Displaying publications 61 - 80 of 193 in total

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  1. Mirmohammadi M, Hakimi Ibrahim M, Ahmad A, Kadir MO, Mohammadyan M, Mirashrafi SB
    Environ Monit Assess, 2010 Jun;165(1-4):341-7.
    PMID: 19444630 DOI: 10.1007/s10661-009-0950-5
    Today, many raw materials used in factories may have a dangerous effect on the physiological system of workers. One of them which is widely used in the polyurethane factories is diisocyanates. These compounds are widely used in surface coatings, polyurethane foams, adhesives, resins, elastomers, binders, and sealants. Exposure to diisocyanates causes irritation to the skin, mucous membranes, eyes, and respiratory tract. Hexamethylene diamine (HDA) is metabolite of hexamethylene diisocyanate (HDI). It is an excretory material by worker's urine who is exposed to HDI. Around 100 air samples were collected from five defined factories by midget impinger which contained dimethyl sulfoxide absorbent as a solvent and tryptamine as reagent. Samples were analyzed by high-performance liquid chromatography with EC\UV detector using NIOSH 5522 method of sampling. Also, 50 urine samples collected from workers were also analyzed using William's biological analysis method. The concentration of HDI into all air samples were more than 88 microg/m(3), and they have shown high concentration of pollutant in the workplaces in comparison with NIOSH standard, and all of the workers' urine were contaminated by HDA. The correlation and regression test were used to obtain statistical model for HDI and HDA, which is useful for the prediction of diisocyanates pollution situation in the polyurethane factories.
    Matched MeSH terms: Air Pollutants, Occupational/analysis*; Air Pollutants, Occupational/urine
  2. Mohd Tahir N, Poh SC, Suratman S, Ariffin MM, Shazali NA, Yunus K
    Bull Environ Contam Toxicol, 2009 Aug;83(2):199-203.
    PMID: 19436928 DOI: 10.1007/s00128-009-9751-3
    Results from the present study in Kuala Terengganu, Malaysia indicated a significant spatial variation but generally the total suspended particulate concentrations (mean = 17.2-148 microg/m(3)) recorded were below the recommended Malaysia guideline for total suspended particulate (mean of 24-h measurement = 260 microg/m(3)). Some of the elemental composition of particulate aerosol is clearly affected by non crustal sources, e.g. vehicular emission sources. Based on correlation and enrichment analyses, the elements could be grouped into two i.e. Pb, Cd and Zn group with sources from vehicular emission (r > 0.6; enrichment factor > 10) and Al, Fe, Mn and Cr group that appears to be of crustal origin (r > 0.6; enrichment factor < 10). It can also be concluded that the mean levels of Pb (1 ng/m(3)), Cd (0.02 ng/m(3)) and Zn (2 ng/m(3)) in the study area are generally lower than other urban areas in Malaysia (Pb < 181 ng/m(3); Cd < 6 ng/m(3); Zn < 192 ng/m(3)).
    Matched MeSH terms: Air Pollutants/analysis; Air Pollutants/chemistry*
  3. Dahlan I, Lee KT, Kamaruddin AH, Mohamed AR
    Environ Sci Technol, 2006 Oct 01;40(19):6032-7.
    PMID: 17051796
    Siliceous materials such as rice husk ash (RHA) have potential to be utilized as high performance sorbents for the flue gas desulfurization process in small-scale industrial boilers. This study presents findings on identifying the key factorfor high desulfurization activity in sorbents prepared from RHA. Initially, a systematic approach using central composite rotatable design was used to develop a mathematical model that correlates the sorbent preparation variables to the desulfurization activity of the sorbent. The sorbent preparation variables studied are hydration period, x1 (6-16 h), amount of RHA, x2 (5-15 g), amount of CaO, x3 (2-6 g), amount of water, x4 (90-110 mL), and hydration temperature, x5 (150-250 degrees C). The mathematical model developed was subjected to statistical tests and the model is adequate for predicting the SO2 desulfurization activity of the sorbent within the range of the sorbent preparation variables studied. Based on the model, the amount of RHA, amount of CaO, and hydration period used in the preparation step significantly influenced the desulfurization activity of the sorbent. The ratio of RHA and CaO used in the preparation mixture was also a significant factor that influenced the desulfurization activity of the sorbent. A RHA to CaO ratio of 2.5 leads to the formation of specific reactive species in the sorbent that are believed to be the key factor responsible for high desulfurization activity in the sorbent. Other physical properties of the sorbent such as pore size distribution and surface morphology were found to have insignificant influence on the desulfurization activity of the sorbent.
