MyMedR

Displaying publications 1 - 20 of 508 in total

Abstract:

Sort:

Water quality variation during a strong El Niño event in 2016: a case study in Kampar River, Malaysia

Ng CK, Goh CH, Lin JC, Tan MS, Bong W, Yong CS, et al.

Environ Monit Assess, 2018 Jun 15;190(7):402.
PMID: 29904816 DOI: 10.1007/s10661-018-6784-2

El Niño and Southern Oscillation (ENSO) is a natural forcing that affects global climate patterns, thereon influencing freshwater quality and security. In the advent of a strong El Niño warming event in 2016 which induced an extreme dry weather in Malaysia, water quality variation was investigated in Kampar River which supplies potable water to a population of 92,850. Sampling points were stratified into four ecohydrological units and 144 water samples were examined from October 2015 to March 2017. The Malaysian Water Quality Index (WQI) and some supplementary parameters were analysed in the context of reduced precipitation. Data shows that prolonged dry weather, episodic and sporadic pollution incidents have caused some anomalies in dissolved oxygen (DO), total suspended solids (TSS), turbidity and ammoniacal nitrogen (AN) values recorded and the possible factors are discussed. The month of March and August 2016 recorded the lowest precipitation, but the overall resultant WQI remained acceptable. Since the occurrence of a strong El Niño event is infrequent and far between in decadal time scale, this paper gives some rare insights that may be central to monitoring and managing freshwater resource that has a crucial impact to the mass population in the region of Southeast Asia.

Matched MeSH terms: Rivers/chemistry
Water quality status of selected rivers in Kota Marudu, Sabah, Malaysia and its suitability for usage

Ahmad Zaharin Aris, Wan YL, Sarva MP, Mohd Kamil Yusoff, Muhamma Firuz Ramli, Hafizan Juahir

Sains Malaysiana, 2014;43:377-388.

The water chemistry of selected rivers in Kota Marudu, Sabah was studied based on the major ion chemistry and its suitability for drinking and irrigation purposes. Ten sampling stations were selected and water samples were collected from each station to assess its chemical properties. The physico-chemical variables including temperature, electrical conductivity (EC), total dissolved solids (TDS), salinity, dissolved oxygen (DO), pH, turbidity, ammoniacal-nitrogen (NH3-N), biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solid (TSS) were measured. The cations (K, Mg, Ca, Na) were analyzed by ICP-MS. Most of the variables were within the drinking water quality standards stipulated by the World Health Organization (WHO) and the Ministry of Health (MOH), Malaysia except for turbidity. Sodium adsorption ratio (SAR) and salinity hazard were calculated to identify the suitability of the water as irrigation water. The Wilcox diagram classifies that only 10% of samples are not suitable for the purpose of irrigation. The overall results showed that most of the rivers in Kota Marudu are still in a clean condition and suitable for drinking and irrigation purposes except for Sumbilingan River, which is considered as slightly polluted. The results are supported by the hierarchical cluster analysis as the stations were grouped into two groups; low and high pollution intensities. This preliminary result can update the baseline data of selected water quality parameters in the Kota Marudu and could serve as tool for assisting relevant government bodies in regulating the water resources policies in the future.

Matched MeSH terms: Rivers
Water quality modelling using principal component analysis and artificial neural network

Ibrahim A, Ismail A, Juahir H, Iliyasu AB, Wailare BT, Mukhtar M, et al.

Mar Pollut Bull, 2023 Feb;187:114493.
PMID: 36566515 DOI: 10.1016/j.marpolbul.2022.114493

The study investigates the latent pollution sources and most significant parameters that cause spatial variation and develops the best input for water quality modelling using principal component analysis (PCA) and artificial neural network (ANN). The dataset, 22 water quality parameters were obtained from Department of Environment Malaysia (DOE). The PCA generated six significant principal component scores (PCs) which explained 65.40 % of the total variance. Parameters for water quality variation are mainlyrelated to mineral components, anthropogenic activities, and natural processes. However, in ANN three input combination models (ANN A, B, and C) were developed to identify the best model that can predict water quality index (WQI) with very high precision. ANN A model appears to have the best prediction capacity with a coefficient of determination (R2) = 0.9999 and root mean square error (RMSE) = 0.0537. These results proved that the PCA and ANN methods can be applied as tools for decision-making and problem-solving for better managing of river quality.

