Quality
Permanent URI for this collection
Browse
Recent Submissions
Item Embargo Bayesian autoregressive spatiotemporal model of PM10 concentrations across Peninsular Malaysia(Springer, 2018) Edna Manga; Norhashidah AwangRapid industrialization and haze episodes in Malaysia ensure pollution remains a public health challenge. Atmospheric pollutants such as PM10 are typically variable in space and time. The increased vigilance of policy makers in monitoring pollutant levels has led to vast amounts of spatiotemporal data available for modelling and inference. The aim of this study is to model and predict the spatiotemporal daily PM10 levels across Peninsular Malaysia. A hierarchical autoregressive spatiotemporal model is applied to daily PM10 concentration levels from thirty-four monitoring stations in Peninsular Malaysia during January to December 2011.Item Embargo Compositional time series analysis for Air Pollution Index data(Springer, 2018) Nasr Ahmed AL-Dhurafi; Nurulkamal Masseran; Zamira Hasanah ZamzuriThe increasing importance of understanding the structure of Air Pollution Index (API) makes it necessary to come out with a compositional of API based on its pollutants. This will be more comprehensible for the public and easier to cooperate with authorities in reducing the causes of air pollution. Since five pollutants contribute in determining the API values, API can be shown as a compositional data. This study is conducted based on the data of API and its pollutants collected from Klang city in Malaysia for the period of January 2005 to December 2014. The proportion of each pollutant in API is considered as a component with five components in a compositional API. The existence of zero components in some pollutants, that have no effect on API, is a serious problem that prevents the application of log-ratio transformation. Thus, the approach of amalgamation has been used to combine the components with zero in order to reduce the number of zeros. Also, a multiplicative replacement has been utilized to eliminate the zero components and replace them with a small value that maintains the ratios of nonzero components. Transforming the compositional data to log-ratio coordinates has been done using the additive log ratio transformation, and the transformed series is then modeled by using a VAR model.Item Embargo Examining the asymmetric effects of stock markets on Malaysia's air pollution: a nonlinear ARDL approach(Springer, 2019) Usama Al-mulali; Sakiru Adebola Solarin; Ilhan OzturkThe objective of this research is to examine the effects of stock market on air pollution in Malaysia during the period 1980-2017.To realize this aim, a nonlinear autoregressive distributed lag (ARDL) model is constructed. The short results in general revealed that the increase in stock markets will increase CO2 emissions and its significance increases in the long run. Moreover, the decline in stock market will reduce Malaysia's CO2 emissions but only in in the long run.Item Embargo Modeling the stochastic dependence of air pollution index data(Springer, 2018) Yousif Alyousifi; Nurulkamal Masseran; Kamarulzaman IbrahimThe air pollution index (API) is a common tool, which is often used for determining the quality of air in the environment. In this study, a discrete-time Markov chain model is applied for describing the stochastic behaviour of API data. The study reported in this paper is conducted based on the data collected from Klang city in Malaysia for a period of 3 years (2012-2014)Item Embargo Characterization and risk analysis of metals associated with urban ust in Rawang (Malaysia)(Springer, 2018) Sarva Mangala PraveenaThis study was designed to determine the particle size distribution and develop road dust index combining source and transport factors involving road dust for dust pollution quantification in Rawang. Principal component analysis (PCA) was applied to identify possible sources of potentially toxic elements and spot major pollution areas in Rawang. The health risks (carcinogenic and noncarcinogenic) to adults and children were assessed using the hazard index and total lifetime cancer Risk, respectively. A total of 75 road dust samples were collected and particle sizes (1000, 500, 250, 160, 125 and 63 μm) were determined. Concentrations of potentially toxic elements (Cu, Cd, Co, Cr, Pb, Ni, Zn and As) in particle size of 63 μm were analyzed.Item Embargo Status, source identification, and health risks of potentially toxic element concentrations in road dust in a medium-sized city in a developing country(Springer, 2018) S. M. Praveena; A. Z. ArisThis study aims to determine the status of potentially toxic element concentrations of road dust in a medium-sized city (Rawang, Malaysia). This study adopts source identification via enrichment factor, Pearson correlation analysis, and Fourier spectral analysis to identify sources of potentially toxic element concentrations in road dust in Rawang City, Malaysia. Health risk assessment was conducted