Displaying publications 81 - 100 of 3940 in total

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  1. Zakaria MR, Hirata S, Fujimoto S, Hassan MA
    Bioresour Technol, 2015 Oct;193:128-34.
    PMID: 26125612 DOI: 10.1016/j.biortech.2015.06.074
    Combined pretreatment with hot compressed water and wet disk milling was performed with the aim to reduce the natural recalcitrance of oil palm biomass by opening its structure and provide maximal access to cellulase attack. Oil palm empty fruit bunch and oil palm frond fiber were first hydrothermally pretreated at 150-190° C and 10-240 min. Further treatment with wet disk milling resulted in nanofibrillation of fiber which caused the loosening of the tight biomass structure, thus increasing the subsequent enzymatic conversion of cellulose to glucose. The effectiveness of the combined pretreatments was evaluated by chemical composition changes, power consumption, morphological alterations by SEM and the enzymatic digestibility of treated samples. At optimal pretreatment process, approximately 88.5% and 100.0% of total sugar yields were obtained from oil palm empty fruit bunch and oil palm frond fiber samples, which only consumed about 15.1 and 23.5 MJ/kg of biomass, respectively.
    Matched MeSH terms: Water/chemistry*
  2. Zakaria MP, Okuda T, Takada H
    Mar Pollut Bull, 2001 Dec;42(12):1357-66.
    PMID: 11827123
    Malaysian coasts are subjected to various threats of petroleum pollution including routine and accidental oil spill from tankers, spillage of crude oils from inland and off-shore oil fields, and run-off from land-based human activities. Due to its strategic location, the Straits of Malacca serves as a major shipping lane. This paper expands the utility of biomarker compounds, hopanes, in identifying the source of tar-balls stranded on Malaysian coasts. 20 tar-ball samples collected from the east and west coast were analyzed for hopanes and polycyclic aromatic hydrocarbons (PAHs). Four of the 13 tar-ball samples collected from the west coast of Peninsular Malaysia were identified as the Middle East crude oil (MECO) based on their biomarker signatures, suggesting tanker-derived sources significantly contributing the petroleum pollution in the Straits of Malacca. The tar-balls found on the east coast seem to originate from the offshore oil platforms in the South China Sea. The presence of South East Asian crude oil (SEACO) tar-balls on the west coast carry several plausible explanations. Some of the tar-balls could have been transported via sea currents from the east coast. The tankers carrying SEACO to other countries could have accidentally spilt the oil as well. Furthermore, discharge of tank washings and ballast water from the tankers were suggested based on the abundance in higher molecular weight n-alkanes and the absence of unresolved complex mixture (UCM) in the tar-ball samples. The other possibilities are that the tar-balls may have been originated from the Sumatran oil fields and spillage of domestic oil from oil refineries in Port Dickson and Malacca. The results of PAHs analysis suggest that all the tar-ball samples have undergone various extent of weathering through evaporation, dissolution and photooxidation.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/classification
  3. Zakaria MP, Takada H, Tsutsumi S, Ohno K, Yamada J, Kouno E, et al.
    Environ Sci Technol, 2002 May 1;36(9):1907-18.
