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Saidu AM, Garba I, Abba M, Yahuza MA, Yusuf L, Tahir NM, Garko SS. Evaluation of image quality and radiation dose in computed tomography urography following tube voltage optimisation. Radiography (Lond) 2024; 30:301-307. [PMID: 38071938 DOI: 10.1016/j.radi.2023.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/05/2023] [Accepted: 11/28/2023] [Indexed: 01/15/2024]
Abstract
INTRODUCTION Computed tomography urography (CTU) comprehensively evaluates the urinary tract. However, the procedure is associated with a high radiation dose due to multiple scan series and therefore requires optimisation. The study performed CTU protocol optimisation based on a reduction in tube voltage (kV) using quality assurance (QA) phantom and clinical images and evaluated image quality and radiation dose. METHODS The study was prospectively conducted on patients referred for CTU. The patients were grouped into A and B and were scanned with the standard protocol, a protocol used for the routine CTU at the CT centre before optimisation, and optimised protocol, a protocol with reduced kV respectively. The protocols were first tried on a quality assurance (QA) phantom before being applied to patients, and image quality was assessed based on signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). In addition, the clinical images were assessed based on the visibility of the anatomical criteria for CT images by five observers with >5 years of experience. The data were analysed using both visual grading characteristic (VGC) curves and statistical package for social sciences (SPSS) version 22.0. RESULTS The dose was significantly lower in the optimised protocol with a 10 % reduction in both volume computed tomography dose index and (CTDIvol) and dose length product (DLP) for the phantom images, and a 26 % reduction in CTDIvol and 28 % in DLP for the clinical images. However, there was no significant difference in image quality noted between the standard and optimised protocols based on the quantitative and qualitative image quality evaluation using both the QA phantom and clinical images. CONCLUSION The findings revealed a significant dose reduction in the optimised protocol. Further, image quality in standard and optimised protocols did not differ significantly based on quantitative and qualitative methods. IMPLICATION FOR PRACTICE kV optimisation in contrast-enhanced procedures provides dose reduction and should be encouraged in the medical imaging departments.
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Affiliation(s)
- A M Saidu
- Department of Medical Radiography, Faculty of Allied Health Sciences, College of Health Sciences, Bayero University Kano, Nigeria
| | - I Garba
- Department of Medical Radiography, Faculty of Allied Health Sciences, College of Health Sciences, Bayero University Kano, Nigeria.
| | - M Abba
- Department of Medical Radiography, Faculty of Allied Health Sciences, College of Health Sciences, Bayero University Kano, Nigeria
| | - M A Yahuza
- Department of Radiology, Faculty of Clinical Sciences, College of Health Sciences, Bayero University Kano, Nigeria
| | - L Yusuf
- Department of Radiology, Faculty of Clinical Sciences, College of Health Sciences, Bayero University Kano, Nigeria
| | - N M Tahir
- Radiology Department, Orthopaedic Hospital, Dala, Kano State Nigeria
| | - S S Garko
- Radiology Department, Orthopaedic Hospital, Dala, Kano State Nigeria
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Pang SY, Suratman S, Tay JH, Tan HS, Mohd Tahir N. Spatial and temporal trends of polycyclic aromatic hydrocarbons in sediment cores of Brunei Bay, East Malaysia. Mar Pollut Bull 2022; 179:113670. [PMID: 35525058 DOI: 10.1016/j.marpolbul.2022.113670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 04/05/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
The spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in three sediment cores from Brunei Bay, Southern South China Sea was investigated. The total concentrations of 16 priority PAHs (∑PAH16) and their alkyl-substituted derivatives ranged from 10.4 to 376 ng g-1 and 30.7 to 2263 ng g-1, respectively. PAH biomarker diagnostic ratios and principal component analysis (PCA) combined with absolute principal component score (APCS) and multiple linear regression (MLR) were performed to apportion the source contribution. The results revealed mixed inputs of fuel combustion residues and uncombusted petrogenic products. The downcore PAH profile revealed that the highest peaks could be related to past human activities using biofuel and coal during the industrialization/agriculture revolution period. The 1,7/(2,6+1,7)-dimethylphenanthrene ratio also highlighted wood combustion during forest fire outbreaks, which appeared to coincide with the past climate events.
