Displaying publications 141 - 160 of 509 in total

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  1. Fulltext Congenital urethrocutaneous fistula: an interesting case
    Roger, A.I., Rachel, Anne J.
    Journal of Surgical Academia, 2014;4(2):45-47.
    MyJurnal
    A congenital urethrocutaneous fistula is a rare anomaly which was first described in 1962 by Gupta. Clinically, children present when their guardian is alarmed by either frequent urinary dribbling or unusual stream when they pass urine. This congenital anomaly can present in isolation or be accompanied by a chordee, hypospadia and anorectal malformations in a newborn. The surgical management will either be a primary repair of the fistula or converting it to a hypospadia before proceeding with a single or staged hypospadia repair. Surgical technique will depend on the local tissue factors and associated anomalies.
    Matched MeSH terms: Rivers
  2. Microplastics pollution in different aquatic environments and biota: A review of recent studies
    Rezania S, Park J, Md Din MF, Mat Taib S, Talaiekhozani A, Kumar Yadav K, et al.
    Mar Pollut Bull, 2018 Aug;133:191-208.
    PMID: 30041307 DOI: 10.1016/j.marpolbul.2018.05.022
    Microplastics (MPs) are generated from plastic and have negative impact to our environment due to high level of fragmentation. They can be originated from various sources in different forms such as fragment, fiber, foam and so on. For detection of MPs, many techniques have been developed with different functions such as microscopic observation, density separation, Raman and FTIR analysis. Besides, due to ingestion of MPs by wide range of marine species, research on the effect of this pollution on biota as well as human is vital. Therefore, we comprehensively reviewed the occurrence and distribution of MPs pollution in both marine and freshwater environments, including rivers, lakes and wastewater treatment plants (WWTPs). For future studies, we propose the development of new techniques for sampling MPs in aquatic environments and biota and recommend more research regarding MPs release by WWTPs.
    Matched MeSH terms: Rivers
  3. Rapid shifts in methanotrophic bacterial communities mitigate methane emissions from a tropical hydropower reservoir and its downstream river
    Reis PCJ, Ruiz-González C, Crevecoeur S, Soued C, Prairie YT
    Sci Total Environ, 2020 Dec 15;748:141374.
    PMID: 32823225 DOI: 10.1016/j.scitotenv.2020.141374
    Methane-oxidizing bacteria (MOB) present in the water column mitigate methane (CH4) emissions from hydropower complexes to the atmosphere. By creating a discontinuity in rivers, dams cause large environmental variations, including in CH4 and oxygen concentrations, between upstream, reservoir, and downstream segments. Although highest freshwater methanotrophic activity is often detected at low oxygen concentrations, CH4 oxidation in well-oxygenated downstream rivers below dams has also been reported. Here we combined DNA and RNA high-throughput sequencing with microscopic enumeration (by CARD-FISH) and biogeochemical data to investigate the abundance, composition, and potential activity of MOB taxa from upstream to downstream waters in the tropical hydropower complex Batang Ai (Malaysia). High relative abundance of MOB (up to 61% in 16S rRNA sequences and 19% in cell counts) and enrichment of stable isotopic signatures of CH4 (up to 0‰) were detected in the hypoxic hypolimnion of the reservoir and in the outflowing downstream river. MOB community shifts along the river-reservoir system reflected environmental sorting of taxa and an interrupted hydrologic connectivity in which downstream MOB communities resembled reservoir's hypolimnetic communities but differed from upstream and surface reservoir communities. In downstream waters, CH4 oxidation was accompanied by fast cell growth of particular MOB taxa. Our results suggest that rapid shifts in active MOB communities allow the mitigation of CH4 emissions from different zones of hydropower complexes, including in quickly re-oxygenated rivers downstream of dams.
    Matched MeSH terms: Rivers
  4. Fulltext Accumulation and risk assessment of heavy metals employing species sensitivity distributions in Linggi River, Negeri Sembilan, Malaysia
    Razak MR, Aris AZ, Zakaria NAC, Wee SY, Ismail NAH
    Ecotoxicol Environ Saf, 2021 Mar 15;211:111905.
