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Fulltext Allergies in asthma

Zulkifli A, Ng WH, Chelvam P

Family Practitioner, 1979;3(5):32-34.

148 patients, 79 males and 60 females were seen in 1978 at Medical Unit Universiti Kebangsaan Kuala Lumpur. For majority of the patients the attacks of asthma begin at an early age. History of allergies were found in majority of the patients. Family history of asthma was noted in about 50%. Of the allergens that triggers of an attack of asthma, household dusts, rhinitis and pollen tops the list. Of the food the common allergens were shrimps, eggs and crabs. Most of the above allergens can be avoided or counteracted.
Study site: Medical Unit, Hospital Kuala Lumpur (UKM unit), Malaysia

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
Anthropogenic emissions of atomic chlorine precursors in the Yangtze River Delta region, China

Yi X, Yin S, Huang L, Li H, Wang Y, Wang Q, et al.

Sci Total Environ, 2021 Jun 01;771:144644.
PMID: 33736175 DOI: 10.1016/j.scitotenv.2020.144644

Chlorine radical plays an important role in the formation of ozone and secondary aerosols in the troposphere. It is hence important to develop comprehensive emissions inventory of chlorine precursors in order to enhance our understanding of the role of chlorine chemistry in ozone and secondary pollution issues. Based on a bottom-up methodology, this study presents a comprehensive emission inventory for major atomic chlorine precursors in the Yangtze River Delta (YRD) region of China for the year 2017. Four primary chlorine precursors are considered in this study: hydrogen chloride (HCl), fine particulate chloride (Cl-) (Cl- in PM2.5), chlorine gas (Cl2), and hypochlorous acid (HClO) with emissions estimated for twelve source categories. The total emissions of these four species in the YRD region are estimated to be 20,424 t, 15,719 t, 1556 and 9331 t, respectively. The emissions of HCl are substantial, with major emissions from biomass burning and coal combustion, together accounting for 68% of the total HCl emissions. Fine particulate Cl- is mainly emitted from industrial processing, biomass burning and waste incineration. The emissions of Cl2 and HClO are mainly associated with usage of chlorine-containing disinfectants, for example, water treatment, wastewater treatment, and swimming pools. Emissions of each chlorine precursor are spatially allocated based on the characteristics of individual source category. This study provides important basic dataset for further studies with respect to the effects of chlorine chemistry on the formation of air pollution complex in the YRD region.

Matched MeSH terms: Dust
Melioidosis pneumonia and blast injury

Wang CY, Yap BH, Delilkan AE

Chest, 1993 Jun;103(6):1897-9.
PMID: 8404124

We present the case of a 24-year-old woman with acute septicemic melioidosis resulting from inhaled infective dust during a blast injury. With appropriate antibiotic treatment and supportive therapy in the ICU, the patient made an uneventful recovery.

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
Characteristics and health effect of heavy metals on non-exhaust road dusts in Kuala Lumpur

Wahab MIA, Razak WMAA, Sahani M, Khan MF

Sci Total Environ, 2020 Feb 10;703:135535.
PMID: 31767333 DOI: 10.1016/j.scitotenv.2019.135535

This study aimed to assess the concentrations and health effect of trace metals [cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)] on the road dust of selected locations in the city of Kuala Lumpur. Sampling was conducted thrice at four locations, namely, Tun Razak Road, Raja Abdullah Road, Tunku Abdul Rahman (TAR) Road, and Ayer Molek Road. The concentrations of trace metals in road dust were analyzed by inductively coupled plasma mass spectrometry. TAR Road presented the highest Cd, Cu, Ni, and Pb contents compared with the other roads. The pollution level of trace metals in road dust was assessed by pollution index and pollution load index (PLI), showing that all studied locations were highly contaminated except Ayer Molek Road. Based on the PLI value, the sequence of pollution in descending order is as follows: TAR Road > Raja Abdullah Road > Tun Razak Road > Ayer Molek Road. Health risk assessment was performed to assess the health effects of carcinogenic and noncarcinogenic pollutants caused by the exposure to trace metals in road dust on adults and children. Based on the integrated hazard index values for children at all locations, >1 indicates a possible noncarcinogenic effect. All incremental lifetime cancer risk values for adult and children at all locations are within acceptable limits and are considered safe.

