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Fulltext Determination of chemical content of pm10 and tsp using SEM-EDAX

Masitah Alias, Zaini Hamzah

Journal of Nuclear and Related Technologies, 2007;2007(1):217-226.
MyJurnal

The growing concern over the workers safety and health has lead many factories and organizations do the air monitoring to ensure the airborne at their workplace is safe for the worker’s health and complying the Occupational Safety and Health Act 1994 (Act 514). In this study, the monitoring covers an indoor air quality and chemical exposure to the workers in one of the power plant repair shop. A few workers from different sections namely blasting, welding, grinding, fitting and maintenance area were chosen to assist in the personal monitoring for 8 hours measurement. PM10 were measured at a few sampling points to collect dusts for 24 hours duration. The samples were brought back to the laboratory for gravimetric and SEM-EDAX analysis. The results were certainly exceed the limit for air quality, and many elements were detected such as Fe, Ni, Al, Si, Ca, K, Ba, S, Cr, Zn and Cl. The present of these elements shows that exposure to these particulate matters is quite risky and some measure needs to be taken for remedial action.

Matched MeSH terms: Dust
Environmental hazards posed by mine dust, and monitoring method of mine dust pollution using remote sensing technologies: An overview

Yu H, Zahidi I

Sci Total Environ, 2023 Mar 15;864:161135.
PMID: 36566867 DOI: 10.1016/j.scitotenv.2022.161135

The over-exploitation of mineral resources has led to increasingly serious dust pollution in mines, resulting in a series of negative impacts on the environment, mine workers (occupational health) and nearby residents (public health). For the environment, mine dust pollution is considered a major threat on surface vegetation, landscapes, weather conditions and air quality, leading to serious environmental damage such as vegetation reduction and air pollution; for occupational health, mine dust from the mining process is also regarded as a major threat to mine workers' health, leading to occupational diseases such as pneumoconiosis and silicosis; for public health, the pollutants contained in mine dust may pollute surrounding rivers, farmlands and crops, which poses a serious risk to the domestic water and food security of nearby residents who are also susceptible to respiratory diseases from exposure to mine dust. Therefore, the second section of this paper combines literature research, statistical studies, and meta analysis to introduce the public mainly to the severity of mine dust pollution and its hazards to the environment, mine workers (occupational health), and residents (public health), as well as to present an outlook on the management of mine dust pollution. At the same time, in order to propose a method for monitoring mine dust pollution on a regional scale, based on the Dense Dark Vegetation (DDV) algorithm, the third section of this paper analysed the aerosol optical depth (AOD) change in Dexing City of China using the data of 2010, 2014, 2018 and 2021 from the NASA MCD19A2 Dataset to explore the mine dust pollution situation and the progress of pollution treatment in Dexing City from 2010 to 2021. As a discussion article, this paper aims to review the environmental and health risks caused by mine dust pollution, to remind the public to take mine dust pollution seriously, and to propose the use of remote sensing technologies to monitor mine dust pollution, providing suggestions for local governments as well as mines on mine dust monitoring measures.

Matched MeSH terms: Dust/analysis
A comprehensive review on pollution status and associated health risk assessment of human exposure to selected heavy metals in road dust across different cities of the world

Shahab A, Hui Z, Rad S, Xiao H, Siddique J, Huang LL, et al.

Environ Geochem Health, 2023 Mar;45(3):585-606.
PMID: 35347514 DOI: 10.1007/s10653-022-01255-3

In order to expound on the present situation and potential risk of road dust heavy metals in major cities, a total of 114 literatures mainly over the past two decades, involving more than 5000 sampling sites in 61 cities of 21 countries, were screened through the collection and analysis of research papers. The concentration, sources, distribution, health risk, sample collection, and analytical methods of heavy metal research on road dust in cities around the world are summarized. The results show that Cd, Zn, and Cu in many urban road dusts in the world are higher than the grade II of the Chinese maximum allowable concentration of potentially toxic elements in the soil. Geo-accumulation index values show that Pb > Cd > Zn > Cu had the highest contamination levels. Hazard index assessment indicates Pb and Cr had the highest potential health risk, especially for children in which ingestion was found as the main exposure pathway. Moreover, through comparative analysis, it is found that some pollutants are higher in developed and industrialized cities and transport (53%) followed by industrial emissions (35%) provide the major contributions to the sources of heavy metals.

