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Fulltext Evaluation of the 2013 Southeast Asian Haze on Solar Generation Performance

Maghami M, Hizam H, Gomes C, Hajighorbani S, Rezaei N

PLoS One, 2015;10(8):e0135118.
PMID: 26275303 DOI: 10.1371/journal.pone.0135118

Pollution in Southeast Asia is a major public energy problem and the cause of energy losses. A significant problem with respect to this type of pollution is that it decreases energy yield. In this study, two types of photovoltaic (PV) solar arrays were used to evaluate the effect of air pollution. The performance of two types of solar arrays were analysed in this research, namely, two units of a 1 kWp tracking flat photovoltaic (TFP) and two units of a 1 kWp fixed flat photovoltaic arrays (FFP). Data analysis was conducted on 2,190 samples at 30 min intervals from 01st June 2013, when both arrays were washed, until 30th June 2013. The performance was evaluated by using environmental data (irradiation, temperature, dust thickness, and air pollution index), power output, and energy yield. Multiple regression models were predicted in view of the environmental data and PV array output. Results showed that the fixed flat system was more affected by air pollution than the tracking flat plate. The contribution of this work is that it considers two types of photovoltaic arrays under the Southeast Asian pollution 2013.

Matched MeSH terms: Air Pollution*
Current advances and future prospects of in-situ desulfurization processes in oxy-fuel combustion reactors

Go ES, Ling JLJ, Solanki BS, Ahn H, Show PL, Lee SH

Environ Res, 2024 Dec 15;263(Pt 1):119982.
PMID: 39270960 DOI: 10.1016/j.envres.2024.119982

Oxy-fuel circulating fluidized bed combustion is known as one of the most potent fuel combustion technologies that capture ultra-low greenhouse gases and pollutant emissions. While many investigations have been conducted for carbon capturing, the associated in-situ desulfurization process using calcium-based sorbents should also be underlined. This paper critically reviews the effects of changes in the operating environment on in-situ desulfurization processes compared to conventional air combustion. A comprehensive understanding of the process, encompassing hydrodynamic, physical and chemical aspects can be a guideline for designing the oxy-fuel combustion process with effective sulfur removal, potentially eliminating the need of a flue gas desulfurization unit. Results from thermogravimetric analyzers and morphological changes of calcium-based materials were presented to offer an insight into the sulfation mechanisms involved in the oxy-fuel circulating fluidized beds. Recently findings suggested that in-situ direct desulfurization is influenced not only by the desulfurization kinetics but also by the fluidization characteristics of calcium-based materials. Therefore, a complex reaction analysis that incorporated oxy-combustion reactions, computational fluid dynamics modeling, in-situ desulfurization reaction models and particle behavior can provide a thorough understanding of desulfurization processes across the reactor. Meanwhile, machine learning as a robust tool to predict desulfurization efficiency and improve operational flexibility should be applied with consideration of environmental improvement and economic feasibility.

Matched MeSH terms: Air Pollution/prevention & control
Developing a hierarchical framework for assessing the strategic effectiveness of sustainable waste management in the Somaliland construction industry

Negash YT, Hassan AM, Tseng ML, Ali MH, Lim MK

Environ Sci Pollut Res Int, 2023 May;30(25):67303-67325.
PMID: 37103710 DOI: 10.1007/s11356-023-27060-8

This study contributes to develop a hierarchical framework for assessing the strategic effectiveness of waste management in the construction industry. This study identifies a valid set of strategic effectiveness attributes of sustainable waste management (SWM) in construction. Prior studies have neglected to develop a strategic effectiveness assessment framework for SWM to identify reduce, reuse, and recycle policy initiatives that ensure waste minimization and resource recovery programs. This study utilizes the fuzzy Delphi method to screen out nonessential attributes in qualitative information. This study initially proposes a set of 75 criteria; after two rounds of assessment, consensus regarding 28 criteria is achieved among experts, and the 28 criteria are validated. Fuzzy interpretive structural modeling divides the attributes into various elements. The modeling constructs a six-level model that depicts the interrelationships among the 28 validated criteria as a hierarchical framework, and it finds and ranks the optimal drivers for practical improvement. This study integrates the best-worst method to measure the weights of different criteria in the hierarchical strategic effectiveness framework. The findings reveal that waste management operational strategy, construction site waste management performance, and the mutual coordination level are the top aspects for assessing strategic effectiveness in the hierarchical framework. In practice, the waste reduction rate, the recycling rate, water and land usage, the reuse rate, and noise and air pollution levels are identified to assist policymakers in evaluation. The theoretical and managerial implications are discussed.

