Browsing by Author "Mustafa Ali Mohd"

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    Characterization and source profiling of volatile organic compounds in indoor air of private residences in Selangor State, Malaysia
    (Elsevier, 2017) Nobumitsu Sakai; Shuta Yamamoto; Yasuto Matsui; Md Firoz Khan; Mohd Talib Latif; Mustafa Ali Mohd; Minoru Yoneda
    Volatile Organic Compounds (VOCs) in indoor air were investigated at 39 private residences in Selangor State, Malaysia to characterize the indoor air quality and to identify pollution sources. Twenty-two VOCs including isomers (14 aldehydes, 5 aromatic hydrocarbons, acetone, trichloroethylene and tetrachloroethylene) were collected by 2 passive samplers for 24 h and quantitated using high performance liquid chromatography and gas chromatography mass spectrometry. Source profiling based on benzene/toluene ratio as well as statistical analysis (cluster analysis, bivariate correlation analysis and principal component analysis) was performed to identify pollution sources of the detected VOCs.
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    Occurrence, fate and environmental risk of linear alkylbenzene sulfonate in the Langat and Selangor River basins, Malaysia
    (Elsevier, 2017) Nobumitsu Sakai; Junichi Shirasaka; Yasuto Matsui; Mohd Redzuan Ramli; Kousuke Yoshida; Mustafa Ali Mohd; Minoru Yoneda
    Five homologs (C10-C14) of linear alkylbenzene sulfonate (LAS) were quantitated in surface water collected in the Langat and Selangor River basins using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A geographic information system (GIS) was used to spatially analyze the occurrence of LAS in both river basins, and the LAS contamination associated with the population was elucidated by spatial analysis at a sub-basin level. The LAS concentrations in the dissolved phase (<0.45 μm) and 4 fractions separated by particle size (<0.1 μm, 0.1e1 μm, 1e11 μm and >11 μm) were analyzed to elucidate the environmental fate of LAS in the study area. The environmental risks of the observed LAS concentration were assessed based on predicted no effect concentration (PNEC) normalized by a quantitative structure-activity relationship model.
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    Source profiling of arsenic and heavy metals in the Selangor River basin and their maternal and cord blood levels in Selangor State, Malaysia
    (Elsevier, 2017) Nobumitsu Sakai; Zohour Alsaad; Nguyen Thi Thuong; Kenji Shiota; Minoru Yoneda; Mustafa Ali Mohd
    Arsenic and 5 heavy metals (nickel, copper, zinc, cadmium and lead) were quantitated in surface water (n = 18) and soil/ore samples (n = 45) collected from 5 land uses (oil palm converted from forest, oil palm in peat swamp, bare land, quarry and forest) in the Selangor River basin by inductively coupled plasma mass spectrometry (ICP-MS). Geographic information system (GIS) was used as a spatial analytical tool to classify 4 land uses (forest, agriculture/peat, urban and bare land) from a satellite image taken by Landsat 8. Source profiling of the 6 elements was conducted to identify their occurrence, their distribution and the pollution source associated with the land use. The concentrations of arsenic, cadmium and lead were also analyzed in maternal blood (n = 99) and cord blood (n = 87) specimens from 136 pregnant women collected at the University of Malaya Medical Center for elucidating maternal exposure as well as maternal-to-fetal transfer.
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    Spatial analysis and source profiling of beta-agonists and sulfonamides in Langat River basin, Malaysia
    (Elsevier, 2016) Nobumitsu Sakai; Roslan Mohd Yusof; Marni Sapar; Minoru Yoneda; Mustafa Ali Mohd
    Beta-agonists and sulfonamides are widely used for treating both humans and livestock for bronchial and cardiac problems, infectious disease and even as growth promoters. There are concerns about their potential environmental impacts, such as producing drug resistance in bacteria. This study focused on their spatial distribution in surface water and the identification of pollution sources in the Langat River basin, which is one of the most urbanized watersheds in Malaysia.