Displaying publications 101 - 120 of 268 in total

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  1. Cryptic species and grey zone speciation of the Barbodes binotatus complex (Teleostei, Cyprinidae) in Sundaland
    Ng CK, Tan J
    J Fish Biol, 2021 Oct;99(4):1256-1273.
    PMID: 34159593 DOI: 10.1111/jfb.14829
    Morphology-based taxonomy of freshwater fish is effective when there are representative specimens covering large regions. However, in Sundaland, where the presence of cryptic species is high, the technique has its limitations. This is compounded by uncritical descriptions of holotypes in old literature. We demonstrate the problem using Barbodes binotatus first described from an ink drawing. Several species in the Barbodes genus of Sundaland exhibit morphological similarity to B. binotatus. We applied new DNA sequences of 16S, cytochrome c oxidase subunit I (COI), cytochrome b (Cytb) and recombination-activating gene 1 (RAG1), and pigmentation markers to clarify species complex boundaries in the Malay Peninsula, namely B. aff. binotatus "Malay Peninsula", Barbodes cf. banksi and Barbodes rhombeus. Results suggest B. binotatus-like specimens in the Malay Peninsula are B. rhombeus based on a threshold of 3% COI genetic divergence. B. aff. binotatus recorded in Sumatra, Borneo and the Philippines are likely valid but undescribed species. However, if the 2% COI threshold is applied, some populations in the northern Malay Peninsula would qualify as new and undescribed species. The implications of the 2% threshold and the likelihood of "grey zone" incipient populations are discussed. We further found a rapid visual method, not reported previously, to delineate B. aff. binotatus and B. cf. banksi, but it requires further validation. Additionally, we offer fresh perspectives by discussing the roles of biological species concept, morphological species concept, genetic species concept and mate recognition concept in the B. binotatus complex. Our findings reinforce the standpoint that species delineation is not entirely a binary process, but there is a spectrum to consider, especially in biogeography intersection regions.
    Matched MeSH terms: Fresh Water
  2. Potential biomarker of phenol toxicity in freshwater fish C. mrigala: Serum cortisol, enzyme acetylcholine esterase and survival organ gill
    Muthukumaravel K, Kanagavalli V, Pradhoshini KP, Vasanthi N, Santhanabharathi B, Alam L, et al.
    Comp Biochem Physiol C Toxicol Pharmacol, 2023 Jan;263:109492.
    PMID: 36283648 DOI: 10.1016/j.cbpc.2022.109492
    In this modern industrialized era of large-scale production of agrochemicals, various emerging contaminants form the main components of waste water and sludge in most of the developing countries of the world. In this concern, phenol- an inevitable and alarming chemical pollutant in aquatic ecosystem, gains a speedy access into the water bodies as an industrial by-product. Though the detrimental effects of phenol have been studied in various aspects of aquatic life, current study is an initiative to unravel the toxic effects of phenol at molecular level in Cirrhinus mrigala. Plasma cortisol level and acetylcholine esterase activity in fish was estimated by Chemiluminescent immunoassay technique and Ellman assay respectively. Scanning electron microscopic studies were carried out to unravel the gill histopathological alterations in exposed fish. It was observed that phenol (22.32 mg/l) inhibits 50 % of acetylcholine esterase activity in brain thereby affecting the locomotion of the targeted carp. Cortisol elevated during the 7th day in exposed fish, but declined progressively on the forthcoming 21st and 28th days. Manifestations in gill encompass curling, fusion, aberrations, sloughing of gill epithelium, wider inter filamentary space and mucus coating in the primary gill filament. It concludes that the discernable deviations produced in both biochemical parameters and key organ gill can be used as a biomarker and bio-indicator respectively for assessing the existence of emerging toxicants in aquatic ecosystem.
    Matched MeSH terms: Fresh Water
  3. Salangathelphusa peractio, a new species of lowland freshwater crab from Pulau Langkawi, Peninsular Malaysia (Crustacea, Brachyura, Gecarcinucidae)
    Ng PKL
    Zookeys, 2017.