Matched MeSH terms: Air Pollution*
Importance of green roof criteria for residential and governmental buildings: a multi-criteria decision analysis

Gohari A, Gohari A, Ahmad AB

Environ Sci Pollut Res Int, 2023 Jan;30(2):3707-3725.
PMID: 35953748 DOI: 10.1007/s11356-022-22472-4

Megacities recently are experiencing a shortage of green spaces basically due to the rapid growth of urbanization and increasing demand for different building types. Consideration of sustainable urban development is essential since the expansion of city facilities should be in line with social, economic, and environmental aspects. In this regard, green roof technology has been recommended as an effective solution for the growth of green spaces per capita and improving sustainability means of urban developments due to its diverse advantages. This study thus aimed at prioritizing sustainability indicators and relative sub-criteria of adopting green roof technology for residential and governmental buildings in the city of Mashhad, Iran, which has a dry climate. For this purpose, thirteen sub-criteria, which are extracted from the existing literature, are classified into three main sustainability indicators (environmental, economic, and social). Also, the best-worth method (BWM) as a multi-criteria decision-making technique was implemented to prioritize indicators and sub-criteria by analyzing the expert's opinion. The results indicated that respective economic and environmental indicators attract the highest priority in residential and governmental buildings. Additionally, the most important sub-criteria in environmental, economic, and social groups are air quality, roof longevity, and public health in both building types, respectively. However, when all criteria were considered, the respective highest priorities belong to roof longevity and air quality in residential and governmental buildings, while biodiversity conservation is the least important one in both building types. The results of this research can be beneficial in other cities with similar economic and climate conditions.

Matched MeSH terms: Air Pollution*
Bibliometric analysis and literature review of occupant thermal comfort in naturally ventilated buildings (1995-2021)

Abuhussain MA, Alotaibi BS, Suru IB, Dodo YA, Alshenaifi MA, Aliero MS

Environ Sci Pollut Res Int, 2024 Oct;31(46):56983-57001.
PMID: 38001292 DOI: 10.1007/s11356-023-31053-y

This paper presents the global research landscape and scientific progress on occupant thermal comfort in naturally ventilated buildings (OTC-NVB). Despite the growing interest in the area, comprehensive papers on the current status and future developments on the topic are currently lacking. Hence, the publication trends, bibliometric analysis, and systematic literature review of the published documents on OTC-NVB were examined. The search query "Thermal Comfort" AND "Natural Ventilation" AND "Buildings" was designed and executed to recover related documents on the topic from the Elsevier Scopus database. Results showed that 976 documents (comprising articles, conference papers, reviews, etc.) were published on the topic from 1995 to 2021. Further analysis showed that 97.34% of the publications were published in the English language. Richard J.de Dear (University of Sydney, Australia) is the most prolific researcher on OTC-NVB research, while Energy and Buildings has the highest publications. Bibliometric analysis showed high publications, citations, keywords, and co-authorships among researchers, whereas the most occurrent keywords are ventilation, natural ventilation, thermal comfort, buildings, and air conditioning. Systematic literature review demonstrated that OTC-NVB research has progressed significantly from empirical to computer-based studies involving complex mathematical equations, programs, or software like artificial neural networks (ANN) and computational fluid dynamics (CFD). In general, OTC-NVB research findings indicate that physiological, social, and environmental factors considerably influence OTC in NVBs. Future studies will likely employ artificial intelligence or building performance simulation (BPS) tools to examine relationships between OTC and indoor air/environmental quality, human behavior, novel clothing, or building materials in NVBs.

Matched MeSH terms: Air Conditioning; Air Pollution, Indoor
The cloud over Sarawak

Nature, 1997 Sep 25;389(6649):315.
PMID: 9311758
Matched MeSH terms: Air Pollution*
Haze and health impacts in ASEAN countries: a systematic review

Ramakreshnan L, Aghamohammadi N, Fong CS, Bulgiba A, Zaki RA, Wong LP, et al.