    PMID: 33453636 DOI: 10.1016/j.ecoenv.2021.111905
    The constant increase of heavy metals into the aqueous environment has become a contemporary global issue of concern to government authorities and the public. The study assesses the concentration, distribution, and risk assessment of heavy metals in freshwater from the Linggi River, Negeri Sembilan, Malaysia. Species sensitivity distribution (SSD) was utilised to calculate the cumulative probability distribution of toxicity from heavy metals. The aquatic organism's toxicity data obtained from the ECOTOXicology knowledgebase (ECOTOX) was used to estimate the predictive non-effects concentration (PNEC). The decreasing sequence of hazardous concentration (HC5) was manganese > aluminium > copper > lead > arsenic > cadmium > nickel > zinc > selenium, respectively. The highest heavy metal concentration was iron with a mean value of 45.77 μg L-1, followed by manganese (14.41 μg L-1) and aluminium (11.72 μg L-1). The mean heavy metal pollution index (HPI) value in this study is 11.52, implying low-level heavy metal pollutions in Linggi River. The risk quotient (RQ) approaches were applied to assess the potential risk of heavy metals. The RQ shows a medium risk of aluminium (RQm = 0.1125) and zinc (RQm = 0.1262); a low risk of arsenic (RQm = 0.0122) and manganese (RQm = 0.0687); and a negligible risk of cadmium (RQm = 0.0085), copper (RQm = 0.0054), nickel (RQm = 0.0054), lead (RQm = 0.0016) and selenium (RQm = 0.0012). The output of this study produces comprehensive pollution risk, thus provides insights for the legislators regarding exposure management and mitigation.
    Matched MeSH terms: Rivers
  5. Prevalence and intensity of helminths among inhabitants of the Chi River and Lahanna water reservoir areas of Northeastern Thailand
    Rattanapitoon SK, Pechdee P, Boonsuya A, Meererksom T, Wakkhuwatapong P, Leng M, et al.
    Trop Biomed, 2020 Sep 01;37(3):730-743.
    PMID: 33612786 DOI: 10.47665/tb.37.3.730
    Helminth infections (HIs) are an important public health problem in tropical countries, and the associated problems have been neglected in rural areas of Thailand. Therefore, this study reports the prevalence and intensity of HIs among inhabitants of the Khon Sawan district, Chaiyaphum province, and Kaeng Samnam Nang district, Nakhon Ratchasima province, which are located near the Chi River and Lahanna water reservoir, northeastern Thailand. A cross-sectional descriptive study was conducted between July 31, 2018, and June 30, 2019, among rural villagers from 40 rural villages in 4 subdistricts. The participants were selected from the village enrolment list after proportional allocation of the total sample size. Faecal samples from 691 inhabitants were prepared using solvent-free faecal parasite concentrator, and helminths were then detected using a light microscope. Statistical analysis included the Chi-square test with Yates correction, and multivariable logistic regression was performed. A P-value of <0.05 was considered statistically significant. The prevalence of HIs was 2.03%. The most prevalent helminths were Opisthorchis viverrini (1.31%), followed by Strongyloides stercoralis (0.44%), Ascaris lumbricoides (0.29%), hookworm (0.15%), Teania spp. (0.15%) and one minute intestinal fluke (0.15%). Coinfections were identified in 2 cases for S. stercoralis and hookworm and 1 case for O. viverrini and S. stercoralis infection. All infected participants had a light intensity of HI. There was no significant difference between general characteristics for all HIs. The prevalence of HIs was not significantly associated with general characteristics. This study indicates that the infections result mainly from foodborne helminths and skin-penetrating nematodes. Therefore, interventions should concentrate on the personal hygiene of the population and improving sanitation to reduce HIs in this area.