to determine potential health risks (carcinogenic and non-carcinogenic risks) among adults and children via multiple pathways (i.e., ingestion, dermal contact, and inhalation).Item Embargo Spatial distribution of natural γ radiation exposure and its relationship to soil types(Springer, 2016) Ahmad Termizi Ramli; Mohammad Syazwan Mohd Sanusi; Muhammad Hisyam Lee; Sallehuddin Sahrone; Nor Zati Hani Abu HanifahAn extensive survey of natural γ radiation dose rate levels was measured throughout the Melaka State, Malaysia. The main objective of the present study is to verify the influence of different soil types γ radiation exposures in air using statistical analyses. One-way analysis of variances ANOVA and post hoc test using Fisher’s least significant difference (LSD) were used to test the probability of significance difference between the dose rates and soil types. The survey involved 541 measurement points of terrestrial gamma radiation dose rates in an area of 1650 km2 which covers five major soil groups based on six FAO/UNESCO soil orders.Item Embargo 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 LatifThe 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.Item Embargo Decision analysis of multi-pollutant control strategy for coal-fired power plant in Malaysia(Springer, 2016) Mutahharah M. Mokhtar; M. Rozainee Taib; Mimi H. HassimThe promulgation of Environmental Quality (Clean Air) Regulations 2014 on emissions from coal-fired power plants in Malaysia has prompted power plant operators to adopt emission control strategy that complies with the new emission limits. Currently, various emission control strategies are available to achieve the desired emission level. Each strategy offers unique advantages and disadvantages, depending on the objective of emissions control, process nature, and constraints on the resources incurred. To address this challenge, a proper decision-making analysis needs to be performed. In this paper, a systematicdecision analysis methodology is proposed to select the most effective multipollutant control strategy that is compatible for coal-fired power plants in Malaysia.Item Embargo Relationship between land use composition and PM10 concentrations in Iskandar Malaysia(Springer, 2016) Muhammad Azahar Zikri Zahari; M. Rafee Majid; Chin Siong Ho; Gakuji Kurata; Nordin Nadhirah; Safitri Zen IrinaAir pollution has always been a concern with increasing urbanization and poor land use planning adding to the problem. This study sets out to investigate the relationship between land use composition of an area and its ambient concentration of 10 μm-or-less particulate matter (PM10). For this study, Iskandar Malaysia has been chosen as the study area. To compensate for the limited number of air quality monitoring stations in the study area, Terra MODIS aerosol optical depth Level 2 products are used to assess PM10 concentration spatially. Land use data were developed from LANDSAT images used together with the land use database from the local authority. Finally, the relationship between land use composition and concentrations of PM10 in the study area are explained using contour ternary plots. The plots show how different compositions of three major urban land uses (residential, commercial, industrial) in an area results in different concentration levels of PM10. Concentrations of PM10 are evidently more affected by commercial land use, followed by industrial land use.Item Embargo 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 SuratmanThis 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.Item Embargo Prediction of the level of air pollution using principal component analysis and artificial neural network techniques: A case study in Malaysia(Springer, 2014) Azman Azid; Hafizan Juahir; Mohd Ekhwan Toriman; Mohd Khairul Amri Kamarudin; Ahmad Shakir Mohd Saudi; Che Noraini Che Hasnam; Nor Azlina Abdul Aziz; Fazureen Azaman; Mohd Talib Latif; Syahrir Farihan Mohamed Zainuddin; Mohamad Romizan Osman; Mohammad YaminThis study focused on the pattern recognition of Malaysian air quality based on the data obtained from the Malaysian Department of Environment (DOE). Eight air quality parameters in ten monitoring stations in Malaysia for 7 years (2005-2011) were gathered. Principal component analysis (PCA) in the environmetric approach was used to identify the sources of pollution in the study locations. The combination of PCA and artificial neural networks (ANN) was developed to determine its predictive ability for the air pollutant index (API). The PCA has identified that CH4, NmHC, THC, O3, and PM10 are the most significant parameters.Item Embargo Source contribution of PM2.5 at different locations on the Malaysian Peninsula(Springer, 2015) Ooi Ee-Ling; Nur Ili Hamizah Mustaffa; Norhaniza Amil; Md Firoz Khan; Mohd Talib LatifThis study determined the source contribution of PM2.5 (particulate matter <2.5 μm) in air at three locations on the Malaysian Peninsula. PM2.5 samples were collected using a high volume