Environ Sci Pollut Res Int, 2018 Jan;25(3):2096-2111.
PMID: 29209970 DOI: 10.1007/s11356-017-0860-y

Seasonal haze episodes and the associated inimical health impacts have become a regular crisis among the ASEAN countries. Even though many emerging experimental and epidemiological studies have documented the plausible health effects of the predominating toxic pollutants of haze, the consistency among the reported findings by these studies is poorly understood. By addressing such gap, this review aimed to critically highlight the evidence of physical and psychological health impacts of haze from the available literature in ASEAN countries. Systematic literature survey from six electronic databases across the environmental and medical disciplines was performed, and 20 peer-reviewed studies out of 384 retrieved articles were selected. The evidence pertaining to the health impacts of haze based on field survey, laboratory tests, modelling and time-series analysis were extracted for expert judgement. In specific, no generalization can be made on the reported physical symptoms as no specific symptoms recorded in all the reviewed studies except for throat discomfort. Consistent evidence was found for the increase in respiratory morbidity, especially for asthma, whilst the children and the elderly are deemed to be the vulnerable groups of the haze-induced respiratory ailments. A consensual conclusion on the association between the cardiovascular morbidity and haze is unfeasible as the available studies are scanty and geographically limited albeit of some reported increased cases. A number of modelling and simulation studies demonstrated elevating respiratory mortality rates due to seasonal haze exposures over the years. Besides, evidence on cancer risk is inconsistent where industrial and vehicular emissions are also expected to play more notable roles than mere haze exposure. There are insufficient regional studies to examine the association between the mental health and haze. Limited toxicological studies in ASEAN countries often impede a comprehensive understanding of the biological mechanism of haze-induced toxic pollutants on human physiology. Therefore, the lack of consistent evidence among the reported haze-induced health effects as highlighted in this review calls for more intensive longitudinal and toxicological studies with greater statistical power to disseminate more reliable and congruent findings to empower the institutional health planning among the ASEAN countries.

Matched MeSH terms: Air Pollutants/analysis*; Air Pollutants/toxicity
Pre- commissioning on indoor air quality: chemical parameters in new building

Nor Mohd Razif Noraini, Leman, A.M., Ahmad Sayuti Zainal Abidin

Journal of Occupational Safety and Health, 2011;8(2):1-10.
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 Conditioning; Air Pollutants; Air Pollution, Indoor
Characterization of rainwater chemical composition after a Southeast Asia haze event: insight of transboundary pollutant transport during the northeast monsoon

Nadzir MSM, Lin CY, Khan MF, Latif MT, Dominick D, Hamid HHA, et al.

Environ Sci Pollut Res Int, 2017 Jun;24(18):15278-15290.
PMID: 28500553 DOI: 10.1007/s11356-017-9131-1

Open biomass burning in Peninsula Malaysia, Sumatra, and parts of the Indochinese region is a major source of transboundary haze pollution in the Southeast Asia. To study the influence of haze on rainwater chemistry, a short-term investigation was carried out during the occurrence of a severe haze episode from March to April 2014. Rainwater samples were collected after a prolonged drought and analyzed for heavy metals and major ion concentrations using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. The chemical composition and morphology of the solid particulates suspended in rainwater were examined using a scanning electron microscope coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). The dataset was further interpreted using enrichment factors (EF), statistical analysis, and a back trajectory (BT) model to find the possible sources of the particulates and pollutants. The results show a drop in rainwater pH from near neutral (pH 6.54) to acidic (

Matched MeSH terms: Air Movements; Air Pollutants*
Impact of socioeconomic and meteorological factors on reservoirs' air quality: a case in the Three Gorges Reservoir of Chongqing (TGRC), China over a 10-year period

Peng Y, Zhou F, Cui J, Du K, Leng Q, Yang F, et al.