    Matched MeSH terms: Air Pollutants/isolation & purification*; Air Pollutants/chemistry
  4. Ismail B, Redzuwan Y, Chua RS, Shafiee W
    Appl Radiat Isot, 2001 Mar;54(3):393-7.
    PMID: 11214872
    The processing of amang (one of a number of tin-tailing products) for its valuable minerals has associated with the radiological and environmental problems. The processing and stockpiling of amang and ilmenite in open-air spaces, subject as it is to environmental influences, gives rise to a potential for affecting residents in adjacent area. A case study was carried out in a residential area neighbouring a typical amang plant to investigate the radiological impact to the residents. The average Effective Dose rates, calculated based on the contributions of Effective Dose rates from inhaled suspended radioactive dust, radon-thoron and their progeny, and external gamma radiation, were determined for selected houses. Results show that the occupants of those houses received Effective Dose rate, which cannot be differentiated from background. The major contributor to the average Effective Dose rate came from external radiation sources. Inhaled radon and its progeny was the second major contributor.
    Matched MeSH terms: Air Pollutants, Radioactive/adverse effects*; Air Pollutants, Radioactive/analysis
  5. Hamsan H, Ho YB, Zaidon SZ, Hashim Z, Saari N, Karami A
    Sci Total Environ, 2017 Dec 15;603-604:381-389.
    PMID: 28633115 DOI: 10.1016/j.scitotenv.2017.06.096
    Tanjung Karang, Selangor, is widely known for its paddy cultivation activity and hosts the third largest paddy field in Malaysia. Pesticides contamination in agriculture fields has become an unavoidable problem, as pesticides are used to increase paddy productivity and reduce plant disease. Human exposure to agrichemicals is common and could results in both acute and chronic health effects, such as acute and chronic neurotoxicity. This study aims to determine the concentrations of commonly used pesticides (azoxystrobin, buprofezin, chlorantraniliprole, difenoconazole, fipronil, imidacloprid, isoprothiolane, pretilachlor, propiconazole, pymetrozine, tebuconazole, tricyclazole, and trifloxystrobin) in personal air samples and their associated health risks among paddy farmers. Eighty-three farmers from Tangjung Karang, Selangor were involved in this study. A solid sorbent tube was attached to the farmer's breathing zone with a clip, and an air pump was fastened to the belt to collect personal air samples. Pesticides collected in the XAD-2 resin were extracted with acetone, centrifuged, concentrated via nitrogen blowdown and reconstituted with 1mL of 3:1 ultrapure water/HPLC-grade methanol solution. The extract was analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The target compounds were detected with a maximum concentration reaching up to 462.5ngm-3 (fipronil). The hazard quotient (HQ) was less than 1 and the hazard index (HI) value was 3.86×10-3, indicating that the risk of pesticides related diseases was not significant. The lifetime cancer risk (LCR) for pymetrozine was at an acceptable level (LCR<10-6) with 4.10×10-8. The results reported in this study can be beneficial in terms of risk management within the agricultural community.
    Matched MeSH terms: Air Pollutants/adverse effects; Air Pollutants/analysis*
  6. Pan KL, Pan GT, Chong S, Chang MB
    J Environ Sci (China), 2018 Jul;69:205-216.