sampler equipped with quartz filters. Ion chromatography was used to determine the ionic composition of the samples and inductively coupled plasma mass spectrometry was used to determine the concentrations of heavy metals. Principal component analysis with multilinear regressions were used to identify the possible sources of PM2.5.Item Embargo PM10 Pollution: Its Prediction and Meteorological Influence in PasirGudang, Johor(IOP Publishing, 2014) A Afzali; M Rashid; B Sabariah; M RamliAmbient PM10 (i.e particulate diameter less than 10 μm in size) pollution has negative impacts on human health and it is influenced by meteorological conditions. Although the correlation between meteorological parameters and PM10 concentrations is significant in most cases, the linear relationship between them implies that the fraction of the variance, R2 rarely exceeds 25%. However, considering the previous day's concentration of pollutants to the multi-linear regression enhances the model performance and increases the value of R2. Alternatively, artificial neural networks (ANN) are used to capture the complex relationships among many factors considered which present a better prediction. Thus, this study presents the results of predicting ambient PM10 concentration and the influence of meteorological parameters based on the data sampled from 2008 - 2010 in an industrial area of Pasir Gudang, Johor.Item Embargo Source identification of particulate matter in a semi-urban area of Malaysia using multivariate techniques(Springer, 2014) N. B. A. Wahid; M. T. Latif; L. S. Suan; D. Dominick; M. Sahani; S. A. Jaafar; N. Mohd TahirThis study aims to determine the composition and sources of particulate matter with an aerodynamic diameter of 10 μm or less (PM10) in a semi-urban area. PM10 samples were collected using a high volume sampler.Item Embargo The impact of urban growth on regional air quality surrounding the Langat River Basin, Malaysia(Springer, 2011) Mohd Talib Latif; Siti Zawiyah Azmi; Ahmad Daud Mohamed Noor; Aida Shafawati Ismail; Zaharizam Johny; Shaharudin Idrus; Ahmad Fariz Mohamed; Mazlin Bin MokhtarStudies of air quality were carried out in the towns of Kajang, Nilai and Banting in the Langat River Basin, southern region of Kuala Lumpur to determine the status and trend of air quality. The determination of air quality was based on several parameters such as suspended solids with diameters less than 10 μm (PM10) and gaseous pollutants of sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO). Primary concentration data of air pollutants were compiled through fieldwork studies and combined with secondary data obtained from the regular monitoring data as collected by Alam Sekitar Malaysia Sdn. Bhd. (ASMA) on behalf of Malaysian Department of Environment (DOE) at their stations in Kajang and Nilai.Item Embargo Determination of trace metals in airborne particulate matter of Kuala Terengganu, Malaysia(Springer, 2009) N. Mohd Tahir; S. C. Poh; S. Suratman; M. M. Ariffin; N. A. M. Shazali; K. YunusResults from the present study in Kuala Terengganu, Malaysia indicated a significant spatial variation but generally the total suspended particulate concentrations (mean = 17.2–148 µg/m³) recorded were below the recommended Malaysia guideline for total suspended particulate(mean of 24-h measurement = 260 µg/m³).Item Embargo Particulate matter dispersion and haze occurrence potential studies at a local palm oil mill(Springer, 2007) L. C. Abdullah; L. I. Wong; M., Saari; A. Salmiaton; M. S. Abdul RashidThe emissions from palm oil industry through incineration and open burning are the major sources of air pollutions contribution in Malaysia. The consequence of increasing the particulate concentration, the particulate matter dissolves with vapour and grows into droplets when the humidity exceeds approximately 70% and causing opaque situation known as haze. This work focuses on the dispersion particulate matter from palm oil mill. Gaussian Plume Model from a point source, subject to various atmospheric conditions is used to calculate particulate matter concentration then display the distribution of plume dispersion using geographic information system.Item Embargo 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 AbdullahChanging 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.Item Embargo A comparison of nearby incremental ground level and in plant concentrations of air pollutants emitted from electronics facilities(Springer, 2006) P. L. Law; S. C. Gracie Chong; A. Baharun; A. Abdul RahmanAir dispersion modeling by was recently conducted to predict the incremental ground level and inplant concentrations of toxic organic chemicals due to stack and fugitive emissions from Sama Jaya Free Industrial Zone (SJFIZ), Kuching, Sarawak, Malaysia. Simulations of organic air pollutants emitted from industrial facilities in SJFIZ from years 1996 to 2001 were carried out in September 2004 by members of Faculty of Engineering, Universiti Malaysia Sarawak (UNIMAS).