Matched MeSH terms: Rivers
Water quality influences on fish occurrences in sungai Pahang, Maran district, Pahang, Malaysia

Zulkafli Abdul Rashid, Mohammad Noor Azmai Amal

Sains Malaysiana, 2018;47:1941-1951.

This study assesses the influence of water quality on fish occurrences in Sungai Pahang, Maran District, Pahang, Malaysia. Water quality and fish samplings were conducted at seven sampling sites in the district for 13 consecutive months. We used canonical correspondence analyses (CCA) to determine the influence of water quality on monthly fish species occurrences. The ranges of water quality parameters were quite high considering the measurements were made during rainy and dry seasons throughout the year. A total of 2,075 individual fish was captured which comprised of 22 different families and 65 species. Family Cyprinidae recorded the highest number of fish species of the area (27 species; 41.5%), followed by Bagridae (five species; 7.69%) and Pangasiidae (five species; 7.69%). Three fish species categorized as endangered, including Balantiocheilos melanopterus, Probarbus jullieni and Pangasianodon hypophthalmus were also collected. The collected fish species were divided into three groups (A to C), which was clearly separated in the CCA ordination diagram. The most important water quality variables for the fish occurrences in this river were pH, followed by temperature, conductivity, alkalinity and phosphate. Data analysis indicates that the occurrence of fishes were influenced by a combination of water quality parameters, but not associated with sampling month. The results present a new data from a study of fish assemblage and their habitat condition which may be important in fisheries activity and fish conservation of the river in the future.

Matched MeSH terms: Rivers
Water quality evaluation system to assess the status and the suitability of the Citarum river water to different uses

Fulazzaky MA

Environ Monit Assess, 2010 Sep;168(1-4):669-84.
PMID: 19728125 DOI: 10.1007/s10661-009-1142-z

Water quality degradation in the Citarum river will increase from the year to year due to increasing pollutant loads when released particularly from Bandung region of the upstream areas into the river without treatment. This will be facing the problems on water quality status to use for multi-purposes in the downstream areas. The water quality evaluation system is used to evaluate the available water condition that distinguishes into two categories, i.e., the water quality index (WQI) and water quality aptitude (WQA). The assessment of water quality for the Citarum river from 10 selected stations was found that the WQI situates in the bad category generally and the WQA ranges from the suitable quality for agriculture and livestock watering uses to the unsuitable for biological potential function, drinking water production, and leisure activities and sports in the upstream areas of Saguling dam generally.

Matched MeSH terms: Rivers/chemistry*
Water quality assessment and analysis of spatial patterns and temporal trends

Gazzaz NM, Yusoff MK, Juahir H, Ramli MF, Aris AZ

Water Environ Res, 2013 Aug;85(8):751-66.
PMID: 24003601

This study investigated relationships of a water quality index (WQI) with multiple water quality variables (WQVs), explored variability in water quality over time and space, and established linear and non-linear models predictive of WQI from raw WQVs. Data were processed using Spearman's rank correlation analysis, multiple linear regression, and artificial neural network modeling. Correlation analysis indicated that from a temporal perspective, the WQI, temperature, and zinc, arsenic, chemical oxygen demand, sodium, and dissolved oxygen concentrations increased, whereas turbidity and suspended solids, total solids, nitrate nitrogen (NO3-N), and biochemical oxygen demand concentrations decreased with year. From a spatial perspective, an increase with distance of the sampling station from the headwater was exhibited by 10 WQVs: magnesium, calcium, dissolved solids, electrical conductivity, temperature, NO3-N, arsenic, chloride, potassium, and sodium. At the same time, the WQI; Escherichia coli bacteria counts; and suspended solids, total solids, and dissolved oxygen concentrations decreased with distance from the headwater. Lastly, regression and artificial neural network models with high prediction powers (81.2% and 91.4%, respectively) were developed and are discussed.