Matched MeSH terms: Dust/analysis
Particle size and metals concentrations of dust from a paint manufacturing plant

Huang SL, Yin CY, Yap SY

J Hazard Mater, 2010 Feb 15;174(1-3):839-42.
PMID: 19836131 DOI: 10.1016/j.jhazmat.2009.09.129

In this study, the particle size distribution and concentration of metallic elements of solvent- and water-based paint dust from bulk dust collected from dust-collecting hoppers were determined. The mean particle size diameter over a 12-week sampling period was determined using a particle size analyzer. The metals composition and concentration of the dust were determined via acid digestion technique followed by concentration analysis using inductively coupled plasma. The volume weighted mean particle diameters were found to be 0.941+/-0.016 and 8.185+/-0.201 microm for solvent- and water-based paint dust, respectively. The mean concentrations of metals in solvent-based paint dust were found to be 100+/-20.00 microg/g (arsenic), 1550+/-550.00 microg/g (copper), 15,680+/-11,780.00 microg/g (lead) and 30,460+/-10,580.00 microg/g (zinc) while the mean concentrations of metals in water-based paint dust were found to be 20.65+/-6.11 microg/g (arsenic), 9.14+/-14.65 microg/g (copper), 57.46+/-22.42 microg/g (lead) and 1660+/-1260 microg/g (zinc). Both paint dust types could be considered as hazardous since almost all of the dust particles were smaller than 10 microm. Particular emphasis on containment of solvent-based paint dust particles should be given since it was shown that they were very fine in size (<1 microm) and had high lead and zinc concentrations.

Matched MeSH terms: Dust*; Industry*
Fulltext Evaluation of the modified-ceylon copra kiln for accelerated production of ball copra

Marikkar, J.M.N., Banu, M.K.I., Yalegama, C.

International Food Research Journal, 2009;16(2):175-181.
MyJurnal

This study attempted to investigate the effect of kiln drying on the rate of formation of ball copra. Three samples containing fifty partially dried-coconuts were placed as a single layer in three compartmentalized blocks namely, Front: Blok-1, Middle: Block-2, and Rear: Block-3 in the copra bed of the modified-Ceylon copra kiln. From each of the three blocks, thirty coconuts were selected randomly for labeling and their fresh weights were recorded. The samples were subjected to intermittent drying in the kiln by thirty five firing cycles using charcoal dust as the fuel source. The temperature distribution pattern of the three blocks during the first six firing was monitored at three hourly intervals. The weight losses of individual coconuts in each block were measured after the completion of each firing. The results showed that, there was a significant (p

Matched MeSH terms: Dust
Radiation dose assessment at amang processing plants in Malaysia

Omar M, Sulaiman I, Hassan A, Wood AK

Radiat Prot Dosimetry, 2007;124(4):400-6.
PMID: 17510205

Measurements of external radiation level, radon/thoron daughters concentrations in air and uranium/thorium concentrations in airborne mineral dust at 16 amang plants in Malaysia were carried out for three consecutive months to assess radiation dose to workers. Estimated occupational dose was within the range of 1.7-10.9 mSv y(-1). The mean total dose at the amang plants was 4.1 mSv y(-1). Overall, it was found that the major dose contribution of 80% came from external radiation. Radon/thoron daughters and airborne mineral dust contributed to only 11 and 9% of the total dose, respectively.