    PMID: 12026970
    This is the first publication on the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in riverine and coastal sediments in South East Asia where the rapid transfer of land-based pollutants into aquatic environments by heavy rainfall and runoff waters is of great concern. Twenty-nine Malaysian riverine and coastal sediments were analyzed for PAHs (3-7 rings) by gas chromatography mass spectrometry. Total PAHs concentrations in the sediment ranged from 4 to 924 ng/g. Alkylated homologues were abundant for all sediment samples. The ratio of the sum of methylphenanthrenes to phenanthrene (MP/P), an index of petrogenic PAHs contribution, was more than unity for 26 sediment samples and more than 3 for seven samples for urban rivers covering a broad range of locations. The MP/P ratio showed a strong correlation with the total PAHs concentrations, with an r2 value of 0.74. This ratio and all other compositional features indicated that Malaysian urban sediments are heavily impacted by petrogenic PAHs. This finding is in contrast to other studies reported in many industrialized countries where PAHs are mostly of pyrogenic origin. The MP/P ratio was also significantly correlated with higher molecular weight PAHs such as benzo[a]pyrene, suggesting unique PAHs source in Malaysia which contains both petrogenic PAHs and pyrogenic PAHs. PAHs and hopanes fingerprints indicated that used crankcase oil is one of the major contributors of the sedimentary PAHs. Two major routes of inputs to aquatic environments have been identified: (1) spillage and dumping of waste crankcase oil and (2) leakage of crankcase oils from vehicles onto road surfaces, with the subsequent washout by street runoff. N-Cyclohexyl-2-benzothiazolamine (NCBA), a molecular marker of street dust, was detected in the polluted sediments. NCBA and other biomarker profiles confirmed our hypothesis of the input from street dust contained the leaked crankcase oil. The fingerprints excluded crude oil, fresh lubricating oil, asphalt, and tire-particles as major contributors.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*
  4. Zakaria MH, Ramaiya SD, Bidin N, Syed NNF, Bujang JS
    PeerJ, 2023;11:e15496.
    PMID: 37456903 DOI: 10.7717/peerj.15496
    BACKGROUND: The social acceptability of wild freshwater macrophytes as locally consumed vegetables is widespread. Freshwater macrophytes have several uses; for example, they can be used as food for humans. This study determined the proximate composition and mineral content of three freshwater macrophyte species, i.e., Eichhornia crassipes, Limnocharis flava, and Neptunia oleracea.

    METHODS: Young shoots of E. crassipes, L. flava, and N. oleracea were collected from shallow channels of Puchong (3°00'11.89″N, 101°42'43.12″E), Ladang 10, Universiti Putra Malaysia (2°58'44.41″N, 101°42'44.45″E), and Kampung Alur Selibong, Langgar (06°5'50.9″N, 100°26'49.8″E), Kedah, Peninsular Malaysia. The nutritional values of these macrophytes were analysed by using a standard protocol from the Association of Official Analytical Chemists. Eight replicates of E. crassipes and L. flava and four replicates of N. oleracea were used for the subsequent analyses.

    RESULTS: In the proximate analysis, N. oleracea possessed the highest percentage of crude protein (29.61%) and energy content (4,269.65 cal g-1), whereas L. flava had the highest percentage of crude fat (5.75%) and ash (18.31%). The proximate composition trend for each species was different; specifically, all of the species possessed more carbohydrates and fewer crude lipids. All of the species demonstrated a similar mineral trend, with high nitrogen and potassium and lower copper contents. Nitrogen and potassium levels ranged from 12,380-40,380 mg kg-1 and from 11,212-33,276 mg kg-1, respectively, and copper levels ranged from 16-27 mg kg-1. The results showed that all three plant species, i.e., E. crassipes, N. oleracea, and L. flava are plant-based sources of macro- and micronutrient beneficial supplements for human consumption.

    Matched MeSH terms: Fresh Water/analysis
  5. Zainurin SN, Wan Ismail WZ, Mahamud SNI, Ismail I, Jamaludin J, Ariffin KNZ, et al.
    Int J Environ Res Public Health, 2022 Oct 28;19(21).
    PMID: 36360992 DOI: 10.3390/ijerph192114080
    Nowadays, water pollution has become a global issue affecting most countries in the world. Water quality should be monitored to alert authorities on water pollution, so that action can be taken quickly. The objective of the review is to study various conventional and modern methods of monitoring water quality to identify the strengths and weaknesses of the methods. The methods include the Internet of Things (IoT), virtual sensing, cyber-physical system (CPS), and optical techniques. In this review, water quality monitoring systems and process control in several countries, such as New Zealand, China, Serbia, Bangladesh, Malaysia, and India, are discussed. Conventional and modern methods are compared in terms of parameters, complexity, and reliability. Recent methods of water quality monitoring techniques are also reviewed to study any loopholes in modern methods. We found that CPS is suitable for monitoring water quality due to a good combination of physical and computational algorithms. Its embedded sensors, processors, and actuators can be designed to detect and interact with environments. We believe that conventional methods are costly and complex, whereas modern methods are also expensive but simpler with real-time detection. Traditional approaches are more time-consuming and expensive due to the high maintenance of laboratory facilities, involve chemical materials, and are inefficient for on-site monitoring applications. Apart from that, previous monitoring methods have issues in achieving a reliable measurement of water quality parameters in real time. There are still limitations in instruments for detecting pollutants and producing valuable information on water quality. Thus, the review is important in order to compare previous methods and to improve current water quality assessments in terms of reliability and cost-effectiveness.