    PMID: 29941256 DOI: 10.1016/j.jes.2017.10.012
    Double perovskite-type catalysts including La2CoMnO6 and La2CuMnO6 are first evaluated for the effectiveness in removing volatile organic compounds (VOCs), and single perovskites (LaCoO3, LaMnO3, and LaCuO3) are also tested for comparison. All perovskites are tested with the gas hourly space velocity (GHSV) of 30,000hr-1, and the temperature range of 100-600°C for C7H8 removal. Experimental results indicate that double perovskites have better activity if compared with single perovskites. Especially, toluene (C7H8) can be completely oxidized to CO2 at 300°C as La2CoMnO6 is applied. Characterization of catalysts indicates that double perovskites own unique surface properties and are of higher amounts of lattice oxygen, leading to higher activity. Additionally, apparent activation energy of 68kJ/mol is calculated using Mars-van Krevelen model for C7H8 oxidation with La2CoMnO6 as catalyst. For durability test, both La2CoMnO6 and La2CuMnO6 maintain high C7H8 removal efficiencies of 100% and 98%, respectively, at 300°C and 30,000hr-1, and they also show good resistance to CO2 (5%) and H2O(g) (5%) of the gas streams tested. For various VOCs including isopropyl alcohol (C3H8O), ethanal (C2H4O), and ethylene (C2H4) tested, as high as 100% efficiency could be achieved with double perovskite-type catalysts operated at 300-350°C, indicating that double perovskites are promising catalysts for VOCs removal.
    Matched MeSH terms: Air Pollutants/analysis; Air Pollutants/chemistry*
  7. Kouidhi W, Thannimalay L, Soon CS, Ali Mohd M
    Int J Occup Med Environ Health, 2017 Jul 14;30(5):743-750.
    PMID: 28584331 DOI: 10.13075/ijomeh.1896.00917
    OBJECTIVES: The purpose of this study has been to assess ambient bisphenol A (BPA) levels in workplaces and urine levels of workers and to establish a BPA database for different populations in Malaysia.

    MATERIAL AND METHODS: Urine samples were collected from plastic factory workers and from control subjects after their shift. Air samples were collected using gas analyzers from 5 sampling positions in the injection molding unit work area and from ambient air. The level of BPA in airborne and urine samples was quantified by the gas chromatography mass spectrometry - selected ion monitoring (GCMS-SIM) analysis.

    RESULTS: Bisphenol A was detected in the median range of 8-28.3 ng/m³ and 2.4-3.59 ng/m³ for the 5 sampling points in the plastic molding factory and in the ambient air respectively. The median urinary BPA concentration was significantly higher in the workers (3.81 ng/ml) than in control subjects (0.73 ng/ml). The urinary BPA concentration was significantly associated with airborne BPA levels (ρ = 0.55, p < 0.01).

    CONCLUSIONS: Our findings provide the first evidence that workers in a molding factory in Malaysia are occupationally exposed to BPA. Int J Occup Med Environ Health 2017;30(5):743-750.

    Matched MeSH terms: Air Pollutants, Occupational/analysis*; Air Pollutants, Occupational/urine
  8. Azam M, Khan AQ, Bin Abdullah H, Qureshi ME
    Environ Sci Pollut Res Int, 2016 Apr;23(7):6376-89.
    PMID: 26620862 DOI: 10.1007/s11356-015-5817-4
    The main purpose of this work is to analyze the impact of environmental degradation proxied by CO2 emissions per capita along with some other explanatory variables namely energy use, trade, and human capital on economic growth in selected higher CO2 emissions economies namely China, the USA, India, and Japan. For empirical analysis, annual data over the period spanning between 1971 and 2013 are used. After using relevant and suitable tests for checking data properties, the panel fully modified ordinary least squares (FMOLS) method is employed as an analytical technique for parameter estimation. The panel group FMOLS results reveal that almost all variables are statistically significant, whereby test rejects the null hypotheses of non cointegration, demonstrating that all variables play an important role in affecting the economic growth role across countries. Where two regressors namely CO2 emissions and energy use show significantly negative impacts on economic growth, for trade and human capital, they tend to show the significantly positive impact on economic growth. However, for the individual analysis across countries, the panel estimate suggests that CO2 emissions have a significant positive relationship with economic growth for China, Japan, and the USA, while it is found significantly negative in case of India. The empirical findings of the study suggest that appropriate and prudent policies are required in order to control pollution emerging from areas other than liquefied fuel consumption. The ultimate impact of shrinking pollution will help in supporting sustainable economic growth and maturation as well as largely improve society welfare.
    Matched MeSH terms: Air Pollutants/analysis; Air Pollutants/economics*
  9. Masseran N, Razali AM, Ibrahim K, Latif MT
    Environ Monit Assess, 2016 Jan;188(1):65.