    Matched MeSH terms: Rivers
  6. Spatial and Temporal Variation of Water Quality in the Bertam Catchment, Cameron Highlands, Malaysia
    Rasul MG, Islam MS, Yunus RBM, Mokhtar MB, Alam L, Yahaya FM
    Water Environ Res, 2017 Dec 01;89(12):2088-2102.
    PMID: 28087920 DOI: 10.2175/106143017X14839994522740
      The spatio-temporal variability of water quality associated with anthropogenic activities was studied for the Bertam River and its main tributaries within the Bertam Catchment, Cameron Highlands, Malaysia. A number of physico-chemical parameters of collected samples were analyzed to evaluate their spatio-temporal variability. Nonparametric statistical analysis showed significant temporal and spatial differences (p < 0.05) in most of the parameters across the catchment. Parameters except dissolved oxygen and chemical oxygen demand displayed higher values in rainy season. The higher concentration of total suspended solids was caused by massive soil erosion and sedimentation. Seasonal variations in contaminant concentrations are largely affected by precipitation and anthropogenic influences. Untreated domestic wastewater discharge as well as agricultural runoff significantly influenced the water quality. Poor agricultural practices and development activities at slope areas also affected the water quality within the catchment. The analytical results provided a basis for protection of river environments and ecological restoration in mountainous Bertam Catchment.
    Matched MeSH terms: Rivers/chemistry*
  7. New magnetic graphene-based inorganic-organic sol-gel hybrid nanocomposite for simultaneous analysis of polar and non-polar organophosphorus pesticides from water samples using solid-phase extraction
    Rashidi Nodeh H, Wan Ibrahim WA, Kamboh MA, Sanagi MM
    Chemosphere, 2017 Jan;166:21-30.
    PMID: 27681257 DOI: 10.1016/j.chemosphere.2016.09.054
    A new graphene-based tetraethoxysilane-methyltrimethoxysilane sol-gel hybrid magnetic nanocomposite (Fe3O4@G-TEOS-MTMOS) was synthesised, characterized and successfully applied in magnetic solid-phase extraction (MSPE) for simultaneous analysis of polar and non-polar organophosphorus pesticides from several water samples. The Fe3O4@G-TEOS-MTMOS nanocomposite was characterized using Fourier transform-infrared spectroscopy, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy and X-ray diffraction. Separation, determination and quantification were achieved using gas chromatography coupled with micro electron capture detector. Adsorption capacity of the sorbent was calculated using Langmuir equation. MSPE was linear in the range 100-1000 pg mL(-1) for phosphamidon and dimethoate, and 10-100 pg mL(-1) for chlorpyrifos and diazinon, with limit of detection (S/N = 3) of 19.8, 23.7, 1.4 and 2.9 pg mL(-1) for phosphamidon, dimethoate, diazinon and chlorpyrifos, respectively. The LODs obtained is well below the maximum residual level (100 pg mL(-1)) as set by European Union for pesticides in drinking water. Acceptable precision (%RSD) was achieved for intra-day (1.3-8.7%, n = 3) and inter-day (7.6-17.8%, n = 15) analyses. Fe3O4@G-TEOS-MTMOS showed high adsorption capacity (54.4-76.3 mg g(-1)) for the selected OPPs. No pesticide residues were detected in the water samples analysed. Excellent extraction recoveries (83-105%) were obtained for the spiked OPPs from tap, river, lake and sea water samples. The newly synthesised Fe3O4@G-TEOS-MTMOS showed high potential as adsorbent for OPPs analysis.
    Matched MeSH terms: Rivers
  8. Fulltext Factors influencing smoking behaviours among male adolescents In Kuantan District
    Rapeah, M.Y., Munirah, Y., Latifah, K., Faizah, K., Norsimah, S., Maryana, M., et al.
    Ann Dent, 2008;15(2):77-81.