Matched MeSH terms: Dust/analysis*
Vertical distribution of smoke aerosols over upper Indo-Gangetic Plain

Vinjamuri KS, Mhawish A, Banerjee T, Sorek-Hamer M, Broday DM, Mall RK, et al.

Environ Pollut, 2020 Feb;257:113377.
PMID: 31672363 DOI: 10.1016/j.envpol.2019.113377

Attenuated backscatter profiles retrieved by the space borne active lidar CALIOP on-board CALIPSO satellite were used to measure the vertical distribution of smoke aerosols and to compare it against the ECMWF planetary boundary layer height (PBLH) over the smoke dominated region of Indo-Gangetic Plain (IGP), South Asia. Initially, the relative abundance of smoke aerosols was investigated considering multiple satellite retrieved aerosol optical properties. Only the upper IGP was selectively considered for CALIPSO retrieval based on prevalence of smoke aerosols. Smoke extinction was found to contribute 2-50% of the total aerosol extinction, with strong seasonal and altitudinal attributes. During winter (DJF), smoke aerosols contribute almost 50% of total aerosol extinction only near to the surface while in post-monsoon (ON) and monsoon (JJAS), relative contribution of smoke aerosols to total extinction was highest at about 8 km height. There was strong diurnal variation in smoke extinction, evident throughout the year, with frequent abundance of smoke particles at lower height (<4 km) during daytime compared to higher height during night (>4 km). Smoke injection height also varied considerably during rice (ON: 0.71 ± 0.65 km) and wheat (AM: 2.34 ± 1.34 km) residue burning period having a significant positive correlation with prevailing PBLH. Partitioning smoke AOD against PBLH into the free troposphere (FT) and boundary layer (BL) yield interesting results. BL contribute 36% (16%) of smoke AOD during daytime (nighttime) and the BL-FT distinction increased particularly at night. There was evidence that despite travelling efficiently to FT, major proportion of smoke AOD (50-80%) continue to remain close to the surface (<3 km) thereby, may have greater implications on regional climate, air quality, smoke transport and AOD-particulate modelling.

Matched MeSH terms: Dust/analysis
Chemical characteristics of rainwater in the tropical rainforest region in northwestern Borneo

Valappil NKM, Viswanathan PM, Hamza V

Environ Sci Pollut Res Int, 2020 Jun 23.
PMID: 32572749 DOI: 10.1007/s11356-020-09542-1

A comprehensive study of the chemical composition of rainwater was carried out from October 2016 to September 2017 in the equatorial tropical rainforest region of northwestern Borneo. Monthly cumulative rainwater samples were collected from different locations in the Limbang River Basin (LRB) and were later categorized into seasonal samples representing northeast monsoon (NEM), southwest monsoon (SWM), and inter-monsoon (IM) periods. Physical parameters (pH, EC, TDS, DO, and turbidity), major ions (HCO3-, Cl-, Ca2+, Mg2+, Na+, and K+) and trace metals (Co, Ni, Cd, Fe, Mn, Pb, Zn, and Cu) were analyzed from collected rainwater samples. Rainwater is slightly alkaline with mean pH higher than 5.8. Chloride and bicarbonate are the most abundant ions, and the concentration of major ions in seasonal rainwater has shown slight variation which follows a descending order of HCO3-> Cl-> Na+ > Ca2+ > Mg2+ > K+ in NEM and Cl- > HCO3- > Na+ > Ca2+ > K+ > Mg2+ in SWM and Cl- > HCO3- > Na+ > Ca2+ > Mg2+ > K+ in IM period. Trace metals such as Fe and Ni have shown dominance in seasonal rainwater samples, and all the metals have shown variation in concentration in different seasons. Variation in chemical characteristic of seasonal rainwater samples identified through piper diagram indicates dominance of Ca2+-Mg2+-HCO3- and mixed Ca2+-Mg2+-Cl- facies during NEM, SWM, and IM periods. Statistical analysis of the results through two-way ANOVA and Pearson's correlation also indicates significant variation in physico-chemical characteristics. This suggests a variation in contributing sources during the monsoon seasons. Factor analysis confirmed the source variation by explaining the total variance of 79.80%, 90.72%, and 90.52% with three factor components in NEM, SWM, and IM rainwater samples with different loading of parameters. Enrichment factor analysis revealed a combined contribution of marine and crustal sources except K+ which was solely from crustal sources. Sample analysis of backward air mass trajectory supports all these findings by explaining seasonal variation in the source of pollutants reaching the study area. Overall, the results show that the chemical composition of seasonal rainwater samples in LRB was significantly influenced by natural as well as anthropogenic processes. These include (long-range and local) industrial activities, fossil fuel combustion, forest burning, transportation activities including road transport and shipping activities, and land-derived soil dust along with chemical constituents carried by seasonal wind.