    Matched MeSH terms: Water Pollution; Water Quality*
  6. Zainudin MHM, Hassan MA, Tokura M, Shirai Y
    Bioresour Technol, 2013 Nov;147:632-635.
    PMID: 24012093 DOI: 10.1016/j.biortech.2013.08.061
    The composting of lignocellulosic oil palm empty fruit bunch (OPEFB) with continuous addition of palm oil mill (POME) anaerobic sludge which contained nutrients and indigenous microbes was studied. In comparison to the conventional OPEFB composting which took 60-90 days, the rapid composting in this study can be completed in 40 days with final C/N ratio of 12.4 and nitrogen (2.5%), phosphorus (1.4%), and potassium (2.8%), respectively. Twenty-seven cellulolytic bacterial strains of which 23 strains were closely related to Bacillus subtilis, Bacillus firmus, Thermobifida fusca, Thermomonospora spp., Cellulomonas sp., Ureibacillus thermosphaericus, Paenibacillus barengoltzii, Paenibacillus campinasensis, Geobacillus thermodenitrificans, Pseudoxanthomonas byssovorax which were known as lignocellulose degrading bacteria and commonly involved in lignocellulose degradation. Four isolated strains related to Exiguobacterium acetylicum and Rhizobium sp., with cellulolytic and hemicellulolytic activities. The rapid composting period achieved in this study can thus be attributed to the naturally occurring cellulolytic and hemicellulolytic strains identified.
    Matched MeSH terms: Waste Water*
  7. Zainuddin N, Ahmad I, Zulfakar MH, Kargarzadeh H, Ramli S
    Carbohydr Polym, 2021 Feb 15;254:117401.
    PMID: 33357890 DOI: 10.1016/j.carbpol.2020.117401
    Low bioavailability and poor water solubility have limited the utilization of curcumin in conventional dosing methods. As an alternative, microemulsions as drug carrier can improve curcumin delivery. A cetyltrimethylammonium bromide-nanocrystalline cellulose (CTAB-NCC)-based microemulsion was developed and its potential use as a topical delivery method for curcumin was investigated. The effect of microemulsion's particle size and its microstructure as well as the presence of the CTAB-NCC nanoparticle on the topical delivery of curcumin was studied. In vitro permeation studies showed higher penetration rate of curcumin from the oil-in-water type-microemulsions. The skin permeation profile of curcumin followed Higuchi release kinetics. Furthermore, use of the (CTAB-NCC)-based microemulsion enhanced curcumin accumulation in the skin and these system showed non cytotoxicity effect on L929 cell line. These results showed the potential of (CTAB-NCC)-based microemulsions as controlled-release topical systems for the delivery of curcumin and potentially other lipophilic drugs.
    Matched MeSH terms: Water
  8. Zainuddin N, Nair P, Razali F
    Malays Fam Physician, 2016;11(2-3):33-34.
    PMID: 28461857
    Leech is an uncommon nasal foreign body, which can cause epistaxis. It is an aquatic segmental worm living in fresh water most commonly in tropical areas. Once it is attached in the nose, it will secrete an anticoagulant enzyme named hirudin, and that will result in continuous bleeding more than from a normal wound even after it is removed. We present a case of a live leech in the nose that caused unilateral epistaxis in a patient with a recent history of jungle trekking.