    PMID: 26718946 DOI: 10.1007/s10661-015-5070-9
    The air pollution index (API) is an important figure used for measuring the quality of air in the environment. The API is determined based on the highest average value of individual indices for all the variables which include sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and suspended particulate matter (PM10) at a particular hour. API values that exceed the limit of 100 units indicate an unhealthy status for the exposed environment. This study investigates the risk of occurrences of API values greater than 100 units for eight urban areas in Peninsular Malaysia for the period of January 2004 to December 2014. An extreme value model, known as the generalized Pareto distribution (GPD), has been fitted to the API values found. Based on the fitted model, return period for describing the occurrences of API exceeding 100 in the different cities has been computed as the indicator of risk. The results obtained indicated that most of the urban areas considered have a very small risk of occurrence of the unhealthy events, except for Kuala Lumpur, Malacca, and Klang. However, among these three cities, it is found that Klang has the highest risk. Based on all the results obtained, the air quality standard in urban areas of Peninsular Malaysia falls within healthy limits to human beings.
    Matched MeSH terms: Air Pollutants/analysis; Air Pollutants/chemistry
  10. Rene ER, Kar S, Krishnan J, Pakshirajan K, López ME, Murthy DV, et al.
    Bioresour Technol, 2015 Aug;190:529-35.
    PMID: 25827361 DOI: 10.1016/j.biortech.2015.03.049
    The performance of a compost biofilter inoculated with mixed microbial consortium was optimized for treating a gas-phase mixture of benzene and toluene. The biofilter was acclimated to these VOCs for a period of ∼18d. The effects of concentration and flow rate on the removal efficiency (RE) and elimination capacity (EC) were investigated by varying the inlet concentration of benzene (0.12-0.95g/m(3)), toluene (0.14-1.48g/m(3)) and gas-flow rate (0.024-0.072m(3)/h). At comparable loading rates, benzene removal in the mixture was reduced in the range of 6.6-41% in comparison with the individual benzene degradation. Toluene removal in mixture was even more affected as observed from the reductions in REs, ranging from 18.4% to 76%. The results were statistically interpreted by performing an analysis of variance (ANOVA) to elucidate the main and interaction effects.
    Matched MeSH terms: Air Pollutants/isolation & purification*; Air Pollutants/chemistry
  11. Hashim JH, Hashim Z, Omar A, Shamsudin SB
    Asia Pac J Public Health, 2000;12(2):65-70.
    PMID: 11836921
    The objective of this article is to study the influence of exposure and socio-economic variables on the blood lead level of Malaysian school children. Data on respirable lead and blood lead of 346 school children were obtained from Kuala Lumpur (urban), Kemaman (semi-urban) and Setiu (rural). Respirable lead and blood lead were highest for Kuala Lumpur (95 ng/m3 and 5.26 micrograms/dL) followed by Kemaman (27 ng/m3 and 2.81 micrograms/dL) and Setiu (15 ng/m3 and 2.49 micrograms/dL), and the differences were statistically significant. The percentage of school children with excessive blood lead of 10 micrograms/dL or greater was 6.36% overall, and highest for Kuala Lumpur (11.73%). Regression analyses show that urban children are at higher risk of exhibiting excessive blood lead levels. Kuala Lumpur's school children have a 25 times greater risk of having excessive blood lead levels when compared to Kemaman's and Setiu's school children. Respirable and blood lead were correlated (r = 0.999, p = 0.021). Urban school children acquire higher blood lead levels than their rural and semi-urban counterparts, even after controlling for age, sex, parents' education and income levels. In conclusion, it is time that lead in the Malaysian environment and population be monitored closely, especially its temporal and spatial variability. Only then can a comprehensive preventive strategy be implemented.
    Matched MeSH terms: Air Pollutants/adverse effects; Air Pollutants/blood*
  12. Zhou F, Cui J, Zhou J, Yang J, Li Y, Leng Q, et al.
    Sci Total Environ, 2018 Aug 15;633:776-784.