Matched MeSH terms: Rivers/chemistry*
Water or sediment? Partitioning the role of water column and sediment chemistry as drivers of macroinvertebrate communities in an austral South African stream

Dalu T, Wasserman RJ, Tonkin JD, Mwedzi T, Magoro ML, Weyl OLF

Sci Total Environ, 2017 Dec 31;607-608:317-325.
PMID: 28692901 DOI: 10.1016/j.scitotenv.2017.06.267

Water pollution is a critical management issue, with many rivers and streams draining urban areas being polluted by the disposal of untreated solid waste and wastewater discharge, storm water and agricultural runoff. This has implications for biodiversity, and many rivers in the developing world are now considered compromised. We investigated benthic macroinvertebrate community structure and composition in relation to physico-chemical conditions of the water column and sediments. The study was conducted in an Austral catchment subject to both urban and agricultural pollutants in two different seasons. We assessed whether sediment characteristics were more important drivers of macroinvertebrate community composition than water column characteristics. We expected clear differences in macroinvertebrate community composition and in the associated community metrics due to distinct flow conditions between the two seasons. A combination of multivariate analyses (canonical correspondence analysis (CCA)) and biological indicator analysis were used to examine these patterns. Chironomidae was the most abundant family (>60%) in the upper mainstem river and stream sites. Stream sites were positively associated with CCA axis 2, being characterised by high turbidity and lower pH, salinity, phosphate concentration, channel width and canopy cover. Canopy cover, channel width, substrate embeddedness, phosphate concentration, pH, salinity and turbidity all had a significant effect on macroinvertebrate community composition. Using CCA variation partitioning, water quality was, however, a better predictor of benthic macroinvertebrate composition than sediment chemical conditions. Furthermore, our results suggest that seasonality had little effect on structuring benthic macroinvertebrate communities in this south-eastern zone of South Africa, despite clear changes in sediment chemistry. This likely reflects the relative lack of major variability in water chemistry compared to sediment chemistry between seasons and the relatively muted variability in precipitation between seasons than the more classic Austral temperate climates.

Matched MeSH terms: Rivers
Water Quality Modelling for River Activities Management: Example from a Low- and Middle-Income Country

Zahidi I, Wilson G, Brown K, Hou FKK

J Health Pollut, 2020 Dec;10(28):201207.
PMID: 33324504 DOI: 10.5696/2156-9614-10.28.201207

Background: Rivers are susceptible to pollution and water pollution is a growing problem in low- and middle-income countries (LMIC) with rapid development and minimal environmental protections. There are universal pollutant threshold values, but they are not directly linked to river activities such as sand mining and aquaculture. Water quality modelling can support assessments of river pollution and provide information on this important environmental issue.
Objectives: The objective of the present study was to demonstrate water quality modelling methodology in reviewing existing policies for Malaysian river catchments based on an example case study.
Methods: The MIKE 11 software developed by the Danish Hydraulic Institute was used to model the main pollutant point sources within the study area - sand mining and aquaculture. Water quality data were obtained for six river stations from 2000 to 2015. All sand mining and aquaculture locations and approximate production capacities were quantified by ground survey. Modelling of the sand washing effluents was undertaken with the advection-dispersion module due to the nature of the fine sediment. Modelling of the fates of aquaculture deposits required both advection-dispersion and Danish Hydraulic Institute ECO Lab modules to simulate the detailed interactions between water quality determinants.
Results: According to the Malaysian standard, biochemical oxygen command (BOD) and ammonium (NH4) parameters fell under Class IV at most of the river reaches, while the dissolved oxygen (DO) parameter varied between Classes II to IV. Total suspended solids (TSS) fell within Classes IV to V along the mid river reaches of the catchment.
Discussion: Comparison between corresponding constituents and locations showed that the water quality model reproduced the long-term duration exceedance for the main body of the curves. However, the water quality model underestimated the infrequent high concentration observations. A standard effluent disposal was proposed for the development of legislation and regulations by authorities in the district that could be replicated for other similar catchments.
Conclusions: Modelling pollutants enables observation of trends over the years and the percentage of time a certain class is exceeded for each individual pollutant. The catchment did not meet Class II requirements and may not be able to reach Class I without extensive improvements in the quality and reducing the quantity of both point and non-point effluent sources within the catchment.
Competing Interests: The authors declare no competing financial interests.