Matched MeSH terms: Dust/analysis
Fulltext House dust mite fauna in the Klang Valley, Malaysia

Mariana A, Ho TM, Sofian-Azirun M, Wong AL

Southeast Asian J. Trop. Med. Public Health, 2000 Dec;31(4):712-21.
PMID: 11414418

Allergy to house dust mites (HDM) is an important cause of asthma and rhinitis in Malaysia. This study was carried out to evaluate the dust mite fauna in the Klang Valley. Dust samples were collected from 20 houses from March 1994 to February 1995. Thirty-three dust samples from mattresses were examined monthly for the occurrence of HDM. A total of 22 species in 9 families of HDM was identified. The most common and densely populated species was Blomia tropicalis with an average density of 8,934 mites/g of dust. Dermatophagoides pteronyssinus was the next in abundance, followed by Malayoglyphus intermedius. All houses surveyed were found to be infested with HDM and every house had at least 6 species of HDM. B. tropicalis and D. pteronyssinus were found in all mattresses. HDM in the Klang Valley were found to be highly prevalent and present in high densities. In this study, counts of D. pteronyssinus was found to exceed the proposed exposure threshold of 500 mites/g dust, for triggering acute asthma. Although counts of B. tropicalis exceeded D. pteronyssinus, no conclusion could be made because there is currently no exposure threshold for triggering acute asthma, for this species. Monthly distribution of B. tropicalis and D. pteronyssinus showed 2 peaks and 4 peaks, respectively. The major peak for D. pteronysinus was in January 1995 whereas for B. tropicalis, the major peak was more variable and occurred between November 1994 to January 1995. Both the species showed minor peak in April 1994.

Matched MeSH terms: Dust/analysis*
Respiratory symptoms and fractional exhaled nitric oxide (FeNO) among students in Penang, Malaysia in relation to signs of dampness at school and fungal DNA in school dust

Norbäck D, Hashim JH, Hashim Z, Cai GH, Sooria V, Ismail SA, et al.

Sci Total Environ, 2017 Jan 15;577:148-154.
PMID: 27802882 DOI: 10.1016/j.scitotenv.2016.10.148

Few health studies exist on dampness and mould in schools in the tropics. We studied associations between fraction of exhaled nitric oxide (FeNO), respiratory symptoms and airway infections among students and dampness and fungal DNA in schools in Malaysia. A total of 368 randomly selected students from 32 classrooms in 8 secondary schools in Penang, Malaysia, participated (58% participation rate). Information on current respiratory symptoms and the home environment was collected by a standardised questionnaire. FeNO was measured by NIOX MINO (50ml/min). The classrooms were inspected and dust was collected by vacuuming on special filters and was analysed for five fungal DNA sequences by quantitative PCR. Linear mixed models and 3-level multiple logistic regression (school, classroom, student) were applied adjusting for demographic data and the home environment. Totally 10.3% reported doctor's diagnosed asthma, 15.1% current wheeze, 12.4% current asthma, 37.3% daytime breathlessness, 10.2% nocturnal breathlessness, 38.9% airway infections and 15.5% had pollen or furry pet allergy. The geometric mean of FeNO was 19.9ppb and 45% had elevated FeNO (>20ppb). Boys had higher levels of FeNO. Chinese had less daytime breathlessness than Malay (OR=0.30: p<0.001). Indoor carbon dioxide levels were low (380-720ppm). Dampness was observed in 18% of the classrooms and was associated with respiratory infections (OR=3.70; 95% CI 1.14-12.1) and FeNO (p=0.04). Aspergillus versicolor DNA was detected in 67% of the classrooms. Higher numbers of Aspergillus versicolor DNA in classroom dust were associated with wheeze (p=0.006), current asthma (p=0.002), respiratory infections (p=0.005) and elevated FeNO levels (p=0.02). In conclusion, respiratory symptoms were common among the students and the high FeNO levels indicate ongoing airway inflammation. Building dampness and the mould Aspergillus versicolor in schools in Malaysia can be risk factors for impaired respiratory health among the students.

Matched MeSH terms: Dust
Ocular symptoms and tear film break up time (BUT) among junior high school students in Penang, Malaysia - Associations with fungal DNA in school dust

Norbäck D, Hashim JH, Hashim Z, Sooria V, Ismail SA, Wieslander G

Int J Hyg Environ Health, 2017 06;220(4):697-703.
PMID: 28254266 DOI: 10.1016/j.ijheh.2017.01.016