    PMID: 29134027 DOI: 10.3897/zookeys.711.20621
    A new species of lowland freshwater crab of the family Gecarcinucidae, Salangathelphusa peractio, is described from Langkawi, an island off the northwestern coast of peninsular Malaysia. Salangathelphusa peractiosp. n. can be separated from S. brevicarinata (Hilgendorf, 1882) in having a proportionately broader external orbital tooth, a distinctly concave posterolateral margin, and the terminal segment of the male first gonopod is not distinctly bent laterally outwards; and from S. anophrys (Kemp, 1923) by its more quadrate carapace and the terminal segment of the male first gonopod possessing a relatively longer and less curved distal part. This is sixth wholly freshwater brachyuran species known from the island.
    Matched MeSH terms: Fresh Water
  4. Fulltext Status of the undisturbed mangroves at Brunei Bay, East Malaysia: a preliminary assessment based on remote sensing and ground-truth observations
    Satyanarayana B, M Muslim A, Izzaty Horsali NA, Mat Zauki NA, Otero V, Nadzri MI, et al.
    PeerJ, 2018;6:e4397.
    PMID: 29479500 DOI: 10.7717/peerj.4397
    Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite-ALOS) and ground-truth (Point-Centred Quarter Method-PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such asNypa fruticans,Rhizophora apiculata,Sonneratia caseolaris,S. albaandXylocarpus granatumin the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok-suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution ofSonneratiaspp. as pioneer vegetation at shallow river mouths,N. fruticansin the areas of strong freshwater discharge,R. apiculatain the areas of strong neritic incursion andX. granatumat interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present.
    Matched MeSH terms: Fresh Water
  5. Fulltext Prevalence and quantification of Vibrio species and Vibrio parahaemolyticus in freshwater fish at hypermarket level
    Noorlis, A., Ghazali, F.M., Cheah, Y.K., Tuan Zainazor, T.C., Ponniah, J., Tunung, R., et al.
    International Food Research Journal, 2011;18(2):689-695.
    MyJurnal
    Little is known on the biosafety level of Vibrio spp. in freshwater fish in Malaysia. The purpose of this study was to investigate the prevalence and concentration of Vibrio spp. and V. parahaemolyticus in
    freshwater fish using the Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. The study was conducted on 150 samples from two types of freshwater fish commonly sold at hypermarkets, i.e. Pangasius hypophthalmus (catfish) and Oreochromis sp. (red tilapia). Sampling was done on the flesh, intestinal tract and gills of each fish. The prevalence of Vibrio spp. and V. parahaemolyticus was found to be 98.67% and 24% respectively with higher percentages detected in samples from the gills followed by the intestinal tract and flesh. Vibrio spp. was detected in almost all red tilapia and catfish samples. V. parahaemolyticus was detected in 25% of the catfish samples compared to 22.6% of red tilapia fish. The density of Vibrio spp. and V. parahaemolyticus in the samples ranged from 0 to 1.1x107 MPN/g. Although the maximum value was 1.1x107 MPN/g, most samples had microbial loads ranging from 0 to >104 MPN/g. The outcome on the biosafety assessment of Vibrio spp. and V. parahaemolyticus in freshwater fish indicates another potential source of food safety issues to consumers.
    Matched MeSH terms: Fresh Water
  6. Fulltext Lernaea cyprinacea Linnaeus, 1758 (Copepoda: Lernaeidae) infection on Betta rubra Perugia, 1893 (Anabantiformes: Osphronemidae) from Aceh Province, Indonesia
    Nur FM, Batubara AS, Fadli N, Rizal S, Siti-Azizah MN, Wilkes M, et al.
    Rev Bras Parasitol Vet, 2022;31(1):e020421.