Matched MeSH terms: Dust
Fabrication, characterization, and application of light weight thermal insulation material from combined buffing dust and plaster of paris for construction industry

Ulfat W, Mohyuddin A, Amjad M, Othman MHD, Gikas P, Kurniawan TA

J Environ Manage, 2023 Dec 01;347:119129.
PMID: 37778073 DOI: 10.1016/j.jenvman.2023.119129

Buffing dust, generated from tannery industries, is a source of air pollution in Pakistan. Valorization of the waste into another useful material is important to deal with the environmental pollution, while reducing waste disposal costs in landfills. To demonstrate its technological strength, this work fabricates a thermal insulation material made of plaster of Paris and the buffing dust (from tanning waste) in the form of a composite with superior mechanical properties and low thermal conductivity. Buffing dust with concentrations ranging from 5 to 20% (w/w) were loaded in the composite. The samples synthesized were made slurry of plaster of Paris, buffing dust, and water at ambient temperature. The physico-mechanical properties of composite were analyzed. It was found that the composite had better thermal insulation properties than the panels of the plaster of Paris. Its thermal conductivity was reduced to 15% after adding buffing dust (20% w/w). All the materials had physico-chemical properties like tensile strength (0.02 MPa and 0.06 MPa), density (700-400 kg/m3), water absorption (5.2-8.6%) and thermal conductivity (0.17000-0.09218 W/m-K). Thermogravimetric analysis showed that the material was thermally stable at temperatures ranging from 145 to 177 °C, while FT-IR results revealed that the composite contained O-H, N-H, and CO functional groups. SEM analysis displayed that the composite's homogeneity was reduced with low voids due to buffing dust addition, while EDX analysis showed that the composite contained 23.62% of S, 26.76% of Ca, 49.2% of O and 0.42% of C. This implies that buffing dust could be recycled to manufacture heat insulation materials for construction sector to reduce air pollution, while minimizing energy consumption. By integrating the buffing dust from tanning waste and the plaster of Paris as a composite for construction sector, this work promotes the recycling of unused waste, while saving public funds. Instead of paying landfill fees and polluting soil, the waste may be recycled at lower cost, while reducing environmental damage.

Matched MeSH terms: Dust; Construction Industry*
Fulltext Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case-control study

Too CL, Muhamad NA, Ilar A, Padyukov L, Alfredsson L, Klareskog L, et al.

Ann Rheum Dis, 2016 06;75(6):997-1002.
PMID: 26681695 DOI: 10.1136/annrheumdis-2015-208278

OBJECTIVES: Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke.

METHODS: Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case-control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI.

RESULTS: Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2).