BACKGROUND: There are few studies on ocular effects of indoor mould exposure in schools, especially in the tropics OBJECTIVE: To study associations between eye symptoms and tear film break up time (BUT) in students and demographic data and fungal DNA in schools.
METHODS: A school environment study was performed among randomly selected students in eight randomly selected secondary schools in Penang, Malaysia. Information on eye symptoms and demographic data was collected by a standardised questionnaire. BUT was measured by two methods, self-reported BUT (SBUT) and by the non-invasive Tearscope (NIBUT). Dust was collected by vacuuming in 32 classrooms and analysed for five fungal DNA sequences. Geometric mean (GM) for total fungal DNA was 7.31*104 target copies per gram dust and for Aspergillus/Penicillium DNA 3.34*104 target copies per gram dust. Linear mixed models and 3-level multiple logistic regression were applied adjusting for demographic factors.
RESULTS: A total of 368 students (58%) participated and 17.4% reported weekly eye symptoms the last 3 months. The median SBUT and TBUT were 15 and 12s, respectively. Students wearing glasses (OR 2.41, p=0.01) and with a history of atopy (OR=2.67; p=0.008) had more eye symptoms. Girls had less eye symptoms than boys (OR=0.34; p=0.006) Indoor carbon dioxide in the classrooms was low (range 380-720ppm), temperature was 25-30°C and relative air humidity 70-88%. Total fungal DNA in vacuumed dust was associated with shorter SBUT (4s shorter per 105 target copies per gram dust; p=0.04) and NIBUT (4s shorter per 105 target copies per gram dust; p<0.001). Aspergillus/Penicillium DNA was associated with shorter NIBUT (5s shorter per 105 target copies per gram dust; p=0.01).
CONCLUSION: Fungal contamination in schools in a tropical country can be a risk factor for impaired tear film stability among students.

Matched MeSH terms: Dust/analysis*
Fulltext Data on Indoor Air Quality (IAQ) in kindergartens with different surrounding activities

Abdullah S, Abd Hamid FF, Ismail M, Ahmed AN, Wan Mansor WN

Data Brief, 2019 Aug;25:103969.
PMID: 31198825 DOI: 10.1016/j.dib.2019.103969

The aim of the measurement of this data is to evaluate the Indoor Air Quality (IAQ) in terms of chemical and physical parameters. Data were collected at three different kindergartens having different surrounding activities (industrial, institutional, residential area). The chemical parameters measured were respirable suspended particulates of PM10, PM2.5, PM1, carbon monoxide and carbon dioxide, and the concentrations are within the acceptable limit. Physical parameters of wind speed are within the standard, while temperature and relative humidity exceeded the acceptable limit. A strong correlation was found between the chemical IAQ parameters with thermal comfort parameters (temperature and relative humidity). The concentration of IAQ pollutants is higher in order of residential > institutional > industrial.

Matched MeSH terms: Dust; Industry
Fulltext Respiratory symptoms and spirometry findings among pottery makers in Perak

Ibrahim Zubil, AR., Wan Adnan W. A

Journal of Occupational Safety and Health, 2013;10(1):49-58.
MyJurnal

Occupational health hazards as a result to exposure to mineral dust containing silica has been established long time ago in occupational health history. Its effects on lung function and symptom was evaluated in a cross sectional studied among 49 small enterprise pottery workers in the county of Sayong clustered in 3 villages. Respiratory symptoms and lung function was evaluated using MRC respiratory questionnaire 86 and standard spirometry performed. The prevalence of chronic cough, phlegm and chest tightness was 24.5%, 16% and16% respectively. There was no significant decrement in lung function parameters from the predicted normal value with the mean predicted FVC; FEV1 and FEV1/FVC ratio was 85.32%, 83.87% and 99.22 respectively. The relationship between lung symptoms and lung function parameters was evaluated and the result was not significant.

