Browsing by Author "Md Firoz Khan"

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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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    An Assessment of Coastal Vulnerability of Pahang's Coast Due to Sea Level Rise
    (Science Publishing Corporation, 2018) Fazly Amri Mohd; Khairul Nizam Abdul Maulud; Othman A. Karim; Rawshan Ara Begum; Md Firoz Khan; Wan Shafrina Wan Mohd Jaafar; Sharifah Mastura Syed Abdullah; Mohd Ekhwan Toriman; Mohd Khairul Amri Kamarudin; Muhammad Barzani Gasim; Noorjima Abd Wahab
    Climate change interacts in a different way with varieties of human activities and other drivers of change along coastlines. Sea level rise (SLR) is one of the major impacts of global warming. Changes in climate extremes and SLR may impact the critical infrastructures such as coastal road, jetty and chalets as well as the local community. The population and assets exposed to coastal risks will increase significantly due to population growth, economic development and urbanization in the future. As most of the cities in Malaysia are situated near the coast, immediate actions are needed to minimize the undesired outcome due to the SLR.The main objective of this study is to identify physical variables that may have impacts on the coastal area, thus develop a coastal vulnerability index (CVI) for the East Coast of Peninsular Malaysia. Seven (7) physical variables have been identified to assess the CVI that consists of geomorphology, coastal slope, shoreline change rate, mean significant wave height, mean tidal range, relative sea level rate and land use.
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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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    Characteristics and health effect of heavy metals on non-exhaust road dusts in Kuala Lumpur
    (Elsevier, 2020) Muhammad Ikram A. Wahab; Wan Mohd Amirfaqry Abd Razak; Mazrura Sahani; Md Firoz Khan
    This study aimed to assess the concentrations and health effect of trace metals [cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)] on the road dust of selected locations in the city of Kuala Lumpur. Sampling was conducted thrice at four locations, namely, Tun Razak Road, Raja Abdullah Road, Tunku Abdul Rahman (TAR) Road, and Ayer Molek Road. The concentrations of trace metals in road dust were analyzed by inductively coupled plasma mass spectrometry.
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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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    Chemical characterization and source apportionment of PM2.5 near semi-urban residential-industrial areas
    (Springer, 2022) Nadhira Dahari; Khalida Muda; Md Firoz Khan; Mohd. Talib Latif; Norelyza Hussein; Doreena Dominick
    This study aims to determine the concentrations of the trace metals (TM) and water soluble inorganic ions (WSII) of the PM2.5 pollutant collected in the suburban industrial-residential airshed during the southwest (SW), inter-monsoon (IM) and northeast (NE) monsoons in Skudai, Johor Bahru. The PM2.5 samples were collected using the MiniVol™ portable air sampler equipped with filter paper. The TM and WSII of PM2.5 were determined by using the inductively coupled plasma-mass spectrometry (ICP-MS) and ion chromatography (IC), respectively. The sources of the PM2.5 composition were determined using the Positive Matrix factorisation (PMF) and the origin of the measured air-masses were determined by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT).
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    Coastal meteorology on the dispersion of air particles at the Bachok GAW Station
    (Elsevier, 2021) Haasyimah Ab. Rahim; Md Firoz Khan; Zul Fadhli Ibrahim; Asadullah Shoaib; Hamidah Suradi; Noraini Mohyeddin; Azizan A. Samah; Sumiani Yusoff
    Meteorology over coastal region is a driving factor to the concentration of air particles and reactive gases. This study aims to conduct a research to determine the level of year-round air particles and the interaction of the meteorological driving factors with the particle number and mass in 2018, which is moderately influenced by Southeast Asian haze. We obtained the measurement data for particle number count (PNC), mass, reactive gases, and meteorological factors from a Global Atmospheric Watch (GAW) station located at Bachok Marine Research Center, Bachok, Kelantan, Malaysia.
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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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    Concentration and source identification of polycyclic aromatic hydrocarbons (PAHs) in PM10 of urban, industrial and semi-urban areas in Malaysia
    (Elsevier, 2014) Anas Ahmad Jamhari; Mazrura Sahani; Mohd Talib Latif; Kok Meng Chan; Hock Seng Tan; Md Firoz Khan; Norhayati Mohd Tahir
    Particulate matter (PM10) associated with polycyclic aromatic hydrocarbons (PAHs) in ambient air were determined at two sites within the Klang Valley, Kuala Lumpur (urban, KL) and Petaling Jaya (industrial, PJ), and one site outside the Klang Valley, Bangi (semi-urban, BG). This study aimed to determine the concentration and distribution of PAHs in PM10 and the source of origin through principal component analysis (PCA) and diagnostic ratio analysis.
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    Distribution of surfactants along the estuarine area of Selangor River, Malaysia
    (Elsevier, 2014) Murad Ali Alsalahi; Mohd Talib Latif; Masni Mohd Ali; Sami Muhsen Magam; Nurul Bahiyah Abd Wahid; Md Firoz Khan; Suhaimi Suratman
    This study aims to determine the levels of methylene blue active substances (MBAS) and ethyl violet active substances (EVAS) as anionic surfactants and of disulphine blue active substances (DBAS) as cationic surfactants in the surface microlayer (SML) around an estuarine area using colorimetric methods.