Matched MeSH terms: Rivers
Vulnerability of Vietnam to typhoons: A spatial assessment based on hazards, exposure and adaptive capacity

Nguyen KA, Liou YA, Terry JP

Sci Total Environ, 2019 Sep 10;682:31-46.
PMID: 31121354 DOI: 10.1016/j.scitotenv.2019.04.069

Typhoons have devastating impacts across many Asian countries. Vietnam is presently one of the most disaster-prone nations. Typhoons regularly disrupt human lives and livelihoods in various ways and cause significant damage. Making efficient policy decisions to minimize the vulnerability of affected communities is crucial. This requires a deep understanding of the factors that make a society vulnerable to extreme events and natural disasters. An appropriate approach is integrating the three dimensions of hazard, exposure and sensitivity, and community adaptive capacity. However, the vulnerability and adaptive capacity response to typhoons within Vietnam is poorly investigated. Here, we develop a conceptual framework that incorporates 21 indicators to identify vulnerability and adaptive capacity (VAC) using geospatial techniques at regional scales, applied over Vietnam. We find large spatial differences in VAC and are able to identify the top-priority regions that need to enhance their adaptation to typhoons. The Southern Coastal area, South East and Red River Delta demonstrate high and very high vulnerability because of their physical features and the intensity of typhoons that frequently cross these parts of Vietnam. The lower Mekong Delta and Northern Coastal areas are vulnerable to typhoon-driven flood threats, in particular where compounded by sea-level rise. Our framework successfully identified the spatial distribution and different levels of VAC within acceptable limits of uncertainty. It can therefore serve as a template to tackle national issues in disaster risk reduction in Vietnam and assist in the development of suitable mitigation strategies to achieve sustainable outcomes.

Matched MeSH terms: Rivers
Verifying the applicability of SWAT to simulate fecal contamination for watershed management of Selangor River, Malaysia

Kondo T, Sakai N, Yazawa T, Shimizu Y

Sci Total Environ, 2021 Jun 20;774:145075.
PMID: 33609845 DOI: 10.1016/j.scitotenv.2021.145075

The Soil and Water Assessment Tool (SWAT) ecohydrological model was utilized to simulate fecal contamination in the 1937 km2 Selangor River Watershed in Malaysia. The watershed conditions posed considerable challenges owing to data scarcity and tropical climate conditions, which are very different from the original conditions that SWAT was developed and tested for. Insufficient data were compensated by publicly available data (e.g., land cover, soil, and weather) to run SWAT. In addition, field monitoring and interviews clarified representative situations of pollution sources and loads, which were used as input for the model. Model parameters determined by empirical analyses in the USA (e.g., surface runoff, evapotranspiration, and temperature adjustment for bacteria die-off) are thoroughly discussed. In particular, due consideration was given to tropical climate characteristics such as intense rainfall, high potential evapotranspiration, and high temperatures throughout the year. As a result, the developed SWAT successfully simulated fecal contamination ranging several orders of magnitude along with its spatial distribution (i.e., Nash-Sutcliffe Efficiency (NSE) = 0.64, Root Mean Square Error-Observations Standard Deviation Ratio (RSR) = 0.64 at six mainstem sites, and NSE = 0.67 and RSR = 0.57 at 12 major tributaries). Moreover, mitigation countermeasures for future worsening of fecal contamination (i.e., E.coli concentration > 20,000 CFU/100 mL for 690 days during nine years at a raw water intake point for Kuala Lumpur [KL] residents) were analyzed through scenario simulations, thereby contributing to discussing effective watershed management. The results propose improving decentralized sewage treatment systems and treating chicken manure with effective microorganisms in order to guarantee water safety for KL residents (i.e., E.coli concentrations <20,000 CFU/100 mL throughout the period, considering Malaysian standards). Accordingly, this study verified the applicability of SWAT to simulate fecal contamination in areas that are difficult to model and suggests solutions for watershed management based on quantitative evidence.

Matched MeSH terms: Rivers*
Fulltext Vegetative swale for treatment of stormwater runoff from construction site

Ismail, A. F., Sapari, N., Abdul Wahab, M. M.