Environ Sci Pollut Res Int, 2017 Jul;24(19):16206-16219.
PMID: 28540543 DOI: 10.1007/s11356-017-9221-0

The Three Gorges Dam's construction and industrial transfer have resulted in a new air pollution pattern with the potential to threaten the reservoir eco-environment. To assess the impact of socioeconomic factors on the pattern of air quality vairation and economical risks, concentrations of SO2, NO2, and PM10, industry genres, and meteorological conditions were selected in the Three Gorges Reservoir of Chongqing (TGRC) during 2006-2015. Results showed that air quality had improved to some extent, but atmospheric NO2 showed an increased trend during 2011-2015. Spatially, higher atmospheric NO2 extended to the surrounding area. The primary industry, especially for agriculture, had shown to be responsible for the remarkable increase of atmospheric NO2 (p air pollutant reductions, but construction industries had inhibited the improvement of regional air quality. In the tertiary industry, the cargo industry at ports had significantly decreased atmospheric NO2 as a result of eliminating the obsoleted small ships. Contrarily, the highway transportation had brought more air pollutants. The relative humidity was shown to be the main meteorological factor, which had an extremely remarkable relation with atmospheric SO2 (p air quality improvement difficult, and atmospheric SO2, NO2, and PM10 deposition would aggravate regional soil and water acidification and reactivate heavy metal in soil and sediment, further to pose a high level of ecological risk in the TGRC and other countries with reservoirs in the world.

Matched MeSH terms: Air Pollutants; Air Pollution*
Fulltext Systematic study on the relationship between particulate matter and microbial counts in hospital operating rooms

Tan H, Wong KY, Nyakuma BB, Kamar HM, Chong WT, Wong SL, et al.

Environ Sci Pollut Res Int, 2022 Jan;29(5):6710-6721.
PMID: 34458973 DOI: 10.1007/s11356-021-16171-9

In this study, a systematic procedure for establishing the relationship between particulate matter (PM) and microbial counts in four operating rooms (ORs) was developed. The ORs are located in a private hospital on the western coast of Peninsular Malaysia. The objective of developing the systematic procedure is to ensure that the correlation between the PMs and microbial counts are valid. Each of the procedures is conducted based on the ISO, IEST, and NEBB standards. The procedures involved verifying the operating parameters are air change rate, room differential pressure, relative humidity, and air temperature. Upon verifying that the OR parameters are in the recommended operating range, the measurements of the PMs and sampling of the microbes were conducted. The TSI 9510-02 particle counter was used to measure three different sizes of PMs: PM 0.5, PM 5, and PM 10. The MAS-100ECO air sampler was used to quantify the microbial counts. The present study confirms that PM 0.5 does not have an apparent positive correlation with the microbial count. However, the evident correlation of 7% and 15% were identified for both PM 5 and PM 10, respectively. Therefore, it is suggested that frequent monitoring of both PM 5 and PM 10 should be practised in an OR before each surgical procedure. This correlation approach could provide an instantaneous estimation of the microbial counts present in the OR.

Matched MeSH terms: Air Microbiology; Air Pollutants*
Evaluating the properties that affect the quality of the charcoal product, determining the limits of toxic emissions during combustion, and studying their impact on human health

Alzahrani A, Hassan MA, Alsubaie S

Environ Geochem Health, 2024 Jul 09;46(8):295.
PMID: 38980526 DOI: 10.1007/s10653-024-02065-5

This research focuses on examining the potential impact of charcoal briquettes and lumps on human health due to the emissions they release, and verifying their quality standards. Quality assessment was conducted using a device capable of measuring toxic gases to identify contaminants from various sources such as biomass, synthetic resins, coal, metals, and mineral matter. Toxicity assessments were carried out on five types of briquettes and two varieties of lump charcoal. All charcoal samples were subjected to elemental analysis (SEM/EDAX), including the examination of Ca, Al, Cr, V, Cu, Fe, S, Sr, Si, Ba, Pb, P, Mn, Rb, K, Ti, and Zn. The results showed that burning lump charcoal had toxicity indexes ranging from 2.5 to 5, primarily due to NOx emissions. Briquettes, on the other hand, exhibited higher toxicity indices between 3.5 and 6.0, with CO2 being the main contributor to toxicity. The average 24-h CO content of all charcoal samples exceeded the World Health Organization's 24-h Air Quality Guideline of 6.34 ppm, with a measurement of 37 ppm. The data indicates that most of the products tested did not meet the prevailing quality standard (EN 1860-2:2005 (E) in Appliances, solid fuels and firelighters for barbecuing-Part 2: Barbecue charcoal and barbecue charcoal briquettes-Requirements and test method, 2005), which specifies a maximum of 1% contaminants, with some products containing as much as 21% impurities. The SEM analysis revealed irregularly shaped grains with an uneven distribution of particles, and the average particle size distribution is quite broad at 5 μm. Malaysia Charcoal had the highest calorific value at 32.80 MJ/Kg, with the value being influenced by the fixed carbon content-higher carbon content resulting in a higher calorific value.