    PMID: 35293430 DOI: 10.1590/S1984-29612022015
    Betta rubra is an ornamental freshwater fish endemic to northern Sumatra, Indonesia. The B. rubra population has decreased in recent decades, and is classified as an endangered species in the IUCN Red List. This study aims to report for the first time infection by L. cyprinacea in B. rubra harvested from the Aceh Besar region of Indonesia. The fish samples were obtained from the Cot Bira tributaries, Aceh Besar District, Indonesia from January to December 2020. The results showed that the parasite infected 6 out of 499 samples in August and September, with a prevalence and intensity rate of 1% and 2 parasites/fish, respectively. The eyes and pectoral fins were the common infection sites. Despite B. rubra is not an optimal host (small size) for the parasite, this parasite might serve as additional threatening factors for the endangered B. rubra fish population.
    Matched MeSH terms: Fresh Water
  7. Fulltext Sexual dimorphism in shell size of the land snail Leptopoma perlucidum (Caenogastropoda: Cyclophoridae)
    Phung CC, Choo MH, Liew TS
    PeerJ, 2022;10:e13501.
    PMID: 35651743 DOI: 10.7717/peerj.13501
    Sexual dimorphism in the shell size and shape of land snails has been less explored compared to that of other marine and freshwater snail taxa. This study examined the differences in shell size and shape across both sexes of Leptopoma perlucidum land snails. We collected 84 land snails of both sexes from two isolated populations on two islands off Borneo. A total of five shell size variables were measured: (1) shell height, (2) shell width, (3) shell spire height, (4) aperture height, and (5) aperture width. We performed frequentist and Bayesian t-tests to determine if there was a significant difference between the two sexes of L. perlucidum on each of the five shell measurements. Additionally, the shell shape was quantified based on nine landmark points using the geometric morphometric approach. We used generalised Procrustes and principal component analyses to test the effects of sex and location on shell shape. The results showed that female shells were larger than male shells across all five measurements (all with p-values < 0.05), but particularly in regards to shell height and shell width. Future taxonomic studies looking to resolve the Leptopoma species' status should consider the variability of shell size caused by sexual dimorphism.
    Matched MeSH terms: Fresh Water
  8. Microplastic concentrations in river water and bed sediments in a tropical river: implications for water quality monitoring
    Chen HL, Selvam SB, Ting KN, Gibbins CN
    Environ Monit Assess, 2023 Jan 18;195(2):307.
    PMID: 36652034 DOI: 10.1007/s10661-022-10856-5
    Recent increase in awareness of the extent of microplastic contamination in marine and freshwater systems has heightened concerns over the ecological and human health risks of this ubiquitous material. Assessing risks posed by microplastic in freshwater systems requires sampling to establish contamination levels, but standard sampling protocols have yet to be established. An important question is whether sampling and assessment should focus on microplastic concentrations in the water or the amount deposited on the bed. On three dates, five replicated water and bed sediment samples were collected from each of the eight sites along the upper reach of the Semenyih River, Malaysia. Microplastics were found in all 160 samples, with mean concentrations of 3.12 ± 2.49 particles/L in river water and 6027.39 ± 16,585.87 particles/m2 deposited on the surface of riverbed sediments. Fibres were the dominant type of microplastic in all samples, but fragments made up a greater proportion of the material on the bed than in the water. Within-site variability in microplastic abundance was high for both water and bed sediments, and very often greater than between-site variability. Patterns suggest that microplastic accumulation on the bed is spatially variable, and single samples are therefore inadequate for assessing bed contamination levels at a site. Sites with the highest mean concentrations in samples of water were not those with the highest concentrations on the bed, indicating that monitoring based only on water samples may not provide a good picture of either relative or absolute bed contamination levels, nor the risks posed to benthic organisms.
    Matched MeSH terms: Fresh Water
  9. A bibliometric analysis of green technologies applied to water and wastewater treatment
    Niknejad N, Nazari B, Foroutani S, Hussin ARBC
    Environ Sci Pollut Res Int, 2023 Jun;30(28):71849-71863.