    PMID: 29602116 DOI: 10.1016/j.scitotenv.2018.03.217
    Atmospheric deposition nitrogen (ADN) increases the N content in soil and subsequently impacts microbial activity of soil. However, the effects of ADN on paddy soil microbial activity have not been well characterized. In this study, we studied how red paddy soil microbial activity responses to different contents of ADN through a 10-months ADN simulation on well managed pot experiments. Results showed that all tested contents of ADN fluxes (27, 55, and 82kgNha-1 when its ratio of NH4+/NO3--N (RN) was 2:1) enhanced the soil enzyme activity and microbial biomass carbon and nitrogen and 27kgNha-1 ADN had maximum effects while comparing with the fertilizer treatment. Generally, increasing of both ADN flux and RN (1:2, 1:1 and 2:1 with the ADN flux of 55kgNha-1) had similar reduced effects on microbial activity. Furthermore, both ADN flux and RN significantly reduced soil bacterial alpha diversity (p<0.05) and altered bacterial community structure (e.g., the relative abundances of genera Dyella and Rhodoblastus affiliated to Proteobacteria increased). Redundancy analysis demonstrated that ADN flux and RN were the main drivers in shaping paddy soil bacteria community. Overall, the results have indicated that increasing ADN flux and ammonium reduced soil microbial activity and changed the soil bacterial community. The finding highlights how paddy soil microbial community response to ADN and provides information for N management in paddy soil.
    Matched MeSH terms: Air Pollutants/analysis*; Air Pollutants/toxicity
  13. Plusquin M, Guida F, Polidoro S, Vermeulen R, Raaschou-Nielsen O, Campanella G, et al.
    Environ Int, 2017 11;108:127-136.
    PMID: 28843141 DOI: 10.1016/j.envint.2017.08.006
    Long-term exposure to air pollution has been associated with several adverse health effects including cardiovascular, respiratory diseases and cancers. However, underlying molecular alterations remain to be further investigated. The aim of this study is to investigate the effects of long-term exposure to air pollutants on (a) average DNA methylation at functional regions and, (b) individual differentially methylated CpG sites. An assumption is that omic measurements, including the methylome, are more sensitive to low doses than hard health outcomes. This study included blood-derived DNA methylation (Illumina-HM450 methylation) for 454 Italian and 159 Dutch participants from the European Prospective Investigation into Cancer and Nutrition (EPIC). Long-term air pollution exposure levels, including NO2, NOx, PM2.5, PMcoarse, PM10, PM2.5 absorbance (soot) were estimated using models developed within the ESCAPE project, and back-extrapolated to the time of sampling when possible. We meta-analysed the associations between the air pollutants and global DNA methylation, methylation in functional regions and epigenome-wide methylation. CpG sites found differentially methylated with air pollution were further investigated for functional interpretation in an independent population (EnviroGenoMarkers project), where (N=613) participants had both methylation and gene expression data available. Exposure to NO2 was associated with a significant global somatic hypomethylation (p-value=0.014). Hypomethylation of CpG island's shores and shelves and gene bodies was significantly associated with higher exposures to NO2 and NOx. Meta-analysing the epigenome-wide findings of the 2 cohorts did not show genome-wide significant associations at single CpG site level. However, several significant CpG were found if the analyses were separated by countries. By regressing gene expression levels against methylation levels of the exposure-related CpG sites, we identified several significant CpG-transcript pairs and highlighted 5 enriched pathways for NO2 and 9 for NOx mainly related to the immune system and its regulation. Our findings support results on global hypomethylation associated with air pollution, and suggest that the shores and shelves of CpG islands and gene bodies are mostly affected by higher exposure to NO2 and NOx. Functional differences in the immune system were suggested by transcriptome analyses.
    Matched MeSH terms: Air Pollutants/analysis; Air Pollutants/pharmacology*
  14. Nor Mohd Razif Noraini, Leman, A.M., Ahmad Sayuti Zainal Abidin
    MyJurnal
    A preliminary study has been conducted in a new constructed 8 stories building (2 level of Hostels facility, 3 level of Training Room, 2 Level of Offices and 1 level of Exhibition Halls and Rooms) in Bandar Baru Bangi, Selangor. The Hostels facility is a floor tile and furnished with build in locker and use split air conditioning system while the Training Room and Exhibition Rooms used floor tile. The Offices and Exhibition Hall are carpeted furnished. All these spaces were using centralized air conditioning systems. A pre-commissioning assessment on 5 chemical parameters of indoor air pollutants such Total Volatile Organic Compounds (TVOC), Formaldehyde, Respirable Particulates (PM!