CONCLUSIONS: This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene-environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

Matched MeSH terms: Dust*; Textile Industry
Mass rearing of mites collected from house-dust samples

Thomas V, Leng YP, Hay TB

Med J Malaysia, 1976 Jun;30(4):331-3.
PMID: 979741
Matched MeSH terms: Dust*
Dermatophagoides pteronyssinus and house dust allergy in west Malaysia

Thomas V, Bock Hay Am Tan, Rajapaksa AC

Ann Allergy, 1978 Feb;40(2):114-6.
PMID: 629426

Three groups of people with different clinical histories and manifestations to house dust were skin tested with Dermatophagoides pteronyssinus extracts. The results showed close correlation between positive skin tests and clinical sensitivity to dust. The correlation was not, however, perfect and, although D. pteronyssinus is a major factor in house dust allergy, it does not appear to be the sole antigen involved.

Matched MeSH terms: Dust*
Fulltext Ganoderma neo-japonicum Imazeki revisited: Domestication study and antioxidant properties of its basidiocarps and mycelia

Tan WC, Kuppusamy UR, Phan CW, Tan YS, Raman J, Anuar AM, et al.

Sci Rep, 2015;5:12515.
PMID: 26213331 DOI: 10.1038/srep12515

Mushroom cultivation benefits humankind as it deliberately encourages wild mushrooms to be commercially propagated while recycling agricultural wastes. Ganoderma neo-japonicum is a rare polypore mushroom found growing on decaying Schizostachyum brachycladium (a tropical bamboo) clumps in Malaysia. The Malaysian indigenous tribes including the Temuans and Temiars use the basidiocarps of G. neo-japonicum to treat various ailments including diabetes. In this study, the domestication of G. neo-japonicum in artificial logs of different agricultural residues was investigated. Sawdust promoted the mycelia spawn colonisation in the shortest period of 38 ± 0.5 days. However, only sawdust and bamboo dust supported the primodia formation. Complex medium supported mycelium growth in submerged cultures and 27.11 ± 0.43 g/L of mycelia was obtained after 2 weeks of cultivation at 28 °C and 200 rpm. Antioxidant potential in mushroom may be influenced by different cultivation and extraction methods. The different extracts from the wild and cultivated basidiocarps as well as mycelia were then tested for their antioxidant properties. Aqueous and ethanol extracts of mycelia and basidiocarps tested had varying levels of antioxidant activities. To conclude, domestication of wild G. neo-japonicum using agroresidues may ensure a continuous supply of G. neo-japonicum for its medicinal use while ensuring the conservation of this rare species.

Matched MeSH terms: Dust
Heavy metal quantification of classroom dust in school environment and its impacts on children health from Rawang (Malaysia)

Tan SY, Praveena SM, Abidin EZ, Cheema MS

Environ Sci Pollut Res Int, 2018 Dec;25(34):34623-34635.
PMID: 30315534 DOI: 10.1007/s11356-018-3396-x

This study aimed to determine bioavailable heavy metal concentrations (As, Cd, Co, Cu, Cr, Ni, Pb, Zn) and their potential sources in classroom dust collected from children's hand palms in Rawang (Malaysia). This study also aimed to determine the association between bioavailable heavy metal concentration in classroom dust and children's respiratory symptoms. Health risk assessment (HRA) was applied to evaluate health risks (non-carcinogenic and carcinogenic) due to heavy metals in classroom dust. The mean of bioavailable heavy metal concentrations in classroom dust found on children's hand palms was shown in the following order: Zn (1.25E + 01 μg/g) > Cu (9.59E-01 μg/g) > Ni (5.34E-01 μg/g) > Cr (4.72E-02 μg/g) > Co (2.34E-02 μg/g) > As (1.77E-02 μg/g) > Cd (9.60E-03 μg/g) > Pb (5.00E-03 μg/g). Hierarchical cluster analysis has clustered 17 sampling locations into three clusters, whereby cluster 1 (S3, S4, S6, S15) located in residential areas and near to roads exposed to vehicle emissions, cluster 2 (S10, S12, S9, S7) located near Rawang town and cluster 3 (S13, S16, S1, S2, S8, S14, S11, S17, S5) located near industrial, residential and plantation areas. Emissions from vehicles, plantations and industrial activities were found as the main sources of heavy metals in classroom dust in Rawang. There is no association found between bioavailable heavy metal concentrations and respiratory symptoms, except for Cu (OR = 0.03). Health risks (non-carcinogenic and carcinogenic risks) indicated that there are no potential non-carcinogenic and carcinogenic risks of heavy metals in classroom dust toward children health.