    Matched MeSH terms: Fresh Water
  9. Zainuddin AH, Wee SY, Aris AZ
    Environ Geochem Health, 2020 Nov;42(11):3703-3715.
    PMID: 32488800 DOI: 10.1007/s10653-020-00604-4
    The application of organophosphorus pesticides (OPPs) increased gradually because of the rise in global food demand that triggered the agriculture sector to increase the production, leading to OPP residues in the surface water. This study elucidated the presence of OPPs and estimated its ecological risk in the riverine ecosystem of the urbanised Linggi River, Negeri Sembilan, Malaysia. The OPP concentration in surface water was determined using solid-phase extraction method and high-performance liquid chromatography coupled with diode array detection. Further, the ecological risk was estimated by using the risk quotient (RQ) method. The three OPPs, i.e. chlorpyrifos, diazinon, and quinalphos were detected with mean concentrations of 0.0275 µg/L, 0.0328 µg/L, and 0.0362 µg/L, respectively. The OPPs were at high risk (in general and worst cases) under acute exposure. The estimated risk of diazinon was observed as medium for general (RQm = 0.5857) and high for worst cases (RQex = 4.4678). Notably, the estimated risk for chlorpyrifos was high for both general and worst cases (RQm = 1.9643 and RQex = 11.5643) towards the aquatic ecosystem of the Linggi River. Chronic risk of quinalphos remains unknown because of the absence of toxicity endpoints. This study presented clear knowledge regarding OPP contamination and possible risk for aquatic ecosystems. Hence, OPPs should be listed as one of the main priority contaminants in pesticide mitigation management in the future.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/toxicity
  10. Zainol Z, Akhir MF, Zainol Z
    Mar Pollut Bull, 2021 Mar;164:112011.
    PMID: 33485016 DOI: 10.1016/j.marpolbul.2021.112011
    Setiu Wetland is rapidly developing into an aquaculture and agriculture hub, causing concern about its water quality condition. To address this issue, it is imperative to acquire knowledge of the spatial and temporal distributions of pollutants. Consequently, this study applied combinations of hydrodynamic and particle tracking models to identify the transport behaviour of pollutants and calculate the residence time in Setiu Lagoon. The particle tracking results indicated that the residence time in Setiu Lagoon was highly influenced by the release location, where particles released closer to the river mouth exhibited shorter residence times than those released further upstream. Despite this fact, the pulse of river discharges successfully reduced the residence time in the order of two to twelve times shorter. Under different tidal phases, the residence time during the neap tide was longer regardless of heavy rainfalls, implying the domination of tidal flow in the water renewal within the lagoon.
    Matched MeSH terms: Water Quality
  11. Zainol Z, Akhir MF, Johari A, Ali A
    Data Brief, 2021 Apr;35:106866.
    PMID: 33816725 DOI: 10.1016/j.dib.2021.106866
    This article contains water quality data collected in a shallow and narrow Setiu Lagoon during the southwest monsoon, wet period of northeast monsoon and dry period of northeast monsoon. The surface water quality parameters, which include the temperature, salinity, chlorophyll-a and nutrients (ammonia, nitrate, phosphate, and silicate) were sampled twice per day (high and low tides) at a total of eight stations. Hourly current speed and direction was obtained from mooring of two units of current meters. Compared to the Malaysia Marine Water Quality Criteria and Standard (MWQCS), nutrients in Setiu Lagoon were in Class 2. Although limited, this dataset can provide insights on the changes of water quality condition in Setiu Lagoon under the presence of anthropogenic pressures.