    Matched MeSH terms: Air Pollutants
  15. Leman, A.M., Amir Khalid, Dafit Feriyanto, Abdullah, N.H., Abdullah, A.A., Mamat, R.
    MyJurnal
    In this research, the biodiesel from WCO is used in order to reduce the exhaust emission and to investigate the
    community perception regarding to the human health. Biodiesel production is conducted using trans-esterification
    process with holding time of 2 hours, temperature of 60 oC and conventional frequency of 20 kHz and then followed
    by washing process with holding time of 1 hours, temperature of 50 oC and the frequency of 5 kHz. Biodiesel can
    reduce exhaust emission of NOx up to 55%, NO gas up to 57%, increase CO gas up to 25% and increase CO2 gas up
    to 43.18% as compared to diesel fuel. In addition, biodiesel is achieve good responds from 35 respondents about the
    biodiesel importance.
    Matched MeSH terms: Air Pollutants
  16. Anwar A, Liew J, Othman M, Latif M
    Sains Malaysiana, 2010;39:169-174.
    Biomass burning is one of the main sources of air pollution in South East Asia, predominantly during the dry period between June and October each year. Sumatra and Kalimantan, Indonesia, have been identified as the regions connected to biomass burning due to their involvement in agricultural activities. In Sumatra, the Province of Riau has always been found to have had the highest number of hotspots during haze episodes. This study aims to determine the concentration of five major pollutants (PM10, SO2, NO2, CO and O3) in Riau, Indonesia, for 2006 and 2007. It will also correlate the level of air pollutants to the number of hotspots recorded, using the hotspot information system introduced by the Malaysian Centre for Remote Sensing (MACRES). Overall, the concentration of air pollutants recorded was found to increase with the number of hotspots. Nevertheless, only the concentration of PM10 during a haze episode is significantly different when compared to its concentration in non-haze conditions. In fact, in August 2006, when the highest number of hotspots was recorded the concentration of PM10 was found to increase by more than 20% from its normal concentration. The dispersion pattern, as simulated by the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), showed that the distribution of PM10 was greatly influenced by the wind direction. Furthermore, the particles had the capacity to reach the Peninsular Malaysia within 42 hours of emission from the point sources as a consequence of the South West monsoon.
    Matched MeSH terms: Air Pollutants
  17. Ling OHL, Siti Nur Afiqah Mohamed Musthafa, Abdul Rauf Abdul Rasam
    Sains Malaysiana, 2014;43:1405-1414.
    Environmental health in general is referring to the aspect of concern on healthy environment, and the interrelations between environment and human health. Due to the urbanization, urban development is changing the natural environment into a man-made environment. Along with the process, level of environmental quality and human health are decreased. Air quality as reference shows that urban ambient air is more polluted than rural. Due to high density of human population and their activities in urban areas, it produces air pollutants with higher rate as compared to less-developed areas. Air pollutants contribute to various health problems. People suffering from respiratory diseases are the most likely to be affected by air pollution. This paper aimed to examine the rate of respiratory infection among residents in an urban growth corridor (Petaling Jaya-Shah Alam-Klang) and the relationship with the urban land uses, traffic volume and air quality. There were four major types of data used in this study i.e., respiratory infection of the respondents, air quality, land use and traffic volume. A health questionnaire survey was carried out besides the secondary data collection from the various government departments. Relationship analysis was performed between respiratory health and the urban factors (air quality, traffic volume and land uses). The study found out that the relationship between the respiratory health and the urban factors is different in city-wide land use and traffic factors, as compared to the localised air quality and land use factors. To conclude, the urban factors are potentially affecting the respiratory health.
    Matched MeSH terms: Air Pollutants
  18. Adelin Anwar, Liew J, Mohd Talib Latif, Mohamed Rozali Othman
    Sains Malaysiana, 2010;39:169-174.