Matched MeSH terms: Dust/analysis*
Fulltext Association of exposure to PM2.5 and PM10 with DNA damage in exfoliated buccal mucosa cells among primary school children living nearby palm oil activity at Semenyih, Selangor

Syhidatul Farhana Othman, Juliana Jalaludin, Nur Hazirah Hisamuddin, Noeroel Widajati

Malaysian Journal of Medicine and Health Sciences, 2019;15(204):130-135.
MyJurnal

Introduction: Exposure of PM2.5 and PM10 released from combustion of biomass activity caused respiratory health among children. Objective: This study aims to determine the association between exposure of PM2.5 and PM10 with DNA damage in primary school children living nearby palm oil combustion activity at Semenyih. Methods: A cross sectional comparative study were conducted among Malay primary school children in school A located 2.7km from palm oil activity (N=82) and school B located about 40km away from the palm oil area (N=85). A standardized ques- tionnaire were distributed to respondent’s parents. Concentrations of PM2.5 and PM10 were measured by using Dust Trak DRX Aerosol Monitor Model 8534 and Escort LC Personal Sampling Pump. Measurement of indoor and outdoor air pollutants were conducted in schools and home. Buccal cells were collected, which then followed by micronu- cleus assay. Results: Concentration of PM10 and PM2.5 at home of studied group were significantly higher compared to comparative group with p value (p=0.007) and (p=0.018) respectively. PM10 and PM2.5 of studied schools were significantly higher compared to comparative schools with p value (p=0.014) and (p=0.04) respectively. MN fre- quencies of studied group were significantly higher compared to comparative group (p=0.001). Significant difference of respiratory symptoms were found between two groups which are cough, phlegm, wheezing and chest tightness (p=0.001). There were significant correlation between PM10 with MN frequency of studied group and comparative group with r= 0.562; p=0.001. Conclusion: This study indicated that the exposure of PM10 and PM2.5 would increase the risk of having respiratory health symptoms and might induce the micronuclei formation among children who lived near palm oil activity area.

Matched MeSH terms: Dust
Fulltext Indoor microbiome, microbial and plant metabolites, chemical compounds, and asthma symptoms in junior high school students: a multicentre association study in Malaysia

Sun Y, Zhang M, Ou Z, Meng Y, Chen Y, Lin R, et al.

Eur Respir J, 2022 Nov;60(5).
PMID: 35618276 DOI: 10.1183/13993003.00260-2022

BACKGROUND: Indoor microbial exposure is associated with asthma, but the health effects of indoor metabolites and chemicals have not been comprehensively assessed.
METHODS: We collected classroom dust from 24 junior high schools in three geographically distanced areas in Malaysia (Johor Bahru, Terengganu and Penang), and conducted culture-independent high-throughput microbiome and untargeted metabolomics/chemical profiling.
RESULTS: 1290 students were surveyed for asthma symptoms (wheeze). In each centre, we found significant variation in the prevalence of wheeze among schools, which could be explained by personal characteristics and air pollutants. Large-scale microbial variations were observed between the three centres; the potential protective bacteria were mainly from phyla Actinobacteria in Johor Bahru, Cyanobacteria in Terengganu and Proteobacteria in Penang. In total, 2633 metabolites and chemicals were characterised. Many metabolites were enriched in low-wheeze schools, including plant secondary metabolites flavonoids/isoflavonoids (isoliquiritigenin, formononetin, astragalin), indole and derivatives (indole, serotonin, 1H-indole-3-carboxaldehyde), and others (biotin, chavicol). A neural network analysis showed that the indole derivatives were co-occurring with the potential protective microbial taxa, including Actinomycetospora, Fischerella and Truepera, suggesting these microorganisms may pose health effects by releasing indole metabolites. A few synthetic chemicals were enriched in high-wheeze schools, including pesticides (2(3H)-benzothiazolethione), fragrances (2-aminobenzoic acid, isovaleric acid), detergents and plastics (phthalic acid), and industrial materials (4,4-sulfonyldiphenol).
CONCLUSIONS: This is the first association study between high-throughput indoor chemical profiling and asthma symptoms. The consistent results from the three centres indicate that indoor metabolites/chemicals could be a better indicator than the indoor microbiome for environmental and health assessments, providing new insights for asthma prediction, prevention and control.

