, Ni, Cr and Cd) using the moss Hyophila involuta as a bioindicator was investigated to establish the background levels of heavy metals for different geographical and climatic zones of Sri Lanka. Moss sampling was carried out in four strict nature reserves in different geographical and climatic zones of Sri Lanka, namely Sinharaja rainforest (6°24′–6°27′ N, 80°24′–80°26′ E, 450– 500 m) from wet zone, Knuckles mountain range (7°31′ N, 80°43′ E , 1,000–1,300 m) from intermediate zone, Horton Plains National Park (6°46′–6°48′ N, 80°47′–80°49′ E, 2,000–2,200 m) and Hakgala mountain forest (6°55′ N, 80°48′ E, 1,700–1,800 m) from wet zone and Central highlands using about 10 sampling sites from each location within a month from October to November 2015. Concentrations of heavy metals in moss were analysed by using atomic absorption spectrometer. The atmospheric deposition of heavy metal concentrations in all sampling stations is given for dry weight of moss and the ranges of six elements around four strict nature reserves were 9.58– 65.68, 1.87–9.97, 1.20–10.56, 1.12–7.81, 1.20–10.60 and 0.05–0.36 μg/g for Zn, Cu, Pb, Ni Cr and Cd separately. According to the statistical analysis (one-way ANOVA , p < 0.05), accumulation of Cu, Cr and Cd in moss was not significantly change among four strict nature reserves and accumulation of Ni and Pb in moss was significantly higher around Hakgala mountain forest. Atmospheric deposition of Zn in moss was significantly higher around Knuckles mountain range area than other sampling locations. Therefore background levels of heavy metals in moss can be expressed as as 5.53 (±1.75), 7.23 (±2.11), 4.03 (±1.41), 6.61 (±2.58) and 0.17 (±0.06) μg/g for Cu, Pb, Ni, Cr and Cd respectively for the most of the geographical and climatic zones of Sri Lanka and background levels of Zn can be established as 30.62 (±8.11) and 47.42 (±12.31) μg/g for wet zone including Central highlands and intermediate zone of Sri Lanka respectively.Item Stable isotopic characterization and baseline monitoring on mangrove ecosystem in Negombo lagoon using carbon and nitrogen stable isotopes(Faculty of Graduate Studies, University of Kelaniya, 2015) Handagiripathira, H.M.N.L.; Deeyamulla, M.P.; Rogers, K.; Waduge, V.A.The stable isotope ratios of 13C/12C and 15N/14N and the weight ratio of total carbon to total nitrogen (C:N) are important indicators in the field of environmental monitoring. As a part of the assessment of nutrient enrichment in Negombo lagoon ecosystem, stable isotope technique is used to study the stable isotope ratios of mangroves and adjacent water. Although this technique is an advanced tool to identify the fingerprints of environmental pollutant sources, totally newel to the research field in Sri Lanka. The fresh mangrove leaves (young, matured and old) of Rhizophora apiculata and Rhizophora mucronata spices, totally 35 samples and 10 surface water samples were collected from 12 sampling points randomly selected from the bank of Negombo lagoon. The leaves were rinsed with distilled water, oven dried at 40 0C for 48 hours and powdered. The water samples were filtered into glass fiber filters to collect suspended particulate materials in the water and filter papers were oven dried at 40 0C for 24 hours. Samples were analyzed by combustion on a Eurovector elemental analyzer coupled to an Isoprime mass spectrometer in GNS science, New Zealand. There were some effects of %Nitrogen (%N) on the old leaves where the %N is quite low (range 0.3% to 1.7% with a mean value of 0.6%), but generally young and matured leaves had similar trend in % N (range 1.1% to 2.9% with a mean value of 1.8% and range 0.7% to 2.9% with a mean value of 1.5% respectively). The behavior of isotopic Nitrogen-15 ratio (15N) in those three types of mangrove leaves was significantly divers compared with behavior of %N in leaves. The range of 15N in young and matured leaves was from 2.3‰ to 12.3‰ with a mean value of 5.4‰ and this ratio in old leaves had a range from 5.1‰ to 8.0‰ with higher average of 6.52‰. The average % Carbon values (%C) of all the three types of mangrove leaves were in the range of 42% to 43%. The isotopic Carbon-13 ratio (13C) of young, matured and old leaves was within the common range for C3 plants, with values ranging from -25.4 to -32.7‰ and average of -29.5‰. The total Carbon to total Nitrogen ration (C: N, atom) had increased in older leaves (range 36.2 to 163.3 with mean value of 120.8), and significantly decreased in matured and young leaves (average values of 41.9 and 34.5 respectively). The average 13C value of the lagoon water was -24.6‰ and average 15N value of the water was 6.7‰. The carbon and nitrogen isotopic compositions obtained in this study are comparable with previously published results in the other coastal regions of the world. As an initiative research study on the stable isotope analysis in Sri Lanka, the results and findings, generated in this study can be considered as the baseline data for future studies based on the lagoon ecosystem.Item Phytoremediation potential of Talinum triangulare (Ceylon spinach) towards Cr in different soils(Faculty of Graduate Studies, University of Kelaniya, 2015) Jayalath, K.G.; De Silva, R.C.L.; Deeyamulla, M.P.Phytoremediation has emerged as a plant-based and cost-effective alternative to remediate heavy metal contaminated soils. Although this technique is widely known, a significant study has not been reported yet to find out a potentially capable plant to clean Cr contaminated soils. In studies carried out by our group, six plant species (Vernonia cinerea, Tridax procumbens, Sphagnaticola trilobata, Talinum triangulare, Clitoria ternatea and Vernonia zeylanica) have been tested under Cr contaminated conditions and identified T. triangulare (Ceylon spinach) with comparatively higher tolerance to Cr with relatively higher biomass than other plants under contaminated conditions. The aim of this study was to compare the phytoremediation potential of T. triangulare towards Cr for various soil types under Cr contamination conditions. Pot experiments were carried out using four different types of soils (sand, loamy sand, clay and laterite) under Cr contamination conditions (treatments with 200 and 300 mg of Cr/ kg dry soil). Plants were harvested at 60 days of growth and Cr uptake by plant shoot and root were separately analysed by atomic absorption spectrometry. The Cr uptake by T. triangulare under different soil types with maximum contaminated conditions of Cr (300 mg/kg) were analysed (ANOVA, p < 0.05) and showed no significant difference between loamy sand and sandy soil with the mean value of 109.30 (±18.45) mg kg- 1 and 136.00 (±34.70) mg kg-1 respectively and also no significant difference between Laterite and Clay with the mean value of 36.26 (±6.12) mg kg-1 and 43.44 (±4.29) mg kg-1 respectively. The results of this study indicated that, Cr uptake capacity and the tolerability of T. triangulare significantly change with soil types. Even though T. triangulare shows to be capable of habituation in different soils, its Cr uptake capacities varies significantly. T. triangulare shows potential of being introduced to different terrestrial environments to remediate Cr. However, future study of the plant in different soil environments is suggested.Item Determination of current lead concentration in human blood by human biomonitoring in selected Sri Lankan population(Faculty of Graduate Studies, University of Kelaniya, 2015) Amaranayaka, K.K.K.H.; Deeyamulla, M.P.; Gunasekara, K.A.D.C.Lead contamination of human blood from occupational origin and vehicle emission is a cause for concern because of its potential accumulation ability in the environment and in living organisms leading to long term toxic effects. This study was aimed to assess the concentration of lead in blood of different groups exposed to different occupational conditions. Groups were selected based on the hypothesis that concentration of lead in blood may vary according to the type of exposure. Blood lead levels in students, drivers and workers of University of Kelaniya, motorcyclists and fuel station