    Biomass burning is one of the main sources of air pollution in South East Asia, predominantly during the dry period between June and October each year. Sumatra and Kalimantan, Indonesia, have been identified as the regions connected to biomass burning due to their involvement in agricultural activities. In Sumatra, the Province of Riau has always been found to have had the highest number of hotspots during haze episodes. This study aims to determine the concentration of five major pollutants (PM10, SO2, NO2, CO and O3) in Riau, Indonesia, for 2006 and 2007. It will also correlate the level of air pollutants to the number of hotspots recorded, using the hotspot information system introduced by the Malaysian Centre for Remote Sensing (MACRES). Overall, the concentration of air pollutants recorded was found to increase with the number of hotspots. Nevertheless, only the concentration of PM10 during a haze episode is significantly different when compared to its concentration in non-haze conditions. In fact, in August 2006, when the highest number of hotspots was recorded the concentration of PM10 was found to increase by more than 20% from its normal concentration. The dispersion pattern, as simulated by the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), showed that the distribution of PM10 was greatly influenced by the wind direction. Furthermore, the particles had the capacity to reach the Peninsular Malaysia within 42 hours of emission from the point sources as a consequence of the South West monsoon.
    Matched MeSH terms: Air Pollutants
  19. Ku Yusof KMK, Ismail SS, Azid A, Sani MSA, Isa NM, Mohamat Zawawi MZ
    Data Brief, 2020 Apr;29:105210.
    PMID: 32071985 DOI: 10.1016/j.dib.2020.105210
    This paper provides detail on sequence analysis of hazy days based on eight monitoring stations from three states (Kelantan, Terengganu and Pahang) in the eastern region of Peninsular Malaysia. The dataset comprises of 1502 daily mean hazy days that had been measured for a decade. The meteorology data namely wind speed, wind direction, air temperature, relative humidity and particulate matter (PM10) were used to comprehend the variability, and the relationship existed amongst variables. The final dataset consists of a summary descriptive analysis and a boxplot, where all five variables were involved, including the minimum, maximum, mean, 1st quartile, median, 3rd quartile and standard deviation are presented. Apart from descriptive analysis, the normality test and histogram were performed as well.
    Matched MeSH terms: Air Pollutants
  20. Norlen Mohamed, Lokman Hakim Sulaiman, Thahirahtul Asma Zakaria, Anis Salwa Kamarudin, Daud Abdul Rahim
    Int J Public Health Res, 2016;6(1):685-694.
    MyJurnal
    Introduction During haze, at what level should Air Pollutant Index (API) showed, public
    or private school be closed is not without controversy and is very much
    debated. Therefore, the aim of this paper is to objectively quantify the
    potential inhaled dose of PM10 associated with exposure at school and home
    microenvironments during haze. The result of the health risk assessment will
    be used to propose the API level for closing the school during haze episode.

    Methods A hypothetical haze exposure scenario was created using the breakpoints of
    PM10 concentration for calculation of API and respective inhaled dose during
    haze. To determine the potential inhaled dose, we have considered many
    factors that include time spent for specific physical intensity at school and
    home microenvironments, age-specific and physical intensity-specific
    inhalation rate (m3/min), and the indoor/outdoor ratio of PM10. To calculate
    risk quotient (RQ), the inhaled dose was compared with the health reference
    dose computed based on the concentration of PM10 in the Malaysian
    Ambient Air Quality Standard.

    Results When considering the specific exposure at each microenvironment (school
    and home), the potential inhaled dose of PM10 was substantially lower when
    school is closed for both primary and secondary school. The calculated risk
    quotient (RQ) indicates that primary school children are likely to be affected
    at slightly lower PM10 concentration (equivalent to API of 197) as compared
    to secondary school children. Short duration of high physical activity
    intensity during school breaks has contributed to a large proportion of inhaled
    dose among school children indicating the important to avoid physical
    activities during haze.

    Conclusion Based on the assessment, taking into account the uncertainty of risk
    assessment methodology, we proposed school to be closed when API reach
    190 for both primary and secondary schools. These findings and
    recommendations are only valid for naturally ventilated school and applicable
    in the context of the current API calculation system and the existing
    Recommended Air Quality Guideline values in Malaysia.
    Matched MeSH terms: Air Pollutants
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