Matched MeSH terms: Dust/analysis
Fulltext Comparison of direct method and indirect methods for sampling and analysis of airborne respirable crystaline silica by X-ray difractometer

Suhaily Amran, Ahmad Sayuti Zainal Abidin, Shoffian Amin Jaafar, Mohd Talib Latif, Abdul Mutalib Leman

Journal of Occupational Safety and Health, 2015;12(1):137-141.
MyJurnal

There are several alternative sampling and analytical methods available for the determination of respirable
crystalline silica exposure among workers. The commonly used ones are, (1) NIOSH Manual Analytical Method
No.7500(NMAM 7500) which is Silica, crystalline, by X-ray difractometer via filter deposition(NIOSH 2003), and
(2) MDHS 101 (Methods for the Determination of Hazardous Substances (MDHS) Guidance No.101: Respirable
crystalline silica in respirable airborne dust). The aim of this study is to compare applicability of respirable crystalline
silica sampling and analysis between method MDHS 101 and NMAM 7500. Laboratory procedures will be performed
strictly based on MDHS 101 and NMAM 7500. Both methods apply X-ray diffraction as analytical technique with
many variations on sampling techniques and laboratory preparations. Quality assurance values such as detection
limits, accuracy and precision are derived from both data and will be compared to determine which of the method
establishes better quality assurance. The method which establishes better quality assurance will be recommend to be
used in Malaysian respirable crystalline silica monitoring programme. The strength of this research lies on its potential
to provide local capabilities in analysis of respirable crystalline silica in Malaysian setting.

Matched MeSH terms: Dust
Thermal radiation effects on heat and mass transfer of magnetohydrodynamics dusty jeffrey fluid past an exponentially stretching sheet

Siti Nur Haseela Izani, Anati Ali

MATEMATIKA, 2019;35(2):187-200.
MyJurnal

The heat and mass transfer of steady magnetohydrodynamics of dusty Jeffrey fluid past an exponentially stretching sheet in the presence of thermal radiation have been investigated. The main purpose of this study is to conduct a detailed analysis of flow behaviour of suspended dust particles in non-Newtonian fluid. The governing equations hav been converted into dimensionless form, and then solved numerically via the Keller-box method. The expression of Sherwood number, Nusselt number and skin friction have been evaluated, and then displayed in tabular forms. Velocity, temperature and concentration profiles are presented graphically. It is observed that large value of dust particles mass concentration parameter has reduced the flow velocity significantly. Increase in radiation parameter enhances the temperature, whereas the increment in Schmidt number parameter reduces the concentration.

Matched MeSH terms: Dust
Insights into size-segregated particulate chemistry and sources in urban environment over central Indo-Gangetic Plain

Singh N, Banerjee T, Murari V, Deboudt K, Khan MF, Singh RS, et al.

Chemosphere, 2021 Jan;263:128030.
PMID: 33297051 DOI: 10.1016/j.chemosphere.2020.128030