    MyJurnal
    The aims of this study were to determine the prevalence and factors that influenced smoking behaviours among male adolescents in Kuantan, Pahang. A cross-sectional study was conducted among the form four male students in Kuantan District. Three hundred and twenty three students were randomly selected from eight secondary schools. A self-administered questionnaire was distributed to all the respondents. Almost half of the sample was smokers (45.8%) and half of them were Malays (53.1%). Students whose parents had lower level of occupation were more likely to smoke (58.8%). Among smokers, 34.5% of them smoked since primary school and a majority (91.7%) smoked 10 or less cigarettes per day. Half of them (53.4%) reported that they bought loose cigarettes and most of them used their school pocket money to purchase the cigarettes (81.7%). From the multivariate analysis, it was found that Non-Science Stream classes (OR=3.92, 95% CI= 2.10, 7.32), peers' smoking (OR=6.07, 95% CI= 2.32, 15.92), and attitude towards smoking (OR= 21.93, 95% CI= 9.71,49.51) were significantly associated with smoking habit. The prevalence of smoking among male adolescents was considerably high'in this population. It is recommended that antismoking activities in school be carried out regularly and should involve an active participation from the adolescents themselves since peers have great influence on smoking habits.
    Matched MeSH terms: Rivers
  9. New macroporous β-cyclodextrin functionalized ionic liquid polymer as an adsorbent for solid phase extraction with phenols
    Raoov M, Mohamad S, bin Abas MR, Surikumaran H
    Talanta, 2014 Dec;130:155-63.
    PMID: 25159393 DOI: 10.1016/j.talanta.2014.06.067
    Cyclodextrin-ionic liquid polymer (βCD-BIMOTs-TDI) is a new class of macroporous material and has great potential to be used as an SPE adsorbent material for extraction of phenols in river water samples. Six phenols, as model analytes, were extracted on a βCD-BIMOTs-TDI SPE cartridge, and then, eluted with 2 mL of methanol containing 1% acetic acid. The optimum experimental condition was 15 mL of sample volume (sample at pH 6) and 2 mL of methanol containing 1% acetic acid as an eluent solvent. The eluent concentration was determined by using Gas Chromatography-Flame Ionization Detector (GC-FID). Under optimized condition, high sensitivity (detection limits 0.23-0.35 µg/L) and good recoveries (87-116%) were achieved with satisfactory relative standard deviation (RSD) (0.1-1.7%). The developed βCD-BIMOTs-TDI-SPE was then compared with other adsorbents, and the obtained results showed that the βCD-BIMOTs-TDI exhibited higher extraction recovery due to the unique structure and properties. Finally, the βCD-BIMOTs-TDI was applied as a solid phase extraction sorbent for phenols determination under optimized condition, in river and tap waters, prior to the GC-FID separation.
    Matched MeSH terms: Rivers/chemistry*
  10. Fulltext Influence of Cement Replacement with Fly Ash and Ground Sand with Different Fineness on Alkali-Silica Reaction of Mortar
    Ramjan S, Tangchirapat W, Jaturapitakkul C, Chee Ban C, Jitsangiam P, Suwan T
    Materials (Basel), 2021 Mar 20;14(6).
    PMID: 33804759 DOI: 10.3390/ma14061528
    The alkali-silica reaction (ASR) is an important consideration in ensuring the long-term durability of concrete materials, especially for those containing reactive aggregates. Although fly ash (FA) has proven to be useful in preventing ASR expansion, the filler effect and the effect of FA fineness on ASR expansion are not well defined in the present literature. Hence, this study aimed to examine the effects of the filler and fineness of FA on ASR mortar expansion. FAs with two different finenesses were used to substitute ordinary Portland cement (OPC) at 20% by weight of binder. River sand (RS) with the same fineness as the FA was also used to replace OPC at the same rate as FA. The replacement of OPC with RS (an inert material) was carried out to observe the filler effect of FA on ASR. The results showed that FA and RS provided lower ASR expansions compared with the control mortar. Fine and coarse fly ashes in this study had almost the same effectiveness in mitigating the ASR expansion of the mortars. For the filler effect, smaller particles of RS had more influence on the ASR reduction than RS with coarser particles. A significant mitigation of the ASR expansion was obtained by decreasing the OPC content in the mortar mixture through its partial substitution with FA and RS.