    PMID: 35091956 DOI: 10.1007/s11356-022-18705-1
    Freshwater scarcity, a problem that has arisen particularly as a result of the progressive environmental damage caused by human consumption patterns, is strongly associated with a loss of living quality and a drop in global socioeconomic development. Wastewater treatment is one of the measures being taken to mitigate the current situation. However, the majority of existing treatments employ chemicals that have harmful environmental consequences and low effectiveness and are prohibitively expensive in most countries. Therefore, to increase water supplies, more advanced and cost-effective water treatment technologies are required to be developed for desalination and water reuse purposes. Green technologies have been highlighted as a long-term strategy for conserving natural resources, reducing negative environmental repercussions, and boosting social and economic growth. Thus, a bibliometric technique was applied in this study to identifying prominent green technologies utilised in water and wastewater treatment by analysing scientific publications considering authors, keywords, and countries. To do this, the VOSviewer software and Bibliometrix R Package software were employed. The results of this study revealed that constructed wetlands and photocatalysis are two technologies that have been considered as green technologies applicable to the improvement of water and wastewater treatment processes in most scientific articles.
    Matched MeSH terms: Fresh Water
  10. The protective effect of nano calcium produced from freshwater clam shells on the histopathological overview of the liver and kidneys of mice exposed to mercury toxins
    Srie Rahayu SY, Aminingsih T, Fudholi A
    J Trace Elem Med Biol, 2022 May;71:126963.
    PMID: 35231878 DOI: 10.1016/j.jtemb.2022.126963
    BACKGROUND AND AIM: Freshwater clam shells nanoparticles powder is one of the uses of freshwater clams that can manufacture instant granular mineral supplements. This product can be used as a supplement to detoxify heavy metal toxins, such as Mercury. Mercury is an element that is detectable in all environmental media. Adults and children receive the most Mercury from food, air, and water intake. The majority of Mercury in the environment comes from the waste from mining activities and the metal industry. Mercury was found widely in the biosphere and is known as a dangerous hepatotoxicant. This study aimed to describe the hepatoprotective role of nano minerals (Ca, Mg, and Zn) produced from freshwater clam shells against mercury acetate poisoning in mice.

    MATERIAL AND METHODS: The mice were divided randomly into a control group (aqua bidest and mercury acetate) and an experimental group for this purpose. The experimental mice group was given orally nano Ca supplementation in three dose groups (9 mg, 18 mg, and 27 mg/200 g animal body weight) once a day for 21 consecutive days. The mice are then given mercury acetate (1300 µg/200 g animal body weight intraperitoneally) on the 21st day. One hour after giving the nano Ca supplement, the mice's blood was taken. Liver and kidney were autopsied two days later to check quantitative and qualitative changes caused by mercury concentrations in liver and kidney histopathologies.

    RESULTS: The results demonstrated the importance of nano Ca supplementation before mercury acetate induction, which has been shown to reduce necrotic depletion and hepatocyte degeneration.

    CONCLUSION: Nano Ca supplementation has decreased the concentration of Hg in the blood of mice so that it can be used as a potential health supplement to detoxify mercury toxins.

    Matched MeSH terms: Fresh Water
  11. Fish-associated Streptococcus agalactiae ST283: first human cases reported from Malaysia
    Zohari Z, Barkham T, Mohamad Maswan N, Chen SL, Muthanna A, Lee KW, et al.
    J Med Microbiol, 2023 Jun;72(6).
    PMID: 37389575 DOI: 10.1099/jmm.0.001729
    In South East Asia, Streptococcus agalactiae ST283 causes sepsis in healthy adults. Raw freshwater fish consumption is the only known risk factor. These two case reports are the first from Malaysia. Although they cluster with Singapore ST283, the epidemiology is complicated by the flow of people and fish across borders.
    Matched MeSH terms: Fresh Water
  12. Fulltext HDTO-DeepAR: A novel hybrid approach to forecast surface water quality indicators
    Singh RB, Patra KC, Pradhan B, Samantra A
    J Environ Manage, 2024 Feb 14;352:120091.