Matched MeSH terms: Dust
Fulltext Seasonal Variation of Particle Number Count (PNC) at the Coastal Environment in Peninsular Malaysia using Boosted Regression Trees (BRTs)

SOBIRATUL NADIA ABDULLAH, NOOR ZAITUN YAHAYA, WAN RAFIZAH WAN WAN ABDULLAH

UMT Journal of Undergraduate Research, 2020;2(3):57-66.
MyJurnal

The concentrations of airborne particulate matter (PM) is often measured as a mass concentration. However, the other way to express particulate matter is by using the Particle Number Count ([PNC]) concentrations. This study aims to analyse the seasonal variation of airborne particulate matter in terms of [PNC] by using R packages and the Boosted Regression Trees (BRTs) technique. The study was conducted at IOES, Universiti of Malaya in Bachok, Kelantan. The monitoring was important to understand the variability of seasonal effects due to different seasons. In this work, only the datasets for three seasons (Inter Monsoon, North East Monsoon and South-West Monsoon) were analysed involving 25,958 data. The air quality monitoring equipment involved was the particle counter Environment Dust Monitor GRIMM Model 180 and a weather station for recording the meteorological parameters. The data analysis was completed by using R software and its package for evaluating seasonal variability and providing the statistical analysis. The relationship between variables was studied by using the Boosted Regression Tree (BRT) technique. The interaction between independent variables towards the [PNC] in different seasons was discussed. The best setting result of BRT model evaluation R² is 0.22 (North-East Monsoon), 0.87 (Intern monsoon 1), and 0.59 for South West Monsoon which indicated that the model developed is acceptable except for NEM and intern monsoon seasons. Temperature (57 %) and wind direction (67%) were found to be the highest factor influenced by the formation of [PNC] concentrations in this area. Finally, good results indicated that BRT technique is an acceptable way to analysed air pollution data.

Matched MeSH terms: Dust
On a new species of Dermatophagoides (D. neotropicalis) from house dust, producing both normal and heteromorphic males (Sarcoptiformes: Pyroglyphidae)

Fain A, Van Bronswijk JE

Acarologia, 1973 Sep;15(1):181-7.
PMID: 4794998
Matched MeSH terms: Dust
House dust mite allergy in Malaysia: review of research gaps in the current scenario and the way forward

Lee YZ, Kow ASF, Jacquet A, Lee MT, Tham CL

Exp Appl Acarol, 2023 Dec;91(4):509-539.
PMID: 37995026 DOI: 10.1007/s10493-023-00857-5

The prevalence of house dust mite (HDM) allergy, especially in Asian countries with rapid urbanization, has been increasing. House dust mites thrive in places with relatively high humidity. With the combination of climate change, naturally high humidity, and urbanization, tropical countries like Malaysia are becoming a hotspot for HDM allergy fast. With a previously reported sensitization rate of between 60 and 80%, it is a worrying trend for Malaysia. However, due to incomplete and out-of-date data, as seen by the limited study coverage in the past, these numbers do not paint a complete picture of the true HDM allergy scene in Malaysia. This review briefly discusses the HDM fauna, the HDM sensitization rate, the common diagnosis and therapeutic tools for HDM allergy in Malaysia, and makes suggestions for possible improvements in the future. This review also highlights the need of more comprehensive population-based prevalence studies to be done in Malaysia, encompassing the three main HDMs-Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis-as the lack of up-to-date studies failed to give a clearer picture on the current scenario of HDM allergy in Malaysia. Future studies will be beneficial to the nation in preparing a better blueprint for the management and treatment of HDM allergy.

Matched MeSH terms: Dust/analysis
Epidemiology of chronic (perennial) rhinitis in Singapore: prevalence estimates, demographic variation and clinical allergic presentation

