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Occurrence of free-living amoebae (Acanthamoeba, Balamuthia, Naegleria) in water samples in Peninsular Malaysia

Gabriel S, Khan NA, Siddiqui R

J Water Health, 2019 Feb;17(1):160-171.
PMID: 30758312 DOI: 10.2166/wh.2018.164

The aim of this study was to determine the occurrence of free-living amoebae (FLA) in Peninsular Malaysia and to compare different methodologies to detect them from water samples. Water samples were collected from tap water, recreational places, water dispensers, filtered water, etc. and tested for FLA using both cultivation and polymerase chain reaction (PCR) via plating assays and centrifugation methods. Amoebae DNA was extracted using Instagene matrix and PCR was performed using genus-specific primers. Of 250 samples, 142 (56.8%) samples were positive for presence of amoebae, while 108 (43.2%) were negative. Recreational water showed higher prevalence of amoebae than tap water. PCR for the plating assays revealed the presence of Acanthamoeba in 91 (64%) samples and Naegleria in 99 (70%) of samples analysed. All samples tested were negative for B. mandrillaris. In contrast, the centrifugation method was less effective in detecting amoebae as only one sample revealed the presence of Acanthamoeba and 52 (29%) samples were positive for Naegleria. PCR assays were specific and sensitive, detecting as few as 10 cells. These findings show the vast distribution and presence of FLA in all 11 states of Peninsular Malaysia. Further studies could determine the possible presence of pathogenic species and strains of free-living amoebae in public water supplies in Malaysia.

Matched MeSH terms: Water Supply/statistics & numerical data*
Assessing the suitability of stream water for five different uses and its aquatic environment

Fulazzaky MA

Environ Monit Assess, 2013 Jan;185(1):523-35.
PMID: 22373956 DOI: 10.1007/s10661-012-2572-6

Surface water is one of the essential resources for supporting sustainable development. The suitability of such water for a given use depends both on the available quantity and tolerable quality. Temporary status for a surface water quality has been identified extensively. Still the suitability of the water for different purposes needs to be verified. This study proposes a water quality evaluation system to assess the aptitude of the Selangor River water for aquatic biota, drinking water production, leisure and aquatic sport, irrigation use, livestock watering, and aquaculture use. Aptitude of the water has been classified in many parts of the river segment as unsuitable for aquatic biota, drinking water production, leisure and aquatic sport as well as aquaculture use. The water quality aptitude classes of the stream water for nine locations along the river are evaluated to contribute to decision support system. The suitability of the water for five different uses and its aquatic ecosystem are verified.

Matched MeSH terms: Water Supply/statistics & numerical data*
Time-lapse resistivity investigation of salinity changes at an ex-promontory land: a case study of Carey Island, Selangor, Malaysia

Tajul Baharuddin MF, Taib S, Hashim R, Zainal Abidin MH, Ishak MF

Environ Monit Assess, 2011 Sep;180(1-4):345-69.
PMID: 21136290 DOI: 10.1007/s10661-010-1792-x

Time-lapse resistivity measurements and groundwater geochemistry were used to study salinity effect on groundwater aquifer at the ex-promontory-land of Carey Island in Malaysia. Resistivity was measured by ABEM Terrameter SAS4000 and ES10-64 electrode selector. Relationship between earth resistivity and total dissolved solids (TDS) was derived, and with resistivity images, used to identify water types: fresh (ρ ( e ) > 6.5 Ω m), brackish (3 Ω m < ρ ( e ) < 6.5 Ω m), or saline (ρ ( e ) < 3 Ω m). Long-term monitoring of the studied area's groundwater quality via measurements of its time-lapse resistivity showed salinity changes in the island's groundwater aquifers not conforming to seawater-freshwater hydraulic gradient. In some aquifers far from the coast, saline water was dominant, while in some others, freshwater 30 m thick showed groundwater potential. Land transformation is believed to have changed the island's hydrogeology, which receives saltwater pressure all the time, limiting freshwater recharge to the groundwater system. The time-lapse resistivity measurements showed active salinity changes at resistivity-image bottom moving up the image for two seasons' (wet and dry) conditions. The salinity changes are believed to have been caused by incremental tide passing through highly porous material in the active-salinity-change area. The study's results were used to plan a strategy for sustainable groundwater exploration of the island.