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Affiliation(s)
- Swee Yun Pang
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor, Malaysia.
| | - Suhaimi Suratman
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Joo Hui Tay
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia
| | - Hock Seng Tan
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Norhayati Mohd Tahir
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
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Pang SY, Suratman S, Latif MT, Khan MF, Simoneit BRT, Mohd Tahir N. Polycyclic aromatic hydrocarbons in coastal sediments of Southern Terengganu, South China Sea, Malaysia: source assessment using diagnostic ratios and multivariate statistic. Environ Sci Pollut Res Int 2022; 29:15849-15862. [PMID: 34636003 DOI: 10.1007/s11356-021-16762-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
Surface sediments along the Southern Terengganu coast (≤7 km from the coast) were analyzed for polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 USEPA priority polycyclic aromatic hydrocarbons (ΣPAH16) ranged from 2.59 to 155 ng g-1 and their respective alkylated ranged between 8.80 and 24.90 ng g-1. Traces of acephenanthrylene, benzo[c]phenanthrene, thiophenic PAH, and benzonaphthofuran were identified. PAH diagnostic ratios and cross-plots revealed that these sedimentary PAH compounds are derived mainly from pyrogenic sources, primarily from biomass burning and petroleum combustion residues with minor petrogenic input. The high correlations between pyrogenic PAHs to total PAHs (r >0.73, p <0.5), and the Bap/Bep ratio to total PAHs (r = 0.88, p <0.5), suggest that atmospheric deposition and urban runoff are the main deposition pathways. The concentrations of the PAHs in the southern South China Sea fall in the moderate contamination range of 100-1000 ng g-1.
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Affiliation(s)
- Swee Yun Pang
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030, K. Nerus, Terengganu, Malaysia.
| | - Suhaimi Suratman
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030, K. Nerus, Terengganu, Malaysia
| | - Mohd Talib Latif
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Md Firoz Khan
- Department of Chemistry, Faculty of Science, University of Malaya, W. Persekutuan Kuala Lumpur, 50603, Kuala Lumpur, Malaysia
| | - Bernd R T Simoneit
- Department of Chemistry, College of Science, Oregon State University, Corvallis, OR, 97331, USA
| | - Norhayati Mohd Tahir
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030, K. Nerus, Terengganu, Malaysia
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030, K. Nerus, Terengganu, Malaysia
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Pang SY, Suratman S, Tay JH, Mohd Tahir N. Investigation of aliphatic hydrocarbons in core sediments of Brunei Bay, East Malaysia. Mar Pollut Bull 2021; 171:112736. [PMID: 34325152 DOI: 10.1016/j.marpolbul.2021.112736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 07/11/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
The distribution of aliphatic hydrocarbons in three sediment cores from Brunei Bay was investigated in order to understand their sources and the biogeochemical processes of these hydrocarbons. The total concentrations of C15 to C37n-alkanes ranged from 0.70 to 16.5 μg g-1. Traces of hopanes with C29-C31 carbon homologs were detected in the study area. The carbon preference index (CPI15-37) ranged from 1.23 to 3.42 coupled with the natural n-alkane ratio (NAR19-32) ratios (1.52 to 5.34), and the presence of unresolved complex mixtures and hopanes, suggested slight contamination by anthropogenic hydrocarbons, presumably derived from activities along the coasts. The presence of C27 trisnorhopene and diploptene, as well as their association with long-chain and short-chain n-alkanes, revealed a depositional environment of organic matter in the sediment cores.
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Affiliation(s)
- Swee Yun Pang
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.