Ng TP, Tan WC

Ann Acad Med Singap, 1994 Jan;23(1):83-8.
PMID: 8185279

We conducted a population-based study involving a stratified cluster disproportionate random sample of 2868 adults aged 20 to 74 years selected from five housing estates (Yishun, Toa Payoh, Jurong East, Geylang/Eunos and Bukit Merah). Chronic rhinitis was defined as the usual presence of symptoms of blocked or running nose, apart from colds or the flu, lasting for more than a year. Allergic rhinitis was considered to be present if these symptoms were associated with conjunctivitis or recognisable provocation by commonly known allergens, namely house dust, dogs, cats, birds, pollen, or medicines. The estimated general population prevalence of chronic rhinitis was 10.8% (95% confidence interval (CI) 8.8-12.7). Higher prevalences were noted in males, in younger adults, in Indians and Chinese, in those with higher socio-economic status, and in Toa Payoh, Jurong East and Geylang/Eunos. The prevalence of allergic rhinitis was 5.5% (95% CI 4.5-6.5). The most common 'allergenic' factor in allergic rhinitis was house dust (73%); provocation by birds, cats or dogs (5%), grass or tree pollens (5%), and medicine (5%) was less common but likely to have been under-recognised. Provocation by change in temperature (54%) and early in the morning (64%) was equally frequent in both 'allergic' and 'non-allergic' rhinitis; cigarette smoke, petrol and diesel fumes, food and work environment were less common (4-12%). Allergic rhinitis was highly significantly associated with asthma (13.9% in allergic rhinitis, 4.4% in non-allergic rhinitis, and 2.2% in non-rhinitic subjects).

Matched MeSH terms: Dust
Fulltext PARTICULATE RESUSPENSION DURING THE USE OF VACUUM CLEANERS ON OFFICE CARPETS IN UNIVERSITI MALAYSIA TERENGGANU

SYAFIQAH ASYIQIN ROHADI, IZAN JAAFAR, ISMANIZA ISMAIL, TENGKU AZMINA IBRAHIM

UMT Journal of Undergraduate Research, 2020;2(2):41-48.
MyJurnal

The household activities such as vacuuming may elevate the concentration of particulate matter in indoor environments. Cleaning workers and occupants inside closed room may be exposed to the fine particulate matter and at risk of developing numerous respiratory symptoms. This study aims to determine the concentration of the particulate matter (PM10 and PM2.5) that might arise during vacuuming activities and estimated the surface compartmental residence time of particulate matter in indoor environment after each vacuuming activities. The PM10 and PM2.5 concentrations throughout vacuuming were measured in forty-seven offices in Universiti Malaysia Terengganu using the TSI Dust Track DRX. Based on the concentrations measured, the surface compartmental residence time was then estimated using standardized equations taken from literature. The result shows that highest particulate matter concentration was nearly eleven times higher than the World Health Organization guidelines of 25 µg/m3 for PM2.5 concentration (PM2.5 was 270 µg/m3, PM10 was 421 µg/m3), while the particulate matter were estimated to remain lingers inside the air for around 1-4 days before being deposited on the surface. In conclusion, the usage of vacuum cleaners may contribute to more particulate matter being released inside the air due to the resuspension phenomenon. Therefore, it is important for the occupants to maintain proper ventilation after each vacuuming activities took place.

Matched MeSH terms: Dust
Composition and source apportionment of surfactants in atmospheric aerosols of urban and semi-urban areas in Malaysia

Wahid NB, Latif MT, Suratman S

Chemosphere, 2013 Jun;91(11):1508-16.
PMID: 23336924 DOI: 10.1016/j.chemosphere.2012.12.029

This study was conducted to determine the composition and source apportionment of surfactant in atmospheric aerosols around urban and semi-urban areas in Malaysia based on ionic compositions. Colorimetric analysis was undertaken to determine the concentrations of anionic surfactants as Methylene Blue Active Substances (MBAS) and cationic surfactants as Disulphine Blue Active Substances (DBAS) using a UV spectrophotometer. Ionic compositions were determined using ion chromatography for cations (Na(+), NH4(+), K(+), Mg(2+), Ca(2+)) and anions (F(-), Cl(-), NO3(-), SO4(2-)). Principle component analysis (PCA) combined with multiple linear regression (MLR) were used to identify the source apportionment of MBAS and DBAS. Results indicated that the concentrations of surfactants at both sampling sites were dominated by MBAS rather than DBAS especially in fine mode aerosols during the southwest monsoon. Three main sources of surfactants were identified from PCA-MLR analysis for MBAS in fine mode samples particularly in Kuala Lumpur, dominated by motor vehicles, followed by soil/road dust and sea spray. Besides, for MBAS in coarse mode, biomass burning/sea spray were the dominant source followed by motor vehicles/road dust and building material.

Matched MeSH terms: Dust/analysis
Surfactants in the sea surface microlayer, subsurface water and fine marine aerosols in different background coastal areas

Shaharom S, Latif MT, Khan MF, Yusof SNM, Sulong NA, Wahid NBA, et al.