Matched MeSH terms: Air Pollutants/analysis; Air Pollutants/toxicity
Fulltext Indoor radon concentration in Kinta Valley

Ismail Sulaiman, Khairuddin Mohamad Kontol, Faizal Azrin Abdul Razalim, Azman Jaafar

Jurnal Sains Nuklear Malaysia, 2017;29(1):37-44.
MyJurnal

The objective of this study was to measure indoor radon concentrations in the expected high risk area around Ipoh in Kinta Valley, Perak. The area was chosen based on its own special characteristics. The measurements were carried out by means of long term exposure (3 months) using CR-39 solid state nuclear track detector. The mean indoor radon concentration in Ipoh was 45 Bq/m3 which is equivalent to effective dose of 1.1 mSv/y. This value was higher compared to low or normal area in Bangi, Selangor but comparable to the world average value reported by UNSCEAR. The maximum value of indoor radon concentration measured was 87 Bq/m3.

Matched MeSH terms: Air Pollutants, Radioactive
An Integrated Source Apportionment Methodology and Its Application over the Yangtze River Delta Region, China

Li L, An J, Zhou M, Qiao L, Zhu S, Yan R, et al.

Environ Sci Technol, 2018 Dec 18;52(24):14216-14227.
PMID: 30288976 DOI: 10.1021/acs.est.8b01211

An integrated source apportionment methodology is developed by amalgamating the receptor-oriented model (ROM) and source-oriented numerical simulations (SOM) together to eliminate the weaknesses of individual SA methods. This approach attempts to apportion and dissect the PM2.5 sources in the Yangtze River Delta region during winter. First, three ROM models (CMB, PMF, ME2) are applied and compared for the preliminary SA results, with information from PM2.5 sampling and lab analysis during the winter seasons. The detailed source category contribution of SOM to PM2.5 is further simulated using the WRF-CAMx model. The two pieces of information from both ROM and SOM are then stitched together to give a comprehensive information on the PM2.5 sources over the region. With the integrated approach, the detailed contributing sources of the ambient PM2.5 at different receptors including rural and urban, coastal and in-land, northern and southern receptors are analyzed. The results are compared with previous data and shows good agreement. This integrative approach is more comprehensive and is able to produce a more profound and detailed understanding between the sources and receptors, compared with single models.

Matched MeSH terms: Air Pollutants
Fulltext Mass and elemental concentrations of airborne particles at Kuala Lumpur site in 2000 to 2006

Mohd Suhaimi Hamzah, Shamsiah Abdul Rahman, Abdul Khalik Wood

Journal of Nuclear and Related Technologies, 2008;2008(2):27-34.
MyJurnal

Atmospheric Pollution due to airborne particle is a major concern to many cities in the Southeast Asian region, including Kuala Lumpur. Within the last six years air particulate samples have been collected from a site in Kuala Lumpur and measured for their PM10, PM2.5 and elemental concentrations. The results showed that the daily PM10 (

Matched MeSH terms: Air Pollutants
Fulltext The COVID-19 impact on air condition usage: a shift towards residential energy saving

Aliero MS, Pasha MF, Toosi AN, Ghani I

Environ Sci Pollut Res Int, 2022 Dec;29(57):85727-85741.
PMID: 35001275 DOI: 10.1007/s11356-021-17862-z

