Browsing by Author "Mohd Shahrul Mohd Nadzir"

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    Airborne particles in the city center of Kuala Lumpur: Origin, potential driving factors, and deposition flux in human respiratory airways
    (Elsevier, 2019) Md Firoz Khan; Ahmad Hazuwan Hamid; Md Aynul Bari; Abdul Basit Ahmad Tajudin; Mohd Talib Latif; Mohd Shahrul Mohd Nadzir; Mazrura Sahani; Muhammad Ikram A. Wahab; Yusri Yusup; Khairul Nizam Abdul Maulud; Mohd Famey Yusoff; Nowshad Amin; Md Akhtaruzzaman; Warren Kindzierski; Prashant Kumar
    Equatorial warming conditions in urban areas can influence the particle number concentrations (PNCs), but studies assessing such factors are limited. The aim of this study was to evaluate the level of size-resolved PNCs, their potential deposition rate in the human respiratory system, and probable local and transboundary inputs of PNCs in Kuala Lumpur.
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    Ambient BTEX levels over urban, suburban and rural areas in Malaysia
    (Springer, 2019) Haris Hafizal Abd Hamid; Mohd Talib Latif; Mohd Shahrul Mohd Nadzir; Royston Uning; Md Firoz Khan; Narayanan Kannan
    Benzene, toluene, ethylbenzene and xylene isomers (BTEX) are volatile organic air pollutants of concern which arise from natural and anthropogenic sources. This study aims to determine and evaluate the BTEX levels in ambient air in selected areas of Malaysia, namely: Kuala Lumpur (KL-urban), Penang (PG-urban), Bangi (BG-suburban), Langkawi (LGK-suburban) and the Danum Valley (DV-rural). Active sampling with sorbent tubes was applied in this study and samples were analysed using thermal desorption (TD) coupled with gas chromatography-mass spectrometry (GC-MS).
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    BTEX compositions and its potential health impacts in Malaysia
    (Elsevier, 2019) Mohd Talib Latif; Fatimah Ahamad; Md Firoz Khan; Mohd Shahrul Mohd Nadzir; Murnira Othman; Mazrura Sahani; Muhammad Ikram Abdul Wahab; Noorlin Mohamad; Royston Uning; Seng Chee Poh; Muhammad Fais Fadzil; Justin Sentian; Norhayati Md Tahir; Haris Hafizal Abd Hamid
    This study aims to determine the composition of BTEX (benzene, toluene, ethylbenzene and xylene) and assess the risk to health at different sites in Malaysia. Continuous monitoring of BTEX in Kuala Lumpur City Centre, Kuala Terengganu, Kota Kinabalu and Fraser Hill were conducted using Online Gas Chromatograph.
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    Concentration and source apportionment of volatile organic compounds (VOCs) in the ambient air of Kuala Lumpur, Malaysia
    (Springer, 2017) Puteri Nurafidah Hosaini; Md Firoz Khan; Nur Ili Hamizah Mustaffa; Norhaniza Amil; Noorlin Mohamad; Shoffian Amin Jaafar; Mohd Shahrul Mohd Nadzir; Mohd Talib Latif
    The accumulation of volatile organic compounds (VOCs) in ambient air affects air quality through the generation of surface level ozone and secondary organic aerosol. A study of the distribution and source apportionment of VOCs was conducted at two stations to investigate the air quality status of Kuala Lumpur. Samples of ambient air were collected into Tedlar sampling bags using an air sampling pump and then pre-concentrated with solid-phase micro-extraction fibre. Gas chromatography-mass spectrometry (GC-MS) was employed to measure the VOC species.
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    Distance impacts toxic metals pollution in mining affected river sediments
    (Elsevier, 2022) Chin Yik Lin; Bibi Noorarlijannah Mohammad Ali; Rohana Tair; Baba Musta; Mohd Harun Abdullah; Fera Cleophas; Feona Isidore; Mohd Shahrul Mohd Nadzir; Muhammad Hatta Roselee; Ismail Yusoff
    The study of metals mobility derived from mining activities in an ultramafic lithology is limited. This study investigates the effects of distance on potentially toxic metals such as Co, Cu, Fe, Mn, Ni, Pb, and Zn pollution, and the geochemical processes of fluvial system downstream of an ex-copper mine (Mamut River). The toxicity level of the river was evaluated using various sediment quality guidelines, ecotoxicological risks (ecological risk and risk index) and pollution indices. The geochemical behavior and stability of these toxic metals in the solid-phase samples were also examined.
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    El Niño driven haze over the Southern Malaysian Peninsula and Borneo
    (Elsevier, 2020) Md Firoz Khan; Ahmad Hazuwan Hamid; Haasyimah Ab Rahim; Khairul Nizam Abdul Maulud; Mohd Talib Latif; Mohd Shahrul Mohd Nadzir; Mazrura Sahani; Kai Qin; Prashant Kumar; Helena Varkkey; Mohammad Rashed Iqbal Faruque; Ng Chee Guan; Seyedeh Parisa Ahmadi; Sumiani Yusoff
    The Southeast Asian (SEA) region is no stranger to forest fires - the region has been suffering from severe air pollution (known locally as "haze") as a result of these fires, for decades. The fires in SEA region are caused by a combination of natural (the El Niño weather pattern) and manmade (slash-and-burn and land clearing for plantations) factors. These fires cause the emissions of toxic aerosols and pollutants that can affect millions of people in the region. Thus, this study aims to identify the impact of the SEA haze on the Southern region of the Malaysian Peninsula and Borneo region of East Malaysia using the entire air quality observation data at surface level in 2015.