Pertanika Journal of Science & Technology, 2014;22(1):55-64.
MyJurnal

Land development, especially construction works, increase storm water volumes and pollution loads into rivers and lakes. The temporary drainage system at construction sites, particularly during the construction stage discharges a large amount of pollutants that can damage the aquatic system of the receiving water bodies. The potential of vegetative swale to alleviate this problem was evaluated. The size of the constructed vegetative swale was 7cm deep, 400cm long and 15cm wide at the bottom, and 17cm wide at the top. The experiment was conducted batch wise by filling the storage tank with the run-off water from the construction site. The water was allowed to flow through a pipe into the retention basin to maintain uniform flow before it entered the swale. The study showed that the run-off infiltrated through the soil at a rate of 489.6 mm/hr. Samples of surface run-off and infiltration water were collected at the end and the bottom of the swale. The results indicate that chemical oxygen demand (COD), total suspended solid (TSS), turbidity, iron and zinc were reduced by 85.4%, 80.8%, 36.4%, 52.8% and 96.0%, respectively, by surface flow and 91.1%, 98.8%, 58.2% 55.5% and 98.1%, respectively, by infiltration. Removal of nitrate and phosphorus by the planted vegetation was 69.4% and 21.1%, respectively, by infiltration. However, nutrient removal by surface flow was negligible. In conclusion, the vegetative swale was able to improve the water quality of the storm water run-off from the construction site from Class V to Class III, according to the Interim National Water Quality Standards for Malaysia.

Matched MeSH terms: Rivers
Variations in the migratory history of the tropical catadromous eels Anguilla bicolor bicolor and A. bicolor pacifica in south-east Asian waters

Arai T, Chino N

J Fish Biol, 2019 May;94(5):752-758.
PMID: 30847927 DOI: 10.1111/jfb.13952

Fish movements between aquatic habitats of different salinity ranges (fresh, estuarine, marine) by the tropical catadromous eels Anguilla bicolor bicolor and A. bicolor pacifica were examined by analysing the otolith strontium and calcium concentrations of yellow (immature) and silver (mature) stage eels collected in south-east Asian (Indonesia, Malaysia and Vietnam) waters. The ratios suggest that all migratory-type eels, including freshwater, brackish water and marine residents, pass the river mouth. However, the habitat preference was different among the sites (countries). In Indonesia and Vietnam, most A. bicolor bicolor and A. bicolor pacifica were either marine or brackish water residents in this study. Alternatively, most A. bicolor bicolor were freshwater residents in Malaysia; such a typical catadromous migration pattern in these eels has not been found in previous studies. The wide range of otolith Sr:Ca in both subspecies indicates that the habitat use of these tropical eels was opportunistic among fresh, brackish and marine waters during their growth phases following recruitment to coastal areas. The geographical variability of migratory histories suggests that habitat use might be determined by the inter and intraspecific competition and environmental conditions at each site.

Matched MeSH terms: Rivers
Variation partitioning of benthic diatom community matrices: Effects of multiple variables on benthic diatom communities in an Austral temperate river system

Dalu T, Wasserman RJ, Magoro ML, Mwedzi T, Froneman PW, Weyl OLF

Sci Total Environ, 2017 Dec 01;601-602:73-82.
PMID: 28551541 DOI: 10.1016/j.scitotenv.2017.05.162

This study explores diatom community dynamics in a highly modified semi-arid temperate region river system characterised by inconsistent river flow. Various water and sediment environmental variables were assessed using a multi-faceted analysis approach to determine the spatio-temporal drivers of benthic diatom communities in the river system. Overall, the diatom community was generally dominated by pollution tolerant species, reflecting the anthropogenic intensity and activities on the river system. Diatom community composition was found to be largely determined by water column chemistry variables particularly nutrient concentrations in comparison to sediment chemistry and physical variables. Strong seasonal diatom species composition was also observed and this was driven by strong seasonal variations in nutrient loads and metal concentrations, a result of the variable water flow across the two seasons. However, the greater temporal variation in communities was observed in the smaller systems with the mainstream river system being more homogenous over time. In addition, diatom community composition and environmental variables were found to be different and more pronounced between streams and mainstream sites, than between canals and streams. The study highlights the complex interaction between water column, sediment and physical variables in determining the diatom species composition in small river systems. It also highlights the importance of river flow inconsistency as an indirect variable that alters primary drivers such as nutrient concentrations in the water column and heavy metal levels in the sediment.