    Matched MeSH terms: Water; Water Quality
  12. Zainol NFM, Zainuddin AH, Looi LJ, Aris AZ, Isa NM, Sefie A, et al.
    PMID: 34071804 DOI: 10.3390/ijerph18115733
    Rapid urbanization and industrial development in the Langat Basin has disturbed the groundwater quality. The populations' reliance on groundwater sources may induce possible risks to human health such as cancer and endocrine dysfunction. This study aims to determine the groundwater quality of an urbanized basin through 24 studied hydrochemical parameters from 45 groundwater samples obtained from 15 different sampling stations by employing integrated multivariate analysis. The abundance of the major ions was in the following order: bicarbonate (HCO3-) > chloride (Cl-) > sodium (Na+) > sulphate (SO42-) > calcium (Ca2+) > potassium (K+) > magnesium (Mg2+). Heavy metal dominance was in the following order: Fe > Mn > Zn > As > Hg > Pb > Ni > Cu > Cd > Se > Sr. Classification of the groundwater facies indicated that the studied groundwater belongs to the Na-Cl with saline water type and Na-HCO3 with mix water type characteristics. The saline water type characteristics are derived from agricultural activities, while the mixed water types occur from water-rock interaction. Multivariate analysis performance suggests that industrial, agricultural, and weathering activities have contributed to groundwater contamination. The study will help in the understanding of the groundwater quality issue and serve as a reference for other basins with similar characteristics.
    Matched MeSH terms: Water Quality
  13. Zainol NA, Ming TS, Darwis Y
    Indian J Pharm Sci, 2015 12 15;77(4):422-33.
    PMID: 26664058 DOI: 10.4103/0250-474x.164785
    Cinnamon leaf oil contains a high percentage of eugenol and has antimicrobial, antioxidant and antiinflammatory properties. However, the undiluted oil can cause irritation to the skin. Therefore, the aims of this study were to develop and evaluate cinnamon leaf oil nanocream using palm oil. Nanocream base was prepared using different ratios of oil, surfactants and water. The surfactant used were mixture of Tween 80:Carbitol or Tween 80:Span 65 at different hydrophile-lipophile balance values. The pseudoternary phase diagrams were constructed to identify the nanocream base areas and the results showed that the nanocream bases using Span 65 as co-surfactant produced bigger cream area. Fifteen formulations using mixtures of Tween 80:Span 65 were further evaluated for accelerated stability test, droplet size, zeta potential, rheological properties and apparent viscosity. The nanocream base which had an average droplet size of 219 nm and had plastic flow with thixotropic behavior was selected for incorporation of 2% cinnamon leaf oil. The nanocream containing cinnamon leaf oil had the average size of 286 nm and good rheological characteristics. The in vitro release study demonstrated that eugenol as the main constituent of cinnamon leaf oil was released for about 81% in 10 h. The short-term stability study conducted for 6 months showed that the cinnamon leaf oil nanocream was stable at a temperature of 25° and thus, cinnamon leaf oil nanocream is a promising natural based preparation to be used for topical application.
    Matched MeSH terms: Water
  14. Zainol MKM, Linforth RJC, Winzor DJ, Scott DJ
    Eur Biophys J, 2021 Dec;50(8):1103-1110.
    PMID: 34611772 DOI: 10.1007/s00249-021-01572-y
    This investigation of the temperature dependence of DppA interactions with a subset of three dipeptides (AA. AF and FA) by isothermal titration calorimetry has revealed the negative heat capacity ([Formula: see text]) that is a characteristic of hydrophobic interactions. The observation of enthalpy-entropy compensation is interpreted in terms of the increased structuring of water molecules trapped in a hydrophobic environment, the enthalpic energy gain from which is automatically countered by the entropy decrease associated with consequent loss of water structure flexibility. Specificity for dipeptides stems from appropriate spacing of designated DppA aspartate and arginine residues for electrostatic interaction with the terminal amino and carboxyl groups of a dipeptide, after which the binding pocket closes to become completely isolated from the aqueous environment. Any differences in chemical reactivity of the dipeptide sidechains are thereby modulated by their occurrence in a hydrophobic environment where changes in the structural state of entrapped water molecules give rise to the phenomenon of enthalpy-entropy compensation. The consequent minimization of differences in the value of ΔG0 for all DppA-dipeptide interactions thus provides thermodynamic insight into the biological role of DppA as a transporter of all dipeptides across the periplasmic membrane.