| | - Suhaimi Suratman
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Joo Hui Tay
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia
| | - Norhayati Mohd Tahir
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
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Pang SY, Suratman S, Hii YS, Simoneit BR, Mohd Tahir N. Sources of Polycyclic Aromatic Hydrocarbons in South China Sea Short Core Sediments Off Southern Part Terengganu, Malaysia and Multivariate Statistics Approaches. SAINS MALAYS 2021. [DOI: 10.17576/jsm-2021-5009-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sediment cores from the southern South China Sea off the Terengganu coast were analyzed for polycyclic aromatic hydrocarbons (PAH s) and perylene. The concentrations of total 17 PAH (TPAHs) and perylene varied between 5.45-27.7 ng/g and 0.51-7.77 ng/g, respectively. Analyses of variance showed significant differences between the stations, but not in sub-bottom depths at the 0.05 level. The PAH cross plots showed a predominance of pyrogenic over petrogenic PAH s. Principal component analysis (PCA) showed clustered PAH s that are correlated with total organic carbon (TOC), indicating the importance of surface runoff via fluvial transport for contributing these PAH s to the coastal environment of the study area. Overall, the concentrations of PAH s in the study area are considered to be in the low range, not exceeding the 100 ng/g mark.
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Kong SR, Yamamoto M, Shaari H, Hayashi R, Seki O, Mohd Tahir N, Fadzil MF, Sulaiman A. The significance of pyrogenic polycyclic aromatic hydrocarbons in Borneo peat core for the reconstruction of fire history. PLoS One 2021; 16:e0256853. [PMID: 34495997 PMCID: PMC8425563 DOI: 10.1371/journal.pone.0256853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 08/18/2021] [Indexed: 11/25/2022] Open
Abstract
The reconstruction of fire history is essential to understand the palaeoclimate and human history. Polycyclic aromatic hydrocarbons (PAHs) have been extensively used as a fire marker. In this work, the distribution of PAHs in Borneo peat archives was investigated to understand how PAHs reflect the palaeo-fire activity. In total, 52 peat samples were analysed from a Borneo peat core for the PAH analysis. Pyrogenic PAHs consist of 2–7 aromatic rings, some of which have methyl and ethyl groups. The results reveal that the concentration of pyrogenic PAHs fluctuated with the core depth. Compared to low-molecular-weight (LMW) PAHs, the high-molecular-weight (HMW) PAHs had a more similar depth variation to the charcoal abundance. This finding also suggests that the HMW PAHs were mainly formed at a local fire near the study area, while the LMW PAHs could be transported from remote locations.
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Affiliation(s)
- Sher-Rine Kong
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- * E-mail: (HS); (SRK); (MY)
| | - Masanobu Yamamoto
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- * E-mail: (HS); (SRK); (MY)
| | - Hasrizal Shaari
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
- * E-mail: (HS); (SRK); (MY)
| | | | - Osamu Seki
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Norhayati Mohd Tahir
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Muhammad Fais Fadzil
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Abdullah Sulaiman
- Department of Mineral and Geoscience, Kedah, Kuala Terengganu, Malaysia
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Pang SY, Tay JH, Suratman S, Simoneit BRT, Mohd Tahir N. Input of organic matter in Brunei Bay, East Malaysia, as indicated by sedimentary steroids and multivariate statistics. Mar Pollut Bull 2020; 156:111269. [PMID: 32510409 DOI: 10.1016/j.marpolbul.2020.111269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 05/01/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
Brunei Bay is one of the most important marine environments of East Malaysia (South China Sea), covering many productive ecosystems with activities including fisheries, tourism, and main shipping lanes for petroleum transfers. Evaluation of the sources and distributions of steroids in the surface sedimentary organic matter was carried out by gas chromatography-mass spectrometry (GC-MS). The concentrations of the total identified sterols (TIS) ranged between 0.81 and 12.69 μg g-1 dry weight, and the total sterones were between 0.11 and 5.66 μg g-1 dry weight. The coprostanol level was comparatively low (<0.10 μg g-1), and the multi-biomarker proxies indicated that the region did not exhibit significant contamination from sewage effluents. Principal component analysis (PCA) revealed the coastal environment of the study area was dominated by allochthonous (mainly terrestrial) organic matter input.
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Affiliation(s)
- Swee Yun Pang
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.
| | - Joo Hui Tay
- Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Malaysia
| | - Suhaimi Suratman
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Bernd R T Simoneit
- Department of Chemistry, College of Science, Oregon State University, Corvallis, OR 97331, USA
| | - Norhayati Mohd Tahir
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.