Matched MeSH terms: Rivers/chemistry*
Valorization of biodiesel side stream waste glycerol for rhamnolipids production by Pseudomonas aeruginosa RS6

Baskaran SM, Zakaria MR, Mukhlis Ahmad Sabri AS, Mohamed MS, Wasoh H, Toshinari M, et al.

Environ Pollut, 2021 Feb 13;276:116742.
PMID: 33621735 DOI: 10.1016/j.envpol.2021.116742

Biodiesel side stream waste glycerol was identified as a cheap carbon source for rhamnolipids (RLs) production which at the same time could improve the management of waste. The present study aimed to produce RLs by using Pseudomonas aeruginosa RS6 utilizing waste glycerol as a substrate and to evaluate their physico-chemicals properties. Fermentation conditions such as temperature, initial medium pH, waste glycerol concentration, nitrogen sources and concentrations resulted in different compositions of the mono- and di-RLs produced. The maximum RLs production of 2.73 g/L was obtained when P. aeruginosa RS6 was grown in a basal salt medium supplemented with 1% waste glycerol and 0.2 M sodium nitrate at 35 °C and pH 6.5. At optimal fermentation conditions, the emulsification index (E24) values of cooking oil, diesel oil, benzene, olive oil, petroleum, and kerosene were all above E24=50%. The surface tension reduction obtained from 72.13 mN/m to 29.4-30.4 mN/m was better than the surface activity of some chemical-based surfactants. The RLs produced possessed antimicrobial activities against Gram-negative and Gram-positive bacteria with values ranging from 37% to 77% of growth inhibition when 1 mg/mL of RLs was used. Concentrations of RLs below 1500 μg/mL did not induce phytotoxicity effects on the tested seeds (Vigna radiata) compared to the chemical-based- surfactant, SDS. Furthermore, RLs tested on zebrafish (Danio rerio) embryos only exhibited low acute toxicity with an LC50 value of 72.97 μg/mL at 48 h of exposure suggesting a green and eco-biochemical worthy of future applications to replace chemical-based surfactants.

Matched MeSH terms: Rivers
Validation of the hypothesis on carrying capacity limits using the water environment carrying capacity

Zhou XY, Zheng B, Khu ST

Sci Total Environ, 2019 May 15;665:774-784.
PMID: 30790750 DOI: 10.1016/j.scitotenv.2019.02.146

The concept of "carrying capacity" has been widely used in various disciplines in reference to human-environment sustainability. No unified cognition exists regarding carrying capacity limits for humans. As a typical type of carrying capacity, the water environment carrying capacity (WECC) has been researched for human-water environment sustainability. However, most recent research has focused on the assessment of the water environment carrying capacity of a certain region or river basin. The detailed resilience potential of human-water environment systems that could improve the local water environment carrying capacity has not been systematically exploited. The key concerns of the existence of water environment carrying capacity limits and the exact value have not been addressed. This study first distinguished the characteristics of related concepts, such as carrying capacity, planetary boundaries, resilience, limitations, thresholds and tipping points. An analytical framework was then established to exploit the resilience potential from the four dimensions of "scale, structure, pattern and network". The economy scale with full use of the resilience potential is 11,511,880 M yuan under the current technology and development status, which is nearly 37 times that of the current scale of the economy. The analytical framework confirms that the limit on the water environment carrying capacity is a dynamic value, which could be changed from the four dimensions. The socioeconomic scale that the local water environment can support would be nearly unlimited in some extreme ideal situation. The results would provide some enlightenment on the carrying capacity and other similar marked concepts of theoretical research and provide support for human-environment sustainability.

Matched MeSH terms: Rivers
Fulltext Using Non-supervised Artificial Neural Network for Determination of Anthropogenic Disturbance in a River System

Rosli NRM, Yahya K

Trop Life Sci Res, 2017 Jul;28(2):189-199.
PMID: 28890770 MyJurnal DOI: 10.21315/tlsr2017.28.2.14

The study of river water quality plays an important role in assessing the pollution status and health of the water bodies. Human-induced activities such as domestic activities, aquaculture, agriculture and industries have detrimentally affected the river water quality. Pinang River is one of the important rivers in Balik Pulau District that supplies freshwater for human consumption. A total of 442 physical and chemical parameters data of the Pinang River, Balik Pulau catchment were analysed to determine the sources of pollutants entering the river. Non-supervised artificial neural network (ANN) was employed to classify and cluster the river into upstream, middle-stream and downstream zones. The monitored data and non-supervised ANN analysis demonstrated that the source of nitrate was derived from the upper part of the Pinang River, Balik Pulau while the sources of nitrite, ammonia and ortho-phosphate are predominant at the middle-stream of the river system. Meanwhile, the sources of high total suspended solid and biological oxygen demand were concentrated at the downstream of the river.