    Matched MeSH terms: Water
  15. Zainol Abidin IZ, Fazry S, Jamar NH, Ediwar Dyari HR, Zainal Ariffin Z, Johari AN, et al.
    Sci Rep, 2020 08 25;10(1):14165.
    PMID: 32843675 DOI: 10.1038/s41598-020-70962-7
    In Malaysia, Piper sarmentosum or 'kaduk' is commonly used in traditional medicines. However, its biological effects including in vivo embryonic toxicity and tissue regenerative properties are relatively unknown. The purpose of this study was to determine zebrafish (Danio rerio) embryo toxicities and caudal fin tissue regeneration in the presence of P. sarmentosum aqueous extracts. The phytochemical components and antioxidant activity of the extract were studied using GC-MS analysis and DPPH assay, respectively. Embryo toxicity tests involving survival, heartbeat, and morphological analyses were conducted to determine P. sarmentosum extract toxicity (0-60 µg/mL); concentrations of 0-400 µg/mL of the extract were used to study tissue regeneration in the zebrafish caudal fin. The extract contained several phytochemicals with antioxidant activity and exhibited DPPH scavenging activity (IC50 = 50.56 mg/mL). Embryo toxicity assays showed that a concentration of 60 μg/mL showed the highest rates of lethality regardless of exposure time. Slower embryogenesis was observed at 40 µg/mL, with non-viable embryos first detected at 50 µg/mL. Extracts showed significant differences (p 
    Matched MeSH terms: Water
  16. Zaini NA, Harith HH, Olusesan AT, Zulkifli AH, Bakar FA, Osman A, et al.
    J Food Prot, 2010 Mar;73(3):541-6.
    PMID: 20202342
    The objective of this study was to determine the level of preservatives and microbiological loads in various brands of commercially available chili bo (paste). Fifteen different brands of chili bo obtained from the local market and hypermarkets were analyzed for pH, moisture and benzoic acid content, microbiological loads (aerobic, anaerobic, aerobic spores, and fungi), and thermophilic microorganisms. Results showed that both moisture content and pH vary among samples. The concentrations of benzoic acid detected in chili bo were found to be in the range of 537 to 5,435 mg/kg. Nine of fifteen brands were found to exceed the maximum level permitted by the Malaysian Food Law in accordance with the Codex Alimentarius (1,000 mg/kg for benzoic acid). An apparent correlation between benzoic acid concentration and microbiological loads present in the chili bo was observed. The microbiological loads were found to be relatively low in the end products containing high amounts of benzoic acid. The heat-resistant (70 to 80 degrees C) microorganisms present in chili bo were identified as Ochrobacterum tritici, Stenotrophomonas rhizophila, Microbacterium maritypicum, Roseomonas spp., CDC group II-E subgroup A, Flavimonas oryzihabitans, and Pseudomonas aeruginosa, with M. maritypicum being the most frequently found (in 9 of 15 samples) microorganism. Most of these identified microorganisms were not known to cause foodborne illnesses.
    Matched MeSH terms: Water/metabolism
  17. Zaini Hamzah, Siti Afiqah Abdul Rahman, Ahmad Saat, Siti Shahrina Agos, Zaharudin Ahmad
    MyJurnal
    The presence of 226 Ra in water is a great concern in human life since it can cause health risk to a certain extent. In the state of Kelantan, being known of its granitic area, there is a lack measurement of 226 Ra content in river water, since water is the major source of water supply. According to the INTERIM National Water Quality Standards for Malaysia (INWQS), 226 Ra activity concentration in water cannot exceed 0.1 Bq/L. For this reasons, this research was planned to carry out a systematic measurement of water along Sungai Kelantan. Liquid Scintillation Counting was used for measurement of 226 Ra in water samples from Sungai Kelantan mainly in district of Kuala Krai. In this paper, the results obtained is about 26 water samples, filtered and unfiltered, collected along Sungai Lebir, Sungai Sok and Bukit Sabah. Thus, the assessment activity concentration of 226 Ra in river water was obtained as well as annual effective dose for consumption of drinking water.