Environ Sci Pollut Res Int, 2018 Sep;25(27):27074-27089.
PMID: 30019134 DOI: 10.1007/s11356-018-2745-0

This study aims to determine the concentrations of surfactants in the surface microlayer (SML), subsurface water (SSW) and fine mode aerosol (diameter size dust (23%) and sulphate/fresh sea salt (8%). During the southwest monsoon, the three main sources of atmospheric aerosol were biomass burning (71%), secondary inorganic aerosol (23%) and sea spray (6%). This study suggests anthropogenic sources are main contributors to the concentrations of surfactants in SML, SSW and fine aerosols.

Matched MeSH terms: Dust/analysis
Association between indoor microbiome exposure and sick building syndrome (SBS) in junior high schools of Johor Bahru, Malaysia

Fu X, Norbäck D, Yuan Q, Li Y, Zhu X, Hashim JH, et al.

Sci Total Environ, 2021 Jan 20;753:141904.
PMID: 32890872 DOI: 10.1016/j.scitotenv.2020.141904

Sick building syndrome (SBS) is a collection of nonspecific syndromes linked with the built environment. The occurrence of SBS is associated with humidity, ventilation, moulds and microbial compounds exposure. However, no study has reported the association between indoor microbiome and SBS. In this study, 308 students were surveyed for SBS symptoms from 21 classrooms of 7 junior high schools from Johor Bahru, Malaysia, and vacuum dust from floor, desks and chairs was collected. High throughput amplicon sequencing (16S rRNA gene and ITS region) and quantitative PCR were conducted to characterize the absolute concentration of bacteria and fungi taxa. In total, 326 bacterial and 255 fungal genera were detected in dust with large compositional variation among classrooms. Also, half of these samples showed low compositional similarity to microbiome data deposited in the public database. The number of observed OTUs in Gammaproteobacteria was positively associated with SBS (p = 0.004). Eight microbial genera were associated with SBS (p

Matched MeSH terms: Dust
Fulltext Associations between the indoor microbiome, environmental characteristics and respiratory infections in junior high school students of Johor Bahru, Malaysia

Fu X, Yuan Q, Zhu X, Li Y, Meng Y, Hashim JH, et al.

Environ Sci Process Impacts, 2021 Aug 01;23(8):1171-1181.
PMID: 34278392 DOI: 10.1039/d1em00115a

Pathogens are commonly present in the human respiratory tract, but symptoms are varied among individuals. The interactions between pathogens, commensal microorganisms and host immune systems are important in shaping the susceptibility, development and severity of respiratory diseases. Compared to the extensive studies on the human microbiota, few studies reported the association between indoor microbiome exposure and respiratory infections. In this study, 308 students from 21 classrooms were randomly selected to survey the occurrence of respiratory infections in junior high schools of Johor Bahru, Malaysia. Vacuum dust was collected from the floor, chairs and desks of these classrooms, and high-throughput amplicon sequencing (16S rRNA and ITS) and quantitative PCR were conducted to characterize the absolute concentration of the indoor microorganisms. Fifteen bacterial genera in the classes Actinobacteria, Alphaproteobacteria, and Cyanobacteria were protectively associated with respiratory infections (p < 0.01), and these bacteria were mainly derived from the outdoor environment. Previous studies also reported that outdoor environmental bacteria were protectively associated with chronic respiratory diseases, such as asthma, but the genera identified were different between acute and chronic respiratory diseases. Four fungal genera from Ascomycota, including Devriesia, Endocarpon, Sarcinomyces and an unclassified genus from Herpotrichillaceae, were protectively associated with respiratory infections (p < 0.01). House dust mite (HDM) allergens and outdoor NO2 concentration were associated with respiratory infections and infection-related microorganisms. A causal mediation analysis revealed that the health effects of HDM and NO2 were partially or fully mediated by the indoor microorganisms. This is the first study to explore the association between environmental characteristics, microbiome exposure and respiratory infections in a public indoor environment, expanding our understanding of the complex interactions among these factors.

Matched MeSH terms: Dust/analysis

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