The enforcement of the Movement Control Order to curtail the spread of COVID-19 has affected home energy consumption, especially HVAC systems. Occupancy detection and estimation have been recognized as key contributors to improving building energy efficiency. Several solutions have been proposed for the past decade to improve the precision performance of occupancy detection and estimation in the building. Environmental sensing is one of the practical solutions to detect and estimate occupants in the building during uncertain behavior. However, the literature reveals that the performance of environmental sensing is relatively poor due to the poor quality of the training dataset used in the model. This study proposed a smart sensing framework that combined camera-based and environmental sensing approaches using supervised learning to gather standard and robust datasets related to indoor occupancy that can be used for cross-validation of different machine learning algorithms in formal research. The proposed solution is tested in the living room with a prototype system integrated with various sensors using a random forest regressor, although other techniques could be easily integrated within the proposed framework. The primary implication of this study is to predict the room occupation through the use of sensors providing inputs into a model to lower energy consumption. The results indicate that the proposed solution can obtain data, process, and predict occupant presence and number with 99.3% accuracy. Additionally, to demonstrate the impact of occupant number in energy saving, one room with two zones is modeled each zone with air condition with different thermostat controller. The first zone uses IoFClime and the second zone uses modified IoFClime using a design-builder. The simulation is conducted using EnergyPlus software with the random simulation of 10 occupants and local climate data under three scenarios. The Fanger model's thermal comfort analysis shows that up to 50% and 25% energy can be saved under the first and third scenarios.

Matched MeSH terms: Air Conditioning
Long term assessment of air quality from a background station on the Malaysian Peninsula

Latif MT, Dominick D, Ahamad F, Khan MF, Juneng L, Hamzah FM, et al.

Sci Total Environ, 2014 Jun 1;482-483:336-48.
PMID: 24662202 DOI: 10.1016/j.scitotenv.2014.02.132

Rural background stations provide insight into seasonal variations in pollutant concentrations and allow for comparisons to be made with stations closer to anthropogenic emissions. In Malaysia, the designated background station is located in Jerantut, Pahang. A fifteen-year data set focusing on ten major air pollutants and four meteorological variables from this station were analysed. Diurnal, monthly and yearly pollutant concentrations were derived from hourly continuous monitoring data. Statistical methods employed included principal component regression (PCR) and sensitivity analysis. Although only one of the yearly concentrations of the pollutants studied exceeded national and World Health Organisation (WHO) guideline standards, namely PM10, seven of the pollutants (NO, NO2, NOx, O3, PM10, THC and CH4) showed a positive upward trend over the 15-year period. High concentrations of PM10 were recorded during severe haze episodes in this region. Whilst, monthly concentrations of most air pollutants, such as: PM10, O3, NOx, NO2, CO and NmHC were recorded at higher concentrations between June and September, during the southwest monsoon. Such results correspond with the mid-range transport of pollutants from more urbanised and industrial areas. Diurnal patterns, rationed between major air pollutants and sensitivity analysis, indicate the influence of local traffic emissions on air quality at the Jerantut background station. Although the pollutant concentrations have not shown a rapid increase, an alternative background station will need to be assigned within the next decade if development projects in the surrounding area are not halted.

Matched MeSH terms: Air Pollutants/analysis*; Air Pollution/statistics & numerical data*
New generation sequencing: molecular approaches for the detection and monitoring of bioaerosols in an indoor environment: a systematic review

Onwusereaka CO, Jalaludin J, Oluchi SE, Poh Choo VC

Rev Environ Health, 2025 Mar 26;40(1):47-62.
PMID: 38214730 DOI: 10.1515/reveh-2023-0004

INTRODUCTION: The exposure of occupants to indoor air pollutants has increased in recent decades. The aim of this review is to discuss an overview of new approaches that are used to study fungal aerosols. Thus, this motivation was to compensate the gaps caused by the use of only traditional approaches in the study of fungal exposure.
CONTENT: The search involved various databases such as; Science Direct, PubMed, SAGE, Springer Link, EBCOHOST, MEDLINE, CINAHL, Cochrane library, Web of Science and Wiley Online Library. It was limited to full text research articles that reported the use of non-viable method in assessing bioaerosol, written in English Language, full text publications and published from year 2015-2022.
SUMMARY AND OUTLOOK: A total of 15 articles met the inclusion criteria and was included in this review. The use of next-generation sequencing, which is more commonly referred to as high-throughput sequencing (HTS) or molecular methods in microbial studies is based on the detection of genetic material of organisms present in a given sample. Applying these methods to different environments permitted the identification of the microorganisms present, and a better comprehension of the environmental impacts and ecological roles of microbial communities. Based on the reviewed articles, there is evidence that dust samples harbour a high diversity of human-associated bacteria and fungi. Molecular methods such as next generation sequencing are reliable tools for identifying and tracking the bacterial and fungal diversity in dust samples using 18S metagenomics approach.