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    Long term assessment of air quality from a background station on the Malaysian Peninsula
    (Elsevier, 2014) Mohd Talib Latif; Doreena Dominick; Fatimah Ahamad; Md Firoz Khan; Liew Juneng; Firdaus Mohamad Hamzah; Mohd Shahrul Mohd Nadzir
    Rural background stations provide insight into seasonal variations in pollutant concentrations and allow for comparisons to be made with stations closer to anthropogenic emissions. In Malaysia, the designated background station is located in Jerantut, Pahang. A fifteen-year data set focusing on ten major air pollutants and four meteorological variables from this station were analysed. Diurnal, monthly and yearly pollutant concentrations were derived from hourly continuous monitoring data. Statistical methods employed included principal component regression (PCR) and sensitivity analysis.
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    Observations of BTEX in the ambient air of Kuala Lumpur by passive sampling
    (Elsevier, 2020) Haris Hafizal Abd Hamid; Mohd Talib Latif; Royston Uning; Mohd Shahrul Mohd Nadzir; Md Firoz Khan; Goh Choo Ta; Narayanan Kannan
    Benzene, toluene, ethylbenzene and xylenes (BTEX) are well known hazardous volatile organic compounds (VOCs) due to their human health risks and photochemical effects. The main objective of this study was to estimate BTEX levels and evaluate interspecies ratios and ozone formation potentials (OFP) in the ambient air of urban Kuala Lumpur (KL) based on a passive sampling method with a Tenax® GR adsorbent tube. Analysis of BTEX was performed using a thermal desorption (TD)-gas chromatography mass spectrometer (GCMS). OFP was calculated based on the Maximum Incremental Reactivity (MIR).
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    Prediction of Multivariate Air Quality Time Series Data using Long Short-Term Memory Network
    (Penerbit UTM Press, 2022) Mohd Aftar Abu Bakara; Noratiqah Mohd Ariff; Mohd Shahrul Mohd Nadzir; Ong Li Wen; Fatin Nur Afiqah Suris
    In this study, the air quality model based on the Long Short-Term Memory Network (LSTM) and Auto-Regressive Integrated Moving Average (ARIMA) was developed. The prediction of the particulate matter 10 micrometers or less in diameter (PM10) in Malaysia could be made from both models, and their performance was compared. The purpose of comparison between the two models was to determine the most suitable model to use in predicting PM10 since it is the dominant pollutant in Malaysia most of the time, especially during the haze period. This study used air quality data obtained from the Department of Environment Malaysia from July 2017 to June 2019.
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    Seasonal and long term variations of surface ozone concentrations in Malaysian Borneo
    (Elsevier, 2016) Mohd Talib Latif; Doreena Dominick; Fatimah Ahamad; Nur Shuhada Ahamad; Md Firoz Khan; Liew Juneng; Chung Jing Xiang; Mohd Shahrul Mohd Nadzir; Andrew D. Robinson; Marzuki Ismail; Mohammed Iqbal Mead; Neil R.P. Harris
    Malaysian Borneo has a lower population density and is an area known for its lush rainforests. However, changes in pollutant profiles are expected due to increasing urbanisation and commercial-industrial activities. This study aims to determine the variation of surface O3 concentration recorded at seven selected stations in Malaysian Borneo. Hourly surface O3 data covering the period 2002 to 2013, obtained from the Malaysian Department of Environment (DOE), were analysed using statistical methods.
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    Spatial distribution of fine and coarse particulate matter during a southwest monsoon in Peninsular Malaysia
    (Elsevier, 2021) Munira Othman; Mohd Talib Latif; Anas Ahmad Jamhari; Haris Hafizal Abd Hamid; Royston Uning; Md Firoz Khan; Mohd Shahrul Mohd Nadzir; Mazrura Sahani; Muhammad Ikram Abdul Wahab; Kok Meng Chan
    This study aimed to determine the spatial distribution of PM2.5 and PM10 collected in four regions (North, Central, South and East Coast) of Peninsular Malaysia during the southwest monsoon. Concurrent measurements of PM2.5 and PM10 were performed using a high volume sampler (HVS) for 24 h (August to September 2018) collecting a total of 104 samples. All samples were then analysed for water soluble inorganic ions (WSII) using ion chromatography, trace metals using inductively coupled plasma-mass spectroscopy (ICP-MS) and polycyclic aromatic hydrocarbon (PAHs) using gas chromatography-mass spectroscopy (GC-MS).
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    Wavelet-based time series model to improve the forecast accuracy of PM10 concentrations in Peninsular Malaysia
    (Elsevier, 2015) Doreena Dominick; Mohd Talib Latif; Liew Juneng; Md Firoz Khan; Norhaniza Amil; Mohammed Iqbal Mead; Mohd Shahrul Mohd Nadzir; Phang Siew Moi; Azizan Abu Samah; Matthew J. Ashfold; William T. Sturges; Neil R.P. Harris; Andrew D. Robinson; John A. Pyle
    Particle mass concentrations (PM10, PM2.5 and PM1) and particle number concentration ((PNC); 0.27 μm ≤ Dp ≤ 34.00 μm) were measured in the tropical coastal environment of Bachok, Kelantan on the Malaysian Peninsula bordering the southern edge of the South China Sea. Statistical methods were applied on a three-month hourly data set (9th January to 24th March 2014) to study the influence of north-easterly winds on the patterns of particle mass and PNC size distributions.