    PMID: 38228048 DOI: 10.1016/j.jenvman.2024.120091
    Water is a vital resource supporting a broad spectrum of ecosystems and human activities. The quality of river water has declined in recent years due to the discharge of hazardous materials and toxins. Deep learning and machine learning have gained significant attention for analysing time-series data. However, these methods often suffer from high complexity and significant forecasting errors, primarily due to non-linear datasets and hyperparameter settings. To address these challenges, we have developed an innovative HDTO-DeepAR approach for predicting water quality indicators. This proposed approach is compared with standalone algorithms, including DeepAR, BiLSTM, GRU and XGBoost, using performance metrics such as MAE, MSE, MAPE, and NSE. The NSE of the hybrid approach ranges between 0.8 to 0.96. Given the value's proximity to 1, the model appears to be efficient. The PICP values (ranging from 95% to 98%) indicate that the model is highly reliable in forecasting water quality indicators. Experimental results reveal a close resemblance between the model's predictions and actual values, providing valuable insights for predicting future trends. The comparative study shows that the suggested model surpasses all existing, well-known models.
    Matched MeSH terms: Fresh Water
  13. Leaf and twig traits predict habitat adaptation and demographic strategies in tropical freshwater swamp forest trees
    Lam WN, Huang J, Tay AHT, Sim HJ, Chan PJ, Lim KE, et al.
    New Phytol, 2024 Aug;243(3):881-893.
    PMID: 38840520 DOI: 10.1111/nph.19876
    Differences in demographic and environmental niches facilitate plant species coexistence in tropical forests. However, the adaptations that enable species to achieve higher demographic rates (e.g. growth or survival) or occupy unique environmental niches (e.g. waterlogged conditions) remain poorly understood. Anatomical traits may better predict plant environmental and demographic strategies because they are direct measurements of structures involved in these adaptations. We collected 18 leaf and twig traits from 29 tree species in a tropical freshwater swamp forest in Singapore. We estimated demographic parameters of the 29 species from growth and survival models, and degree of association toward swamp habitats. We examined pairwise trait-trait, trait-demography and trait-environment links while controlling for phylogeny. Leaf and twig anatomical traits were better predictors of all demographic parameters than other commonly measured leaf and wood traits. Plants with wider vessels had faster growth rates but lower survival rates. Leaf and spongy mesophyll thickness predicted swamp association. These findings demonstrate the utility of anatomical traits as indicators of plant hydraulic strategies and their links to growth-mortality trade-offs and waterlogging stress tolerance that underlie species coexistence mechanisms in tropical forest trees.
    Matched MeSH terms: Fresh Water
  14. Fulltext Freshwater-borne bacteria isolated from a Malaysian rainforest waterfall exhibiting quorum sensing properties
    Tan WS, Yunos NY, Tan PW, Mohamad NI, Adrian TG, Yin WF, et al.
    Sensors (Basel), 2014;14(6):10527-37.
    PMID: 24932870 DOI: 10.3390/s140610527
    One obvious requirement for concerted action by a bacterial population is for an individual to be aware of and respond to the other individuals of the same species in order to form a response in unison. The term "quorum sensing" (QS) was coined to describe bacterial communication that is able to stimulate expression of a series of genes when the concentration of the signaling molecules has reached a threshold level. Here we report the isolation from aquatic environment of a bacterium that was later identified as Enterobacter sp.. Chromobacterium violaceum CV026 and Escherichia coli [pSB401] were used for preliminary screening of N-acyl homoserine lactone (AHL) production. The Enterobacter sp. isolated was shown to produce two types of AHLs as confirmed by analysis using high resolution tandem mass spectrometry. To the best of our knowledge, this is the first documentation of an Enterobacter sp. that produced both 3-oxo-C6-HSL and 3-oxo-C8-HSL as QS signaling molecules.
    Matched MeSH terms: Fresh Water/microbiology*
  15. Fulltext Waterborne parasites: a current status from the Philippines
    Onichandran S, Kumar T, Salibay CC, Dungca JZ, Tabo HA, Tabo N, et al.
    Parasit Vectors, 2014;7:244.