    Matched MeSH terms: Rivers
  11. Assessing Knowledge Sharing Among Academics: A Validation of the Knowledge Sharing Behavior Scale (KSBS)
    Ramayah T, Yeap JAL, Ignatius J
    Eval Rev, 2014 Apr;38(2):160-187.
    PMID: 25015259 DOI: 10.1177/0193841X14539685
    BACKGROUND: There is a belief that academics tend to hold on tightly to their knowledge and intellectual resources. However, not much effort has been put into the creation of a valid and reliable instrument to measure knowledge sharing behavior among the academics.

    OBJECTIVES: To apply and validate the Knowledge Sharing Behavior Scale (KSBS) as a measure of knowledge sharing behavior within the academic community.

    SUBJECTS: Respondents (N = 447) were academics from arts and science streams in 10 local, public universities in Malaysia.

    MEASURES: Data were collected using the 28-item KSBS that assessed four dimensions of knowledge sharing behavior namely written contributions, organizational communications, personal interactions, and communities of practice.

    RESULTS: The exploratory factor analysis showed that the items loaded on the dimension constructs that they were supposed to represent, thus proving construct validity. A within-factor analysis revealed that each set of items representing their intended dimension loaded on only one construct, therefore establishing convergent validity. All four dimensions were not perfectly correlated with each other or organizational citizenship behavior, thereby proving discriminant validity. However, all four dimensions correlated with organizational commitment, thus confirming predictive validity. Furthermore, all four factors correlated with both tacit and explicit sharing, which confirmed their concurrent validity. All measures also possessed sufficient reliability (α > .70).

    CONCLUSION: The KSBS is a valid and reliable instrument that can be used to formally assess the types of knowledge artifacts residing among academics and the degree of knowledge sharing in relation to those artifacts.

    Matched MeSH terms: Rivers
  12. Production of N-acyl homoserine lactones by Chromobacterium haemolyticum KM2 isolated from the river water in Malaysia
    Priya K, Sulaiman J, How KY, Yin WF, Chan KG
    Arch Microbiol, 2018 Sep;200(7):1135-1142.
    PMID: 29796703 DOI: 10.1007/s00203-018-1526-y
    Quorum sensing (QS) is a term used to describe cell-to-cell communication that enables bacteria to orchestrate group behaviours according to density of bacterial cells. In Gram-negative bacteria, this signalling system is widely known to regulate a variety of different phenotypes such as antibiotic production and biofilm formation. In this study, we report the production of N-acyl homoserine lactones produced by Chromobacterium haemolyticum strain KM2, a bacterium isolated from a river water of a reserved tropical national park. Preliminary screening of QS activity using biosensor reporter assays indicated that C. haemolyticum strain KM2 produces both short- and long-chain AHLs. Analysis with high-resolution liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed the production of three AHLs by strain KM2: N-octanoyl-L-homoserine lactone (C8-HSL), N-dodecanoyl-L-homoserine lactone (C12-HSL), and N-3-oxo-dodecanoyl-L-homoserine lactone (OC12-HSL). This bacterial isolate also exhibited strong β-haemolytic activity. To the best of our knowledge, this is the first documentation of QS activity and multiple AHLs production by C. haemolyticum strain KM2.
    Matched MeSH terms: Rivers/microbiology*
  13. Occurrence of selected estrogenic compounds and estrogenic activity in surface water and sediment of Langat River (Malaysia)
    Praveena SM, Lui TS, Hamin N, Razak SQ, Aris AZ
    Environ Monit Assess, 2016 Jul;188(7):442.