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Sulong NA, Latif MT, Sahani M, Khan MF, Fadzil MF, Tahir NM, Mohamad N, Sakai N, Fujii Y, Othman M, Tohno S. Distribution, sources and potential health risks of polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 collected during different monsoon seasons and haze episode in Kuala Lumpur. Chemosphere 2019. [PMID: 30528968 DOI: 10.1016/j.scitotenv.2017.05.15310.1016/j.chemosphere.2018.11.195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This study aimed to determine the distribution and potential health risks of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 collected in Kuala Lumpur during different monsoon seasons. The potential sources of PM2.5 were investigated using 16 priority PAHs with additional of biomass tracers namely levoglucosan (LV), mannosan (MN) and galactosan (GL). This study also investigated the cytotoxic potential of the extracted PAHs towards V79-4 cells. A high-volume air sampler (HVS) was used to collect PM2.5 samples for 24 h. PAHs were extracted using dichloromethane (DCM) while biomass tracers were extracted by a mixture of DCM/methanol (3:1) before analysis with gas chromatography-mass spectrometry (GC-MS). The cytotoxicity of the PAHs extract was determined by assessing the cell viability through the reduction of tetrazolium salts (MTT). The results showed that the total mean ± SD concentrations of PAHs during the southwest (SW) and northeast (NE) monsoons were 2.51 ± 0.93 ng m-3 and 1.37 ± 0.09 ng m-3, respectively. Positive matrix factorization (PMF) using PAH and biomass tracer concentrations suggested four potential sources of PM2.5; gasoline emissions (29.1%), natural gas and coal burning (28.3%), biomass burning (22.3%), and diesel and heavy oil combustion (20.3%). Health risk assessment showed insignificant incremental lifetime cancer risk (ILCR) of 2.40E-07 for 70 years of exposure. MTT assay suggested that PAHs extracts collected during SW monsoon have cytotoxic effect towards V79-4 cell at the concentrations of 25 μg mL-1, 50 μg mL-1, 100 μg mL-1 whereas non-cytotoxic effect was observed on the PAHs sample collected during NE monsoon.
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Affiliation(s)
- Nor Azura Sulong
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Mohd Talib Latif
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
| | - Mazrura Sahani
- Centre for Health and Applied Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Md Firoz Khan
- Centre for Tropical Climate Change System, Institute for Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Muhammad Fais Fadzil
- Environmental Research Group, School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Norhayati Mohd Tahir
- Environmental Research Group, School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Noorlin Mohamad
- Environmental Research Group, School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Nobumitsu Sakai
- Department of Environmental Engineering, Kyoto University, 4, Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Yusuke Fujii
- Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Murnira Othman
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Susumu Tohno
- Department of Socio-Environmental Energy Science, Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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Sulong NA, Latif MT, Sahani M, Khan MF, Fadzil MF, Tahir NM, Mohamad N, Sakai N, Fujii Y, Othman M, Tohno S. Distribution, sources and potential health risks of polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 collected during different monsoon seasons and haze episode in Kuala Lumpur. Chemosphere 2019; 219:1-14. [PMID: 30528968 DOI: 10.1016/j.chemosphere.2018.11.195] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 11/24/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
This study aimed to determine the distribution and potential health risks of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 collected in Kuala Lumpur during different monsoon seasons. The potential sources of PM2.5 were investigated using 16 priority PAHs with additional of biomass tracers namely levoglucosan (LV), mannosan (MN) and galactosan (GL). This study also investigated the cytotoxic potential of the extracted PAHs towards V79-4 cells. A high-volume air sampler (HVS) was used to collect PM2.5 samples for 24 h. PAHs were extracted using dichloromethane (DCM) while biomass tracers were extracted by a mixture of DCM/methanol (3:1) before analysis with gas chromatography-mass spectrometry (GC-MS). The cytotoxicity of the PAHs extract was determined by assessing the cell viability through the reduction of tetrazolium salts (MTT). The results showed that the total mean ± SD concentrations of PAHs during the southwest (SW) and northeast (NE) monsoons were 2.51 ± 0.93 ng m-3 and 1.37 ± 0.09 ng m-3, respectively. Positive matrix factorization (PMF) using PAH and biomass tracer concentrations suggested four potential sources of PM2.5; gasoline emissions (29.1%), natural gas and coal burning (28.3%), biomass burning (22.3%), and diesel and heavy oil combustion (20.3%). Health risk assessment showed insignificant incremental lifetime cancer risk (ILCR) of 2.40E-07 for 70 years of exposure. MTT assay suggested that PAHs extracts collected during SW monsoon have cytotoxic effect towards V79-4 cell at the concentrations of 25 μg mL-1, 50 μg mL-1, 100 μg mL-1 whereas non-cytotoxic effect was observed on the PAHs sample collected during NE monsoon.