    PMID: 24885105 DOI: 10.1186/1756-3305-7-244
    Despite the amount of awareness created, waterborne disease still poses threat, especially in developing countries. Due to the scarcity of reported data on waterborne parasites, the consumption of unsafe water prolongs. Thus, the occurrences of waterborne parasites from various samples were investigated from one of the Southeast Asian country, the Philippines.
    Matched MeSH terms: Fresh Water/parasitology*
  16. Application of chemometrics in understanding the spatial distribution of human pharmaceuticals in surface water
    Al-Odaini NA, Zakaria MP, Zali MA, Juahir H, Yaziz MI, Surif S
    Environ Monit Assess, 2012 Nov;184(11):6735-48.
    PMID: 22193630 DOI: 10.1007/s10661-011-2454-3
    The growing interest in the environmental occurrence of veterinary and human pharmaceuticals is essentially due to their possible health implications to humans and ecosystem. This study assesses the occurrence of human pharmaceuticals in a Malaysian tropical aquatic environment taking a chemometric approach using cluster analysis, discriminant analysis and principal component analysis. Water samples were collected from seven sampling stations along the heavily populated Langat River basin on the west coast of peninsular Malaysia and its main tributaries. Water samples were extracted using solid-phase extraction and analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for 18 pharmaceuticals and one metabolite, which cover a range of six therapeutic classes widely consumed in Malaysia. Cluster analysis was applied to group both pharmaceutical pollutants and sampling stations. Cluster analysis successfully clustered sampling stations and pollutants into three major clusters. Discriminant analysis was applied to identify those pollutants which had a significant impact in the definition of clusters. Finally, principal component analysis using a three-component model determined the constitution and data variance explained by each of the three main principal components.
    Matched MeSH terms: Fresh Water/chemistry*
  17. Time-lapse resistivity investigation of salinity changes at an ex-promontory land: a case study of Carey Island, Selangor, Malaysia
    Tajul Baharuddin MF, Taib S, Hashim R, Zainal Abidin MH, Ishak MF
    Environ Monit Assess, 2011 Sep;180(1-4):345-69.
    PMID: 21136290 DOI: 10.1007/s10661-010-1792-x
    Time-lapse resistivity measurements and groundwater geochemistry were used to study salinity effect on groundwater aquifer at the ex-promontory-land of Carey Island in Malaysia. Resistivity was measured by ABEM Terrameter SAS4000 and ES10-64 electrode selector. Relationship between earth resistivity and total dissolved solids (TDS) was derived, and with resistivity images, used to identify water types: fresh (ρ ( e ) > 6.5 Ω m), brackish (3 Ω m < ρ ( e ) < 6.5 Ω m), or saline (ρ ( e ) < 3 Ω m). Long-term monitoring of the studied area's groundwater quality via measurements of its time-lapse resistivity showed salinity changes in the island's groundwater aquifers not conforming to seawater-freshwater hydraulic gradient. In some aquifers far from the coast, saline water was dominant, while in some others, freshwater 30 m thick showed groundwater potential. Land transformation is believed to have changed the island's hydrogeology, which receives saltwater pressure all the time, limiting freshwater recharge to the groundwater system. The time-lapse resistivity measurements showed active salinity changes at resistivity-image bottom moving up the image for two seasons' (wet and dry) conditions. The salinity changes are believed to have been caused by incremental tide passing through highly porous material in the active-salinity-change area. The study's results were used to plan a strategy for sustainable groundwater exploration of the island.
    Matched MeSH terms: Fresh Water/chemistry*
  18. Molecular detection of Giardia contamination in water bodies in a zoo
    Lim YA, Lai MM, Mahdy MA, Mat Naim HR, Smith HV
    Environ Res, 2009 Oct;109(7):857-9.