    PMID: 27353134 DOI: 10.1007/s10661-016-5438-5
    The occurrence and estrogenic activities of steroid estrogens, such as the natural estrone (E1), 17β estradiol (E2), and estriol (E3), as well as the synthetic 17α-ethynylestradiol (EE2), were investigated in eight sampling points along the Langat River (Malaysia). Surface water samples were collected at 0.5 m and surface sediment 0-5 cm from the river surface. Instrument analysis of steroid estrogens was determined by UPLC-ESI-MS with an ultra-performance liquid chromatograph (Perkin Elmer FX15) coupled to a Q Trap function mass spectrophotometer (model 3200: AB Sciex). Steroid estrogen concentrations were higher in the Langat River sediments than those in its surface water. In surface water, E1 was not detected in any sampling point, E2 was only detected in two midstream sampling points (range 0-0.004 ng/L), E3 in three sampling points (range 0-0.002 ng/L), and EE2 in four sampling points (range 0-0.02 ng/L). E1 and E2 were detected in sediments from all sampling points, E3 in five sampling points, while EE2 only in one midstream sample (3.29E-4 ng/g). Sewage treatment plants, farming waste, and agricultural activities particularly present midstream and downstream were identified as potential sources of estrogens. Estrogenic activity expressed as estradiol equivalents (EEQs) was below 1 ng/L in all samples for both surface water and sediment, indicating therefore a low potential estrogenic risk to the aquatic environment. Although the health risks are still uncertain for drinking water consumers exposed to low levels of steroid estrogen concentrations, Langat River water is unacceptable for direct drinking purposes without treatment. Further studies of endocrine disruptors in Malaysian waters are highly recommended.
    Matched MeSH terms: Rivers/chemistry*
  14. Pharmaceuticals residues in selected tropical surface water bodies from Selangor (Malaysia): Occurrence and potential risk assessments
    Praveena SM, Shaifuddin SNM, Sukiman S, Nasir FAM, Hanafi Z, Kamarudin N, et al.
    Sci Total Environ, 2018 Nov 15;642:230-240.
    PMID: 29902621 DOI: 10.1016/j.scitotenv.2018.06.058
    This study investigated the occurrence of nine pharmaceuticals (amoxicillin, caffeine, chloramphenicol, ciprofloxacin, dexamethasone, diclofenac, nitrofurazone, sulfamethoxazole, and triclosan) and to evaluate potential risks (human health and ecotoxicological) in Lui, Gombak and Selangor (Malaysia) rivers using commercial competitive Enzyme-Linked Immunosorbent Assay (ELISA) kit assays. Physicochemical properties of these rivers showed the surface samples belong to Class II of Malaysian National Water Quality Standards which requires conventional treatment before consumption. All the pharmaceuticals were detected in all three rivers except for triclosan, dexamethasone and diclofenac which were not detected in few of sampling locations in these three rivers. Highest pharmaceutical concentrations were detected in Gombak river in line of being as one of the most polluted rivers in Malaysia. Ciprofloxacin concentrations were detected in all the sampling locations with the highest at 299.88 ng/L. While triclosan, dexamethasone and diclofenac concentrations were not detected in a few of sampling locations in these three rivers. All these nine pharmaceuticals were within the levels reported previously in literature. Pharmaceutical production, wastewater treatment technologies and treated sewage effluent were found as the potential sources which can be related with pharmaceuticals occurrence in surface water samples. Potential human risk assessment showed low health risk except for ciprofloxacin and dexamethasone. Instead, ecotoxicological risk assessment indicated moderate risks were present for these rivers. Nevertheless, results confirmation using instrumental techniques is needed for higher degree of specificity. It is crucial to continuously monitor the surface water bodies for pharmaceuticals using a cost-effective prioritisation approach to assess sensitive sub-populations risk.
    Matched MeSH terms: Rivers/chemistry
  15. Environmental significance and geochemical speciation of trace elements in Lower Baram River sediments
    Prabakaran K, Nagarajan R, Eswaramoorthi S, Anandkumar A, Franco FM
    Chemosphere, 2019 Mar;219:933-953.