Matched MeSH terms: Rivers
Underwater DVI: Simple fingerprint technique for positive identification

Khoo LS, Hasmi AH, Mahmood MS, Vanezis P

Forensic Sci Int, 2016 Sep;266:e4-e9.
PMID: 27567043 DOI: 10.1016/j.forsciint.2016.08.019

An underwater disaster can be declared when a maritime accident occurred or when an aircraft is plunged into water area, be it ocean, sea or river. Nevertheless, handling of human remains in an underwater recovery operation is often a difficult and demanding task as working conditions may be challenging with poor to no visibility, location of remains at considerable depths and associated hazards from surrounding water. A case of the recent helicopter crash, into a famous river in Sarawak, domiciled by huge crocodiles, is discussed in this paper. Search and recovery team as well as the combat divers from the Special Elite Troop Commando, known as VAT 69, were deployed to the scene to perform the underwater recovery to search for all the victims on board involving five Malaysians with a pilot of Philippines nationality. This paper highlights the limitations and challenges faced during the underwater search and recovery. All the bodies recovered were in moderate decomposition stage with crushed injuries and mutilated face and body. A simple and conventional fingerprint technique were used to record the fingerprint. The prints impressions were later photographed using a smartphone and transferred back to the RMP headquarters in Kuala Lumpur for fingerprint match by using WhatsApp Messenger, a phone application. All the first five victims were identified within an average of 10min. The last victim recovered was the pilot. For foreign nationals, the Immigration Department of Malaysia will record the prints of both index fingers only. The lifting of the fingerprint of the last victim was the most challenging in which only one index finger left that can be used for comparison. A few techniques were attempted using the black printer's ink, glass and tape techniques for the last victim. Subsequently, images of the prints impression were taken using the same smartphone with additional macro lens attached to it to enhance the resolution. The images were transferred to the RMP headquarters through WhatsApp Messenger. The prints were confirmed to be the pilot 20min later.

Matched MeSH terms: Rivers
Understanding Giardia infections among rural communities using the one health approach

Lee SC, Ngui R, Tan TK, Roslan MA, Ithoi I, Mahdy MAK, et al.

Acta Trop, 2017 Dec;176:349-354.
PMID: 28859958 DOI: 10.1016/j.actatropica.2017.08.030

The epidemiology of giardiasis in rural villages in Peninsular Malaysia was examined in the context of the One Health triad that encompasses humans, animals and environment (i.e. river water). A cross-sectional study was carried out among five rural communities in Malaysia to determine the prevalence of Giardia duodenalis in humans, animals and river water. Fecal samples collected from humans and animals were examined by light microscopy. Water was sampled from the rivers adjacent to the target communities and investigated for the occurrence of Giardia cysts. The isolated cysts were further genotyped targeting the glutamate dehydrogenase and triosephosphate isomerase genes. The overall prevalence of G. duodenalis was 6.7% (18/269) and 4.7% (8/169) among humans and animals, respectively. Giardia cysts (mean concentration range: 0.10-5.97 cysts/L) were also found in adjacent rivers at four out of the five villages examined. At Kemensah and Kuala Pangsun, Giardia cysts were isolated from humans [rate: 3.7% each (of 54 each)], animals [rates: 6.3% (of 62) and 11.3% (of 16), respectively] and river water [average concentration of 9 samples each: 0.83±0.81 and 5.97±7.00, respectively]. For both villages at Pos Piah and Paya Lebar, 12.2% (of 98) and 6.1% (of 33) of collected human samples were infected, respectively whilst none of the collected animals samples in these villages were found to be positive. The river water samples of these two villages were also contaminated (average concentration: 0.20±0.35 (of 9) and 0.10±0.19 (of 3), respectively). In conclusion, Giardia cysts were simultaneously observed in the human-animal-environment (i.e., river water) interfaces in at least two of five studied communities highlighting a vital need to improve understanding on the interplay of transmission dynamics, the role of infected humans and animals in contaminating the water sources and the role of water as a vehicle of disease transmission in these communities. Indeed, this study illustrates the One Health approach which is to recognize that the optimal health of humans are interconnected with the well-being of animals and their environment.