    Matched MeSH terms: Fresh Water; Water Supply; Water Quality; Drinking Water
  18. Zaini Hamzah, Nurul Latiffah Abd Rani, Ahmad Saat
    MyJurnal
    Measurement of major cation such as Na+, K+, and Ca2+ in water are normally carried out using
    AAS, ICP-OES or flame photometry. In this study, an attempt was made to measure these cations
    using Energy Dispersive X-ray Fluorescent Spectrometry (EDXRF). Hot spring s water was taken from varies hot spring in Selangor and divided into two portions that is filtered and unfiltered. 5 mL of water samples were pipette into a special liquid cups (sample holders) which has a thin mylar film underneath. The MiniPal4 XRF instrument was used in this study. The resolution for the instrument use is 145 keV with energy resolution at 5.9 keV. The spectrum of cations were analysed by using MiniPal/MiniMate software to determine the cations concentration. For K+ and Ca2+, Al-thin filter was used and default filter was used for Na+. The concentration of Na+ obtained for filtered and unfiltered samples were ranged from 38.00 to 66.05 and 43.26 to 76.95 ppm. Meanwhile, concentrations of K+ for filtered and unfiltered samples were ranged from 2.42 to 8.07 and 6.18 to 29.28 ppm. Concentrations of Ca2+ for filtered and unfiltered samples were ranged from 2.59 to 10.94 and 3.18 to 12.99 ppm.
    Matched MeSH terms: Water
  19. Zaini Hamzah, Ahmad Saat, Mohammed Kassim
    MyJurnal
    Many studies were carried out throughout the world on radon measurement in water especially drinking water for it can cause problem to human health. This study is an attempt to measure the level of radon present in water collect from rivers and lakes. Data gathered from this study provides important information about radiation levels in water at selected sites, because radon gas is the largest contributor to natural radioactive radiation exposure to humans. Exposure to radon gas can cause lung cancer. Liquid scintillation counting (LSC) has been applied to determine the activity concentration of radon ( 222 Rn) in water. Water samples were collected from, ex-mining lake in Perak, Sok River in Kelantan, Tembeling River in Pahang. Water samples were prepared in polyethylene bottles mixed with liquid scintillator and stored for 3 weeks to allow 222 Rn and its progeny to reach the equilibrium, and the activity concentrations ranged from 0.24-1.27 Bq/L, and 0.029 – 0.155 Bq/L for radon and radium respectively.
    Matched MeSH terms: Drinking Water
  20. Zaini Hamzah, Masitah Alias, Siti Afiqah Abdul Rahman, Mohamed Kassim, Ahmad Saat, Abdul Kadir Ishak
    MyJurnal
    Recently, Malaysia has taken a positive step toward providing a better water quality by introducing more water quality parameters into its Water Quality Standard. With regard to the natural radionuclides that may present in the water, 3 parameters were introduced that is gross alpha, gross beta and radium which need to be measured and cannot exceed 0.1, 1.0 and 1.0 Bq/L respectively. This study was conducted to develop a more practical method in measuring these parameters in aqueous environmental samples. Besides having a lot of former tin mining areas, some part of Malaysia is located on the granitic rock which also contributes to a certain extent the amount of natural radionuclides such as uranium and thorium. For all we know these two radionuclides are the origin of other radionuclides being produced from their decay series. The State of Kelantan was chosen as the study area, where the water samples were collected from various part of the Kelantan River. 25 liters of samples were collected, acidify to pH 2 and filtered before the analysis. Measurement of these parameters was done using liquid scintillation counter (LSC). The LSC was set up to
    the optimum discriminator level and counting was done using alpha-beta mode. The results show that gross alpha and beta can be measured using scintillation cocktail and radium and radon using extraction method. The results for gross alpha, gross beta, 222Ra and 226Ra are 0.39-6.42, 0.66-16.18, 0.40-4.65 and 0.05-0.56 Bq/L. MDA for gross alpha, gross beta and radium is 0.03, 0.08 and 0.00035 Bq/L respectively.
    Matched MeSH terms: Water; Water Pollutants, Radioactive; Water Quality
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