    PMID: 30572242 DOI: 10.1016/j.chemosphere.2018.11.158
    The geochemistry and distribution of major, trace and rare earth elements (REE's) was studied in the surface sediments of the Lower Baram River during two seasons: the Monsoon (MON) and Post - monsoon (POM). The major geochemical processes controlling the distribution and mobility of major, trace and REE's in the Lower Baram River surface sediments was revealed through factor analysis. The risk assessment of major and trace element levels was studied at three specific levels; i.e. the enrichment level [Contamination Factor (Cf), with the geo-accumulation index (Igeo)], the availability level [metals bound to different fractions, risk assessment code (RAC)], and the biological toxicity level [effect range low (ERL) and effect range medium (ERM)]. The results of all the indices indicate that Cu is the element of concern in the Lower Baram River sediments. The geochemical fractionation of major and trace elements were studied through sequential extraction and the results indicated a higher concentration of Mn in the exchangeable fraction. The element of concern, Cu, was found to be highly associated in the organic bound (F4) fraction during both seasons and a change in the redox, possibly due to storms or dredging activities may stimulate the release of Cu into the overlying waters of the Lower Baram River.
    Matched MeSH terms: Rivers
  16. Geochemical behaviour and risk assessment of trace elements in a tropical river, Northwest Borneo
    Prabakaran K, Eswaramoorthi S, Nagarajan R, Anandkumar A, Franco FM
    Chemosphere, 2020 Aug;252:126430.
    PMID: 32200178 DOI: 10.1016/j.chemosphere.2020.126430
    By convention, dissolved trace elements in the river water are considered to be the fraction that passes through a 0.45 μm filter. However, several researchers have considered filtration cut-off other than 0.45 μm for the separation of dissolved trace elements from particulate fraction. Recent research indicated that trace elements could exist in particulate form as colloids and natural nanoparticles. Moreover, the trace elements in the continental dust (aerosols) constitute a significant component in their geochemical cycling. Due to their high mobility, the trace elements in the micron and sub-micron scale have biogeochemical significance in the coastal zone. In this context, this study focuses on the highly mobile fraction of trace elements in particulates (<11 μm) and dissolved form in the Lower Baram River. A factor model utilizing trace elements in the dissolved and mobile phase in the particulates (<11 μm) along with water column characteristics and the partition coefficient (Kd) of the trace elements indicated a more significant role for manganese oxyhydroxides in trace element transport. Perhaps, iron oxyhydroxides play a secondary role. The factor model further illustrated the dissolution of aluminium and authigenic clay formation. Except for Fe and Al, the contamination risk of mobile trace elements in particulates (<11 μm) together with dissolved form are within the permissible limits of the Malaysian water quality standards during monsoon (MON) and postmonsoon (POM) seasons.
    Matched MeSH terms: Rivers
  17. River and fish pollution in Malaysia: A green ergonomics perspective
    Poon WC, Herath G, Sarker A, Masuda T, Kada R
    Appl Ergon, 2016 Feb 21.
    PMID: 26911247 DOI: 10.1016/j.apergo.2016.02.009
    Human activities, such as industrial, agricultural, and domestic pursuits, discharge effluents into riverine ecological systems that contains aquatic resources, such as fish, which are also used by humans. We conducted case studies in Malaysia to investigate the impacts of these human activities on water and fish resources, as well as on human well-being from an ergonomics perspective. This research shows that a green ergonomics approach can provide us with useful insights into sustainable relationships between humans and ecology in facilitating human well-being in consideration of the overall performance of the social-ecological system. Heavy metal concentrations contained in the effluents pollute river water and contaminate fish, eventually creating significant health risks and economic costs for residents, including the polluters. The study suggests a number of policy interventions to change human behavior and achieve greater collaboration between various levels of government, academia, civil society, and businesses to help establish sustainable relationships between humans and ecology in Malaysia.