attendants in Kiribathgoda city area were studied. All other groups except fuel station attendants expose to vehicle smoke during their occupation and travelling. But fuel station attendants expose to vehicle smoke and gasoline vapors excessively during their duration of occupation than others. Some of the general population selected from a rural area who are least exposed to vehicle emissions and any occupational condition were used as the control group. A questionnaire was given to each volunteer that participated in the study to obtain the type and duration of exposure to check whether there is any correlation with lead level in blood to that parameters. Venous blood was obtained by a trained nurse and concentration of lead was determined by graphite furnace atomic absorption spectrophotometer after a microwave digestion. All analyzed groups except control group contained elevated level of lead in blood than the WHO recommended maximum level. Statistical analysis were carried out to identify the correlation between elevated level of lead in blood with the type of the exposure and the duration of the exposure. Statistical analysis revealed that lead level in blood is significantly different in each study group. Blood lead levels are found to be in, students (102.58 ± 18.50 μg L-1), drivers (208.50 ± 86.70 μg L-1) and workers (124.18 ± 27.05 μg L-1) of University of Kelaniya, motorcyclists (115.34 ± 15.30 μg L-1) and fuel station attendants (220.00 ± 65.90 μg L-1). It was also observed that individuals who smoke cigarettes had extremely high levels of lead in blood with respect to non-smokers within a same study group.Item Characterization of trace metal concentration (Al, Fe, Mn, Cu, Zn, Pb) of bulk precipitation in Kandy district, Sri Lanka(Faculty of Graduate Studies, University of Kelaniya, 2015) Liyandeniya, A.B.; Priyantha, N.; Deeyamulla, M.P.; Wickramasinghe, W.G.R.C.The atmospheric precipitation is an important phenomenon in which pollutants are scavenged from the atmosphere. Wet deposition accounts for rain, fog and snow, while dry deposition is the accumulation and fallout of aerosol particles and gases without dissolution of water. It is very important to have baseline data on the chemical composition of the atmosphere to take regulatory measures to control atmospheric pollution in Sri Lanka. The main objective of this study was thus to determine selected trace metals (Al, Fe, Mn, Cu, Zn, Pb) in bulk precipitation samples collected weekly in three sampling locations, namely the University of Peradeniya premises, Polgolla and Kandy for a period of one year from August 2013 to July 2014. Trace metals were determined in filtered and preserved rainwater (bulk) samples using Graphite Furnace Atomic Absorption Spectrometer, and volume weighted mean values of selected trace metals were subsequently calculated. Kandy municipality showed the highest contamination and followed the sequence of Al > Zn > Fe > Mn > Cu > Pb and volume weighted mean concentrations of above sequence are 53.6 μg L-1, 38.0 μg L-1, 5.8 μg L-1, 5.4 μg L-1, 4.2 μg L-1, <2.0 μg L-1. Polgolla dam site also recorded some trace metal contamination following the sequence, Al > Zn > Fe > Cu > Mn > Pb and volume weighted mean concentrations of above sequence are 51.5 μg L-1, 40.5 μg L-1, 4.8 μg L-1, 2.4 μg L-1, 1.5 μg L-1, <2.0 μg L-1. Despite less industrialization and less traffic congestion, Peradeniya University premises also showed some extent of atmospheric trace metal contamination following sequence of Al > Zn > Cu > Fe > Mn > Pb and volume weighted mean concentrations of above sequence are 46.1 μg L-1, 44.3 μg L-1, 2.6 μg L-1, 1.9 μg L-1, 1.7 μg L-1, <2.0 μg L-1. Principal component analysis (PCA), used to predict possible sources for the above trace metal contaminants, indicates that Mn, Cu and Zn are originated mainly from anthropogenic activities, such as fossil fuel combustion and burning municipal waste. Al and Fe are mainly originated from natural sources as those metals are the major components of alumino-silicate based earth crust.