Matched MeSH terms: Rivers/parasitology*
Ubiquitous occurrence of sulfonamides in tropical Asian waters

Shimizu A, Takada H, Koike T, Takeshita A, Saha M, Rinawati, et al.

Sci Total Environ, 2013 May 1;452-453:108-15.
PMID: 23500404 DOI: 10.1016/j.scitotenv.2013.02.027

Seven sulfonamides, trimethoprim, five macrolides, lincomycin and three tetracyclines were measured in 150 water samples of sewage, livestock and aquaculture wastewater, and river and coastal waters, in five tropical Asian countries. The sum of the concentrations of the target antibiotics in sewage and heavily sewage-impacted waters were at sub- to low-ppb levels. The most abundant antibiotic was sulfamethoxazole (SMX), followed by lincomycin and sulfathiazole. The average concentration of SMX in sewage or heavily sewage-impacted waters was 1720 ng/L in Vietnam (Hanoi, Ho Chi Minh, Can Tho; n=15), 802ng/L in the Philippines (Manila; n=4), 538 ng/L in India (Kolkata; n=4), 282 ng/L in Indonesia (Jakarta; n=10), and 76 ng/L in Malaysia (Kuala Lumpur; n=6). These concentrations were higher than those in Japan, China, Europe, the US and Canada. A predominance of sulfonamides, especially SMX, is notable in these tropical countries. The higher average concentrations, and the predominance of SMX, can be ascribed to the lower cost of the antibiotics. Both the concentration and composition of antibiotics in livestock and aquaculture wastewater varied widely. In many cases, sulfamethazine (SMT), oxytetracycline (OTC), lincomycin, and SMX were predominant in livestock and aquaculture wastewater. Both human and animal antibiotics were widely distributed in the respective receiving waters (i.e., the Mekong River and Manila Bay). SMT/SMX ratios indicate a significant contribution from livestock wastewater to the Mekong River and nearby canals, with an estimated ~10% of river water SMX derived from such wastewater. Mass flow calculations estimate that 12 tons of SMX is discharged annually from the Mekong River into the South China Sea. Riverine inputs of antibiotics may significantly increase the concentration of such antibiotics in the coastal waters.

Matched MeSH terms: Rivers/chemistry
Two new Tytthoscincus Linkem, Diesmos, Brown (Squamata; Scincidae) from Peninsular Malaysia and another case of microsyntopy between ecologically specialized, unrelated, leaf-litter species

Grismer LL, Wood PLJ, Ahmad AB, Baizul-Hafsyam BS, Afiq-Shuhaimi M, Rizal SA, et al.

Zootaxa, 2018 May 29;4425(1):87-107.
PMID: 30313468 DOI: 10.11646/zootaxa.4425.1.5

Two new species of diminutive, sympatric, lowland, leaf-litter skinks of the genus Tytthoscincus Linkem, Diesmos Brown from the Sekayu region of Hulu Terengganu, Terengganu State in northeastern Peninsular Malaysia are described on the basis genetic and morphological data. One of the new species, T. monticolus sp. nov., was collected in a hilly riparian area along Sungai (=river) Bubu and is most closely related to an undescribed species from the Tembak Reservoir area. The other, T. keciktuek sp. nov. collected along Sungai Peres, is most closely related to T. perhentianensis Grismer, Wood, Grismer from Pulau (=island) Perhentian Besar. Sympatry and syntopy of multiple, specialized, unrelated, leaf-litter species of Tytthoscincus was previously only known from upland areas and these new species represent the first example of lowland of sympatry. More importantly, however, these endemic species add to a growing body of research and discoveries that continue to underscore the unrealized biodiversity of the riparian systems of Hulu Terengganu and the Sekayu region and their need for protection and continued study.

Matched MeSH terms: Rivers

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links