    Matched MeSH terms: Rivers
  18. Aquatic insect functional feeding groups in a mountain stream with a series of check dams in northern Thailand
    Phuchiwan Suriyawong, Elizabeth A. Bergey
    Sains Malaysiana, 2018;47:1379-1386.
    A series of check dams (or small dams in shallow streams) have been placed on many streams throughout Thailand and
    the number of them continue to increase. Check dam construction activities have been emphasized by the government
    and private sector entities over the last decade to prevent severe flood or drought due to changes in rainfall patterns. This
    study evaluated distribution of functional feeding groups (FFG) in a stream with a high density of check dams. Twelve
    sampling sites at three altitudes (500, 900 and 1500 m asl) included undammed and nearby dammed sections (above
    and below check dams) were used. Aquatic insects were collected monthly at each site for a year and categorized into
    FFG. Aquatic insect composition of undammed and above dam sites was different. Abundance within each FFG at above
    dam sites significantly differed from undammed sites. Taxonomic richness at 1500 and 900 m altitudes was decreased
    at above dam sites compared with the corresponding undammed sites, whereas above dam sites of 500 m altitude had
    higher richness than undammed site. High abundance of predators and collector-gatherers associated with reservoirs
    and fine sediment accumulation above dams, where filter-feeders were scarce. Shredder abundance varied among sites
    and was highest where leaf packs were most abundant. Scrapers were least abundant group and inconsistent with the
    dams. Distribution of FFG was similar to changes in other regulated streams. The composition of FFG reflected the
    stream ecosystem conditions through adaptation of communities to stream habitat and food resources, including those
    associated with check dam construction.
    Matched MeSH terms: Rivers
  19. The status and characteristics of eutrophication in tropical coastal water
    Peyman N, Tavakoly Sany SB, Tajfard M, Hashim R, Rezayi M, Karlen DJ
    Environ Sci Process Impacts, 2017 Aug 16;19(8):1086-1103.
    PMID: 28776620 DOI: 10.1039/c7em00200a
    A set of methodological tools was tested to assess the sensitivity of several ecological and biological indices to eutrophication while at the same time attempting to explore a linkage among pressures, classification assessment and drivers. Industrial discharges, harbor activities, natural interactions and river discharges are the pressures most related to the eutrophication process in tropical coastal water bodies. Among the eutrophication indices used, TRIX and operational indicators overestimated the eutrophication status in the study area, but EI and chl-a seems to be a rather responsive index to reflect the first stage of eutrophication. It is noteworthy that EI and chl-a showed better overall agreement with the ecological quality status (EcoQ) showing that probably it reflects the indirect relation of macrobenthic with water eutrophication in a better way. An ecological boundary of EI and chl-a from moderate to poor may be needed in order to explain the poor status of relatively eutrophic Klang Strait coastal sites.
    Matched MeSH terms: Rivers/chemistry*
  20. Fulltext Status of water quality subject to sand mining in the kelantan river, kelantan
    Peck Yen T, Rohasliney H
    Trop Life Sci Res, 2013 Aug;24(1):19-34.
    PMID: 24575239 MyJurnal
    This paper aimed to describe the effects of sand mining on the Kelantan River with respect to physical and chemical parameter analyses. Three replicates of water samples were collected from five stations along the Kelantan River (November 2010 until February 2011). The physical parameters included water temperature, water conductivity, dissolved oxygen (DO), pH, total dissolved solids (TDS), total suspended solids (TSS) and turbidity, whereas the chemical parameters included the concentration of nitrogen nutrients such as ammonia, nitrate and nitrite. The Kelantan River case study revealed that TSS, turbidity and nitrate contents exceed the Malaysian Interim National Water Quality Standard (INWQS) range and are significantly different between Station 1 (KK) and Station 3 (TM). Station 1 has the largest variation of TDS, TSS, turbidity and nitrogen nutrients because of sand mining and upstream logging activities. The extremely high content of TSS and the turbidity have caused poor and stressful conditions for the aquatic life in the Kelantan River.
    Matched MeSH terms: Rivers
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