Matched MeSH terms: Water Supply/statistics & numerical data
Prevalence of Cryptosporidium and Giardia in the water resources of the Kuang River catchment, Northern Thailand

Chuah CJ, Mukhaidin N, Choy SH, Smith GJD, Mendenhall IH, Lim YAL, et al.

Sci Total Environ, 2016 08 15;562:701-713.
PMID: 27110981 DOI: 10.1016/j.scitotenv.2016.03.247

A catchment-scale investigation of the prevalence of Cryptosporidium and Giardia in the Kuang River Basin was carried out during the dry and rainy seasons. Water samples were collected from the Kuang River and its tributaries as well as a major irrigation canal at the study site. We also investigated the prevalence of gastrointestinal parasitic infection among dairy and beef cattle hosts. Cryptosporidium and/or Giardia were detected in all the rivers considered for this study, reflecting their ubiquity within the Kuang River Basin. The high prevalence of Cryptosporidium/Giardia in the upper Kuang River and Lai River is of a particular concern as both drain into the Mae Kuang Reservoir, a vital source of drinking-water to many local towns and villages at the research area. We did not, however, detected neither Cryptosporidium nor Giardia were in the irrigation canal. The frequency of Cryptosporidium/Giardia detection nearly doubled during the rainy season compared to the dry season, highlighting the importance of water as an agent of transport. In addition to the overland transport of these protozoa from their land sources (e.g. cattle manure, cess pits), Cryptosporidium/Giardia may also be re-suspended from the streambeds (a potentially important repository) into the water column of rivers during storm events. Faecal samples from dairy and beef cattle showed high infection rates from various intestinal parasites - 97% and 94%, respectively. However, Cryptosporidium and Giardia were only detected in beef cattle. The difference in management style between beef (freeranging) and dairy cattle (confined) may account for this disparity. Finally, phylogenetic analyses revealed that the Cryptosporidium/Giardia-positive samples contained C. ryanae (non-zoonotic) as well as Giardia intestinalis assemblages B (zoonotic) and E (non-zoonotic). With only basic water treatment facilities afforded to them, the communities of the rural area relying on these water supplies are highly at risk to Cryptosporidium/Giardia infections.

Matched MeSH terms: Water Supply/statistics & numerical data*
Assessment of groundwater salinity and quality in Gaza coastal aquifer, Gaza Strip, Palestine: An integrated statistical, geostatistical and hydrogeochemical approaches study

Abu-Alnaeem MF, Yusoff I, Ng TF, Alias Y, Raksmey M

Sci Total Environ, 2018 Feb 15;615:972-989.
PMID: 29751448 DOI: 10.1016/j.scitotenv.2017.09.320

A comprehensive study was conducted to identify the salinization origins and the major hydrogeochemical processes controlling the salinization and deterioration of the Gaza coastal aquifer system through a combination approaches of statistical and geostatistical techniques, and detailed hydrogeochemical assessments. These analyses were applied on ten physicochemical variables for 219 wells using STATA/SE12 and Surfer softwares. Geostatistical analysis of the groundwater salinity showed that seawater intrusion along the coastline, and saltwater up-coning inland highly influenced the groundwater salinity of the study area. The hierarchical cluster analysis (HCA) technique yielded seven distinct hydrogeochemical signature clusters; (C1&C2: Eocene brackish water invasion, C3 saltwater up-coning, C4 human inputs, C5 seawater intrusion, C6 & C7 rainfall and mixing inputs). Box plot shows a wide variation of most of the ions while Chadha's plot elucidates the predominance of Na-Cl (71.6%) and Ca/Mg-Cl (25%) water types. It is found that, the highest and the lowest levels of salinization and the highest level of nitrate pollution were recorded in the northern area. This result reflects the sensitivity of this area to the human activities and/or natural actions. Around 90.4% of the wells are nitrate polluted. The main source of nitrate pollution is the sewage inputs while the farming inputs are very limited and restricted mostly in the sensitive northern area. Among the hydrogeochemical processes, ion exchange process was the most effective process all over the study area. Carbonate dissolution was common in the study area with the highest level in clusters 6, 7, 4 and 2 in the north while Gypsum dissolution was significant only in cluster 1 in the south and limited in the other clusters. This integrated multi-techniques research should be of benefit for effective utilization and management of the Gaza coastal aquifer system as well as for future work in other similar aquifers systems.