Matched MeSH terms: Air Microbiology*; Air Pollutants/analysis
Fulltext Bacterial constituents of indoor air in a high throughput building in the tropics

Li TC, Ambu S, Mohandas K, Wah MJ, Sulaiman LH, Murgaiyah M

Trop Biomed, 2014 Sep;31(3):540-56.
PMID: 25382482 MyJurnal

Airborne bacteria are significant biotic constituents of bioaerosol. Bacteria at high concentrations in the air can compromise indoor air quality (IAQ) and result in many diseases. In tropical environments like Malaysia that extensively utilize air-conditioning systems, this is particularly significant due to continuous recirculation of indoor air and the potential implications for human health. Currently, there is a lack of knowledge regarding the impact of airborne bacteria on IAQ in Malaysia. This study was prompted by a need for reliable baseline data on airborne bacteria in the indoor environment of tropical equatorial Malaysia, that may be used as a reference for further investigations on the potential role played by airborne bacteria as an agent of disease in this region. It was further necessitated due to the threat of bioterrorism with the potentiality of release of exotic pathogenic microorganisms into indoor or outdoor air. Before scientists can detect the latter, a gauge of the common microorganisms in indoor (as well as outdoor) air needs to be ascertained, hence the expediency of this study. Bacterial counts from the broad-based and targeted study were generally in the order of 10(2) colony-forming units (CFU) per m(3) of air. The most prevalent airborne bacteria found in the broad-based study that encompassed all five levels of the building were Gram-positive cocci (67.73%), followed by Gram-positive rods (24.26%) and Gram-negative rods (7.10%). Gram-negative cocci were rarely detected (0.71%). Amongst the genera identified, Kytococcus sp., Micrococcus sp., Staphylococcus sp., Leifsonia sp., Bacillus sp. and Corynebacterium sp. predominated in indoor air. The most dominant bacterial species were Kytococcus sedentarius, Staphylococcus epidermidis and Micrococcus luteus. The opportunistic and nosocomial pathogen, Stenotrophomonas maltophilia was also discovered at a high percentage in the cafeteria. The bacteria isolated in this study have been increasingly documented to cause opportunistic infections in immuno-compromised patients, sometimes with fatal outcomes. Furthermore, some of them are becoming increasingly resistant to antibiotics. Hence, we propose that indoor reservoirs of these bacteria and their associated clinical and more subtle health effects, if any, be investigated further.

Matched MeSH terms: Air Microbiology*; Air Pollution, Indoor*
Estimation of aerosol optical depth at different wavelengths by multiple regression method

Tan F, Lim HS, Abdullah K, Holben B

Environ Sci Pollut Res Int, 2016 Feb;23(3):2735-48.
PMID: 26438373 DOI: 10.1007/s11356-015-5506-3

This study aims to investigate and establish a suitable model that can help to estimate aerosol optical depth (AOD) in order to monitor aerosol variations especially during non-retrieval time. The relationship between actual ground measurements (such as air pollution index, visibility, relative humidity, temperature, and pressure) and AOD obtained with a CIMEL sun photometer was determined through a series of statistical procedures to produce an AOD prediction model with reasonable accuracy. The AOD prediction model calibrated for each wavelength has a set of coefficients. The model was validated using a set of statistical tests. The validated model was then employed to calculate AOD at different wavelengths. The results show that the proposed model successfully predicted AOD at each studied wavelength ranging from 340 nm to 1020 nm. To illustrate the application of the model, the aerosol size determined using measure AOD data for Penang was compared with that determined using the model. This was done by examining the curvature in the ln [AOD]-ln [wavelength] plot. Consistency was obtained when it was concluded that Penang was dominated by fine mode aerosol in 2012 and 2013 using both measured and predicted AOD data. These results indicate that the proposed AOD prediction model using routine measurements as input is a promising tool for the regular monitoring of aerosol variation during non-retrieval time.

Matched MeSH terms: Air Pollutants/chemistry*; Air Pollution/analysis

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