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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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    Impact of regional haze towards air quality in Malaysia: A review
    (Elsevier, 2018) Mohd Talib Latif; Murnira Othman; Nurfathehah Idris; Liew Juneng; Ahmad Makmom Abdullah; Wan Portia Hamzah; Md Firoz Khan; Nik Meriam Nik Sulaiman; Jegalakshimi Jewaratnam; Nasrin Aghamohammadi; Mazrura Sahani; Chung Jing Xiang; Fatimah Ahamad; Norhaniza Amil; Mashitah Darus; Helena Varkkey; Fredolin Tangang; Abu Bakar Jaafar
    Haze is a common phenomenon afflicting Southeast Asia (SEA), including Malaysia, and has occurred almost every year within the last few decades. Haze is associated with high level of air pollutants; it reduces visibility and affects human health in the affected SEA countries. This manuscript aims to review the potential origin, chemical compositions, impacts and mitigation strategies of haze in Malaysia.
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    Indoor generated PM2.5 compositions and volatile organic compounds: Potential sources and health risk implications
    (Elsevier, 2020) Siti Amira ‘Ainaa’ Idris; Marlia M. Hanafiah; Md Firoz Khan; Haris Hafizal Abd Hamid
    The aim of the present study was to investigate the potential sources of heavy metals in fine air particles (PM2.5) and benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) in gas phase indoor air. PM2.5 samples were collected using a low volume sampler. BTEX samples were collected using passive sampling onto sorbent tubes and analyzed using gas chromatography-mass spectrometry (GC-MS).
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    Interaction of PM10 concentrations with local and synoptic meteorological conditions at different temporal scales
    (Elsevier, 2020) Hanashriah Hassan; Mohd Talib Latif; Liew Juneng; Norhaniza Amil; Md Firoz Khan; Diong Jeong Yik; Nur Aleesha Abdullah
    Changing meteorological conditions over short and long time scales are anticipated to affect the concentrations of particulate matter with aerodynamic diameter below than 10 μm (PM10) in the atmosphere. This study aims to identify the temporal characteristics of PM10 including its relationship with local and synoptic meteorological conditions in Petaling Jaya (PJ), Malaysia from 1996 to 2016.A high volume sampler (HVS), mounted on the rooftop of MetMalaysia, was used to monitor daily PM10 concentrations. The meteorological parameter data were obtained from the MetMalaysia PJ station.
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    Local and transboundary factors' impacts on trace gases and aerosol during haze episode in 2015 El Niño in Malaysia
    (Elsevier, 2018) Nur Adilla Che Samsuddin; Md Firoz Khan; Khairul Nizam Abdul Maulud; Ahmad Hazuwan Hamid; Fahia Tarannum Munna; Muhammad Aizat Ab Rahim; Mohd Talib Latif; Md. Akhtaruzzaman
    Southeast Asian haze is a semi-natural phenomenon that chokes the region each year during the dry monsoon season. Smoke-haze episodes caused by the vegetation and peat fires in Indonesia severely affected large parts of Malaysia during the 2015 El Niño phenomenon. This study aimed to evaluate the factors that influenced the concentrations of aerosol and trace gases during the 2015 haze and non-haze period on a semi-urban site in the southern part of Malaysian peninsula that facing Sumatra (Muar, Site A), and on an urban site near to Kuala Lumpur, influenced by the city centre (Cheras, Site B).
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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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    Monsoonal variations in atmospheric surfactants at different coastal areas of the Malaysian Peninsula
    (Elsevier, 2016) Shoffian Amin Jaafar; Mohd Talib Latif; Intan Suraya Razak; Muhammad Zulhilmi Shaharudin; Md Firoz Khan; Nurul Bahiyah Abd Wahid; Suhaimi Suratman
    This study determined the effect of monsoonal changes on the composition of atmospheric surfactants in coastal areas. The composition of anions (SO42 −, NO3−, Cl−, F−) and the major elements (Ca, K, Mg, Na) in aerosols were used to determine the possible sources of surfactants. Surfactant compositions were determined using a colori-metric method as methylene blue active substances (MBAS) and disulphine blue active substances (DBAS). The anion and major element compositions of the aerosol samples were determined by ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS), respectively.
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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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    Risk of concentrations of major air pollutants on the prevalence of cardiovascular and respiratory diseases in urbanized area of Kuala Lumpur, Malaysia
    (Elsevier, 2019) Muhammad Abdul Basit Ahmad Tajudin; Md Firoz Khan; Wan Rozita Wan Mahiyuddin; Rozita Hodd; Mohd Talib Latif; Ahmad Hazuwan Hamid; Sufian Abd Rahman; Mazrura Sahania
    Rapid urbanisation in Malaysian cities poses risks to the health of residents. This study aims to estimate the relative risk (RR) of major air pollutants on cardiovascular and respiratory hospitalisations in Kuala Lumpur. Daily hospitalisations due to cardiovascular and respiratory diseases from 2010 to 2014 were obtained from the Hospital Canselor Tuanku Muhriz (HCTM). The trace gases, PM10 and weather variables were obtained from the Department of Environment (DOE) Malaysia in consistent with the hospitalisation data. The RR was estimated using a Generalised Additive Model (GAM) based on Poisson regression. A "lag" concept was used where the analysis was segregated into risks of immediate exposure (lag 0) until exposure after 5 days.