Matched MeSH terms: Water Supply/statistics & numerical data*
The impact of a reduction in fluoride concentration in the Malaysian water supply on the prevalence of fluorosis and dental caries

Mohd Nor NA, Chadwick BL, Farnell DJJ, Chestnutt IG

Community Dent Oral Epidemiol, 2018 10;46(5):492-499.
PMID: 30019792 DOI: 10.1111/cdoe.12407

OBJECTIVE: To assess the prevalence and severity of dental fluorosis and caries among Malaysian children following the reduction in fluoride concentration from 0.7 to 0.5 parts per million (ppm) in the public water supply.
METHODS: This study involved lifelong residents aged 9- and 12-year-olds in fluoridated and nonfluoridated areas in Malaysia (n = 1155). In the fluoridated area, children aged 12 years and 9 years were exposed to 0.7 and 0.5 ppm, respectively, at the times when maxillary central incisors developed. Standardized photographs of maxillary central incisors were blind scored for fluorosis using Dean's criteria. Dental caries was examined using ICDAS-II criteria.
RESULTS: The prevalence of fluorosis (Dean's score ≥ 2) among children in the fluoridated area (35.7%, 95% CI: 31.9%-39.6%) was significantly higher (P

Matched MeSH terms: Water Supply/statistics & numerical data
Determination of radioactive elements and heavy metals in sediments and soil from domestic water sources in northern peninsular Malaysia

Muhammad BG, Jaafar MS, Abdul Rahman A, Ingawa FA

Environ Monit Assess, 2012 Aug;184(8):5043-9.
PMID: 21901308 DOI: 10.1007/s10661-011-2320-3

Soil serves as a major reservoir for contaminants as it posseses an ability to bind various chemicals together. To safeguard the members of the public from an unwanted exposure, studies were conducted on the sediments and soil from water bodies that form the major sources of domestic water supply in northern peninsular Malaysia for their trace element concentration levels. Neutron Activation Analysis, using Nigeria Research Reactor-1 (NIRR-1) located at the Centre for Energy Research and Training, Zaria, Nigeria was employed as the analytical tool. The elements identified in major quantities include Na, K, and Fe while As, Br, Cr, U, Th, Eu, Cs, Co, La, Sm, Yb, Sc, Zn, Rb, Ba, Lu, Hf, Ta, and Sb were also identified in trace quantities. Gamma spectroscopy was also employed to analyze some soil samples from the same area. The results indicated safe levels in terms of the radium equivalent activity, external hazard index as well as the mean external exposure dose rates from the soil. The overall screening of the domestic water sources with relatively high heavy metals concentration values in sediments and high activity concentration values in soil is strongly recommended as their accumulation overtime as a consequence of leaching into the water may be of health concern to the members of the public.

Matched MeSH terms: Water Supply/statistics & numerical data
Fulltext Physicochemical properties associated with the presence of Burkholderia pseudomallei in small ruminant farm water supplies in Peninsular Malaysia

Musa HI, Hassan L, Shamsuddin ZH, Panchadcharam C, Zakaria Z, Aziz SA

Environ Monit Assess, 2018 Mar 22;190(4):241.
PMID: 29569066 DOI: 10.1007/s10661-018-6613-7

Burkholderia pseudomallei causes melioidosis, a life-threatening infection in both humans and animals. Water is an important reservoir of the bacteria and may serve as a source of environmental contamination leading to infection. B. pseudomallei has an unusual ability to survive in water for a long period. This paper investigates physicochemical properties of water associated with the presence of B. pseudomallei in water supply in small ruminant farms in Peninsular Malaysia. Physicochemical properties of water samples taken from small ruminant farms that included temperature, pH, dissolved oxygen (DO2), optical density (OD), and chemical oxygen demand (COD) were measured after which the samples were cultured for B. pseudomallei. Multivariable logistic regression model revealed that slightly acidic water pH and higher COD level were significantly associated with the likelihood of the B. pseudomallei presence in the water.

Matched MeSH terms: Water Supply/statistics & numerical data*
Fulltext Risk assessment of exposure to lead in tap water among residents of Seri Kembangan, Selangor state, Malaysia

Lim CS, Shaharuddin MS, Sam WY

Glob J Health Sci, 2013 Mar;5(2):1-12.
PMID: 23445691 DOI: 10.5539/gjhs.v5n2p1

A cross sectional study was conducted to estimate risk of exposure to lead via tap water ingestion pathway for the population of Seri Kembangan (SK).

Matched MeSH terms: Water Supply/statistics & numerical data