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Affiliation(s)
- Nor Azura Sulong
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Mohd Talib Latif
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
| | - Mazrura Sahani
- Centre for Health and Applied Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Md Firoz Khan
- Centre for Tropical Climate Change System, Institute for Climate Change, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Muhammad Fais Fadzil
- Environmental Research Group, School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Norhayati Mohd Tahir
- Environmental Research Group, School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Noorlin Mohamad
- Environmental Research Group, School of Marine and Environmental Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
| | - Nobumitsu Sakai
- Department of Environmental Engineering, Kyoto University, 4, Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Yusuke Fujii
- Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Murnira Othman
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Susumu Tohno
- Department of Socio-Environmental Energy Science, Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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Hee YY, Suratman S, Mohd Tahir N, Jickells T. Seasonal Variability and Fractionation of P-Based Nutrients in Setiu River Basin, Terengganu, Malaysia. SAINS MALAYS 2018. [DOI: 10.17576/jsm-2018-4705-03] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Suratman S, Abdul Aziz A, Mohd Tahir N, Lee LH. Distribution and Behaviour of Nitrogen Compounds in the Surface Water of the Sungai Terengganu Estuary, Southern Waters of South China Sea, Malaysia. SAINS MALAYS 2018. [DOI: 10.17576/jsm-2018-4704-02] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Suratman S, Che Zan NH, Abdul Aziz A, Mohd Tahir N. Spatial and Seasonal Variations of Organic Carbon-Based Nutrients in Setiu Wetland, Malaysia. SAINS MALAYS 2017. [DOI: 10.17576/jsm-2017-4606-04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Pang SY, Ariffin J, Hii YS, Mohd Tahir N. Influence of Monsoon on the Distribution of Organic Carbon in Inner Continental Shelf Core Sediments, South China Sea, Malaysia. SAINS MALAYS 2015. [DOI: 10.17576/jsm-2015-4407-04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Jaafar SA, Latif MT, Chian CW, Han WS, Wahid NBA, Razak IS, Khan MF, Tahir NM. Surfactants in the sea-surface microlayer and atmospheric aerosol around the southern region of Peninsular Malaysia. Mar Pollut Bull 2014; 84:35-43. [PMID: 24930738 DOI: 10.1016/j.marpolbul.2014.05.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/18/2014] [Accepted: 05/19/2014] [Indexed: 06/03/2023]
Abstract
This study was conducted to determine the composition of surfactants in the sea-surface microlayer (SML) and atmospheric aerosol around the southern region of the Peninsular Malaysia. Surfactants in samples taken from the SML and atmospheric aerosol were determined using a colorimetric method, as either methylene blue active substances (MBAS) or disulphine blue active substances (DBAS). Principal component analysis with multiple linear regressions (PCA-MLR), using the anion and major element composition of the aerosol samples, was used to determine possible sources of surfactants in atmospheric aerosol. The results showed that the concentrations of surfactants in the SML and atmospheric aerosol were dominated by anionic surfactants and that surfactants in aerosol were not directly correlated (p>0.05) with surfactants in the SML. Further PCA-MLR from anion and major element concentrations showed that combustion of fossil fuel and sea spray were the major contributors to surfactants in aerosol in the study area.