    PMID: 19664767 DOI: 10.1016/j.envres.2009.07.007
    We used a combined microscopy-molecular approach to determine the occurrence and identities of waterborne Giardia sp. cysts isolated from 18 separate, 10l grab samples collected from a Malaysian zoo. Microscopy revealed that 17 of 18 samples were Giardia cyst positive with concentrations ranging from 1 to 120 cysts/l. Nine (52.9%) of the 17 cyst positive samples produced amplicons of which 7 (77.8%) could be sequenced. Giardia duodenalis assemblage A (6 of 7) and assemblage B (1 of 7), both infectious to humans, were identified at all sampling sites at the zoo. The presence of human infectious cysts raises public health issues, and their occurrence, abundance and sources should be investigated further. In this zoo setting, our data highlight the importance of incorporating environmental sampling (monitoring) in addition to routine faecal examinations to determine veterinary and public health risks, and water monitoring should be considered for inclusion as a separate element in hazard analysis, as it often has a historical (accumulative) connotation.
    Matched MeSH terms: Fresh Water/parasitology*
  19. Study of evaluation of groundwater in Gadilam basin using hydrogeochemical and isotope data
    Prasanna MV, Chidambaram S, Shahul Hameed A, Srinivasamoorthy K
    Environ Monit Assess, 2010 Sep;168(1-4):63-90.
    PMID: 19609693 DOI: 10.1007/s10661-009-1092-5
    Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mines and other industrial complexes. It is also due to extensive depressurization of Cuddalore aquifer, and bore wells for New Veeranam Scheme are constructed downstream of the basin. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemistry. Chemical parameters of groundwater such as pH, electrical conductivity, total dissolved solids, sodium (Na(+)), potassium (K(+)), calcium (Ca(+)), magnesium (Mg(+)), bicarbonate (HCO(-)(3)), sulfate (SO(-)(4)), phosphate (PO(-)(4)), and silica (H(4)SiO(4)) were determined. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock-water interaction with significant evaporation prevails in hard rock region.
    Matched MeSH terms: Fresh Water/chemistry*
  20. Evaluation of groundwater quality and its suitability for drinking and agricultural use in Thanjavur city, Tamil Nadu, India
    Nagarajan R, Rajmohan N, Mahendran U, Senthamilkumar S
    Environ Monit Assess, 2010 Dec;171(1-4):289-308.
    PMID: 20072811 DOI: 10.1007/s10661-009-1279-9
    As groundwater is a vital source of water for domestic and agricultural activities in Thanjavur city due to lack of surface water resources, groundwater quality and its suitability for drinking and agricultural usage were evaluated. In this study, 102 groundwater samples were collected from dug wells and bore wells during March 2008 and analyzed for pH, electrical conductivity, temperature, major ions, and nitrate. Results suggest that, in 90% of groundwater samples, sodium and chloride are predominant cation and anion, respectively, and NaCl and CaMgCl are major water types in the study area. The groundwater quality in the study site is impaired by surface contamination sources, mineral dissolution, ion exchange, and evaporation. Nitrate, chloride, and sulfate concentrations strongly express the impact of surface contamination sources such as agricultural and domestic activities, on groundwater quality, and 13% of samples have elevated nitrate content (>45 mg/l as NO(3)). PHREEQC code and Gibbs plots were employed to evaluate the contribution of mineral dissolution and suggest that mineral dissolution, especially carbonate minerals, regulates water chemistry. Groundwater suitability for drinking usage was evaluated by the World Health Organization and Indian standards and suggests that 34% of samples are not suitable for drinking. Integrated groundwater suitability map for drinking purposes was created using drinking water standards based on a concept that if the groundwater sample exceeds any one of the standards, it is not suitable for drinking. This map illustrates that wells in zones 1, 2, 3, and 4 are not fit for drinking purpose. Likewise, irrigational suitability of groundwater in the study region was evaluated, and results suggest that 20% samples are not fit for irrigation. Groundwater suitability map for irrigation was also produced based on salinity and sodium hazards and denotes that wells mostly situated in zones 2 and 3 are not suitable for irrigation. Both integrated suitability maps for drinking and irrigation usage provide overall scenario about the groundwater quality in the study area. Finally, the study concluded that groundwater quality is impaired by man-made activities, and proper management plan is necessary to protect valuable groundwater resources in Thanjavur city.
    Matched MeSH terms: Fresh Water/chemistry*
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