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Affiliation(s)
- Shoffian Amin Jaafar
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Mohd Talib Latif
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System, Institute for Climate Change (IKLIM), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
| | - Chong Woan Chian
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Wong Sook Han
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Nurul Bahiyah Abd Wahid
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Department of Biology, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak, Malaysia
| | - Intan Suraya Razak
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Md Firoz Khan
- School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia; Centre for Tropical Climate Change System, Institute for Climate Change (IKLIM), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Norhayati Mohd Tahir
- Institute of Oceanography and Environment, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia; Environmental Research Group, School of Marine Science and Environment, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
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Tay JH, Jaafar S, Mohd Tahir N. Ionic composition of rainwater at selected sites of Kuantan, Pahang, Malaysia: a preliminary study. Bull Environ Contam Toxicol 2014; 92:329-333. [PMID: 24435136 DOI: 10.1007/s00128-014-1203-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 01/08/2014] [Indexed: 06/03/2023]
Abstract
A short-term investigation on the chemical composition of rainwater was carried out at five selected sampling stations in Kuantan district, Pahang, Malaysia. Sampling of rainwater was conducted by event basis between September and November 2011. Rainwater samples were collected using polyethylene containers and the parameters measured were cations (sodium, potassium, ammonium, calcium and magnesium) and anions (chlorides, nitrates and sulphates). The average pH value for rainwater samples was 6.0 ± 0.57 in which most of the sampling sites exhibited pH values >5.6. Calcium and sulphate were the most abundant cation and anion, respectively, whilst the concentrations of other major ions varied according to sampling location.
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Affiliation(s)
- Joo Hui Tay
- Faculty of Industrial Sciences and Technology (FIST), Universiti Malaysia Pahang (UMP), Lebuhraya Tun Razak, 26300, Gambang, Kuantan, Pahang, Malaysia,
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Koh MK, Sathiamurthy E, Suratman S, Tahir NM. Sandbar-regulated hydrodynamic influences on river hydrochemistry at Mengabang Telipot River, Peninsular Malaysia. Environ Monit Assess 2012; 184:7653-7664. [PMID: 22302401 DOI: 10.1007/s10661-012-2525-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 01/11/2012] [Indexed: 05/31/2023]
Abstract
Influences of river hydrodynamic behaviours on hydrochemistry (salinity, pH, dissolved oxygen saturations and dissolved phosphorus) were evaluated through high spatial and temporal resolution study of a sandbar-regulated coastal river. River hydrodynamic during sandbar-closed event was characterized by minor dependency on tidal fluctuations, very gradual increase of water level and continual low flow velocity. These hydrodynamic behaviours established a hydrochemistry equilibrium, in which water properties generally were characterized by virtual absence of horizontal gradients while vertical stratifications were significant. In addition, the river was in high trophic status as algae blooms were visible. Conversely, river hydrodynamic in sandbar-opened event was tidal-controlled and showed higher flow velocity. Horizontal gradients of water properties became significant while vertically more homogenised and with lower trophic status. In essence, this study reveals that estuarine sandbar directly regulates river hydrodynamic behaviours which in turn influences river hydrochemistry.
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Affiliation(s)
- Mei Kee Koh
- Institute of Oceanography, University Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia
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Tahir NM, Rahim HMA, Hui TJ, Seng TH, Fadzil MF, Abas MR. Distribution and sources of hydrocarbons in lagoon sediments of Setiu Wetland, Terengganu, Malaysia. Aquatic Ecosystem Health & Management 2009; 12:344-349. [DOI: 10.1080/14634980903361820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Hydrocarbon compounds viz. aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), sterols, long chain fatty acids, alkanones and alkanals in surface sediment of Setiu Wetland were analysed and characterized using GCMS. The concentration of total identified resolved n-alkanes (TIRNA) in sediment ranged from 2.99–11.6 μ g g− 1 dry weight. The distribution of the aliphatic fraction showed the presence of n-alkanes ranging from C12 to C36 with high predominance for long chain homologues (C25-C31) and a carbon maximum at C29 and C31 with CPI > 3; these observations provide evidence for the presence of biogenic terrigenous input corresponding to epicuticular plant waxes into the lagoon sediments. Positive and strong correlation between n-alkanes associated with terrigenous input (ALK TER) and TIRNA suggest terrestrial input is the main sources of TIRNA in this study area. The absence of unresolved complex mixture (UCM) in the chromatogram and the absence of hopanes, steranes and PAHs compounds are indicative of uncontaminated sediment by petrogenic and pyrogenic hydrocarbons. The concentration of total identified sterols (TIS) ranged from 1.41 μ g g− 1 dry weight to 3.11 μ g g− 1 dry weight with cholesterol, β -Sitosterol and stigmasterol were generally the most dominant and abundant components detected at almost all stations. A positive and strong correlation was observed between B-Sitosterol and TIS and the distribution of long chain n-alkan-2-ones in the range of C21 to C27 with odd to even predominance and n-alkanals (C20 to C28), n-alkanols (C22–C30) and n-alkanoic acids (C22–C30) with even to odd predominance provide further evidence for biogenic sources of hydrocarbons with terrestrial plant input as the predominant source. It was noted that a minor contribution associated with marine phytoplankton (algae) as well as bacteria were also observed in some of the sediment samples superimposing with the terrigenous plant wax input. In general results from this study clearly showed the lagoon sediment of Setiu Wetland is still in uncontaminated condition where terrestrial plants input are the dominant contributor of organic compounds in the sediments with a minor input from marine organisms.
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Affiliation(s)
- Norhayati Mohd Tahir
- Environmental Research Group (ERG), Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), Mengabang Telipot, 21030 Kuala Terengganu
| | - Hasra Masrifah Abd. Rahim
- Environmental Research Group (ERG), Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), Mengabang Telipot, 21030 Kuala Terengganu
| | - Tay Joo Hui
- Environmental Research Group (ERG), Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), Mengabang Telipot, 21030 Kuala Terengganu
| | - Tan Hock Seng
- Environmental Research Group (ERG), Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), Mengabang Telipot, 21030 Kuala Terengganu
| | - Muhammad Fais Fadzil
- Environmental Research Group (ERG), Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), Mengabang Telipot, 21030 Kuala Terengganu
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Suhaimi S, Tahir NM, Suriyati S. Dissolved nutrients and chlorophyll a status of the Setiu River, Terengganu, Malaysia. Bull Environ Contam Toxicol 2004; 73:1094-1100. [PMID: 15674725 DOI: 10.1007/s00128-004-0537-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- S Suhaimi
- Department of Chemical Sciences, Faculty of Science and Technology, University College of Science and Technology Malaysia (KUSTEM), 21030 Kuala Terengganu, Terengganu, Malaysia
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Bin Abas M, Takruni IA, Abdullah Z, Tahir NM. Erratum to “On-line preconcentration and determination of trace metals using a flow injection system coupled to ion chromatography”. Talanta 2002. [DOI: 10.1016/s0039-9140(02)00544-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bin Abas MR, Takruni IA, Abdullah Z, Tahir NM. On-line preconcentration and determination of trace metals using a flow injection system coupled to ion chromatography. Talanta 2002; 58:883-890. [PMID: 18968820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2002] [Revised: 07/29/2002] [Accepted: 07/29/2002] [Indexed: 05/27/2023]
Abstract
A flow injection (FI) method with on-line preconcentration using a mini-column loaded with 8-hydroxyquinoline immobilized on controlled pore glass (CPG-8HQ) is described for the determination of trace metals by ion chromatography (IC) with pyridine-2-6-dicarboxylic acid (PDCA) as the eluent. Copper, cadmium, lead, zinc, nickel and iron were determined at ppb level after post-column derivatization with 4-(2-pyridylazo)-resorcinol (PAR). The detection limits (3sigma) for the FI/IC system were 8.27, 0.89, 0.09, 0.06, 0.09 and 0.07 g l(-1) for Pb(2+), Cd(2+), Cu(2+) Ni(2+), Zn(2+) and Fe(3+), respectively, using 5 ml sample volume. The method was applied to the analysis of Malaysian natural waters.
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Affiliation(s)
- M Radzi Bin Abas
- Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Abdullah AR, Sinnakkannu S, Tahir NM. Adsorption, desorption, and mobility of metsulfuron methyl in Malaysian agricultural soils. Bull Environ Contam Toxicol 2001; 66:762-769. [PMID: 11353379 DOI: 10.1007/s001280074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2000] [Accepted: 03/14/2001] [Indexed: 05/23/2023]
Affiliation(s)
- A R Abdullah
- Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Abdullah AR, Tahir NM, Wei LK. Hydrocarbons in seawater and sediment from the west coast of Peninsular Malaysia. Bull Environ Contam Toxicol 1994; 53:618-626. [PMID: 8000192 DOI: 10.1007/bf00199035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- A R Abdullah
- Department of Chemistry, University of Malaya, Kuala Lumpur
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