Size-segregated airborne fine (PM2.1) and coarse (PM>2.1) particulates were measured in an urban environment over central Indo-Gangetic plain in between 2015 and 2018 to get insights into its nature, chemistry and sources. Mean (±1σ) concentration of PM2.1 was 98 (±76) μgm-3 with a seasonal high during winter (DJF, 162 ± 71 μgm-3) compared to pre-monsoon specific high in PM>2.1 (MAMJ, 177 ± 84 μgm-3) with an annual mean of 170 (±69) μgm-3. PM2.1 was secondary in nature with abundant secondary inorganic aerosols (20% of particulate mass) and water-soluble organic carbon (19%) against metal enriched (25%) PM>2.1, having robust signature of resuspensions from Earth's crust and road dust. Ammonium-based neutralization of particulate acidity was essentially in PM2.1 with an indication of predominant H2SO4 neutralization in bisulfate form compared to Ca2+ and Mg2+-based neutralization in PM>2.1. Molecular distribution of n-alkanes homologues (C17-C35) showed Cmax at C23 (PM2.1) and C18 (PM>2.1) with weak dominance of odd-numbered n-alkanes. Carbon preference index of n-alkanes was close to unity (PM2.1: 1.4 ± 0.3; PM>2.1: 1.3 ± 0.4). Fatty acids (C12-C26) were characterized with predominance of even carbon with Cmax at n-hexadecanoic acid (C16:0). Low to high molecular weight fatty acid ratio ranged from 2.0 (PM>2.1) to 5.6 (PM2.1) with vital signature of anthropogenic emissions. Levoglucosan was abundant in PM2.1 (758 ± 481 ngm-3) with a high ratio (11.6) against galactosan, emphasizing robust contribution from burning of hardwood and agricultural residues. Receptor model resolves secondary aerosols and biomass burning emissions (45%) as the most influential sources of PM2.1 whereas, crustal (29%) and secondary aerosols (29%) were found responsible for PM>2.1; with significant variations among the seasons.

Matched MeSH terms: Dust/analysis
Molecular distribution, sources and potential health risks of fine particulate-bound polycyclic aromatic hydrocarbons during high pollution episodes in a subtropical urban city

Singh A, Banerjee T, Latif MT, Ramanathan S, Suradi H, Othman M, et al.

Chemosphere, 2023 Nov;340:139943.
PMID: 37625487 DOI: 10.1016/j.chemosphere.2023.139943

Abundance of fine particulate-bound 16 priority polycyclic aromatic hydrocarbons (PAHs) was investigated to ascertain its sources and potential carcinogenic health risks in Varanasi, India. The city represents a typical urban settlement of South Asia having particulate exposure manyfold higher than standard with reports of pollution induced mortalities and morbidities. Fine particulates (PM2.5) were monitored from October 2019 to May 2020, with 32% of monitoring days accounting ≥100 μgm-3 of PM2.5 concentration, frequently from November to January (99% of monitoring days). The concentration of 16 priority PAHs varied from 24.1 to 44.6 ngm-3 (mean: 33.1 ± 3.2 ngm-3) without much seasonal deviations. Both low (LMW, 56%) and high molecular weight (HMW, 44%) PAHs were abundant, with Fluoranthene (3.9 ± 0.4ngm-3) and Fluorene (3.5 ± 0.3ngm-3) emerged as most dominating PAHs. Concentration of Benzo(a)pyrene (B(a)P, 0.5 ± 0.1ngm-3) was lower than the national standard as it contributed 13% of total PAHs mass. Diagnostic ratios of PAH isomers indicate predominance of pyrogenic sources including emissions from biomass burning, and both from diesel and petrol-driven vehicles. Source apportionment using receptor model revealed similar observation of major PAHs contribution from biomass burning and fuel combustion (54% of source contribution) followed by coal combustion for residential heating and cooking purposes (44%). Potential toxicity of B[a]P equivalence ranged from 0.003 to 1.365 with cumulative toxicity of 2.13ngm-3. Among the PAH species, dibenzo[h]anthracene contributed maximum toxicity followed by B[a]P, together accounting 86% of PAH induced carcinogenicity. Incremental risk of developing cancer through lifetime exposure (ILCR) of PAHs was higher in children (3.3 × 10-4) with 56% contribution from LMW PAHs, primarily through ingestion and dermal contact. Adults in contrast, were more exposed to inhale airborne PAHs with cumulative ILCR of 2.2 × 10-4. However, ILCR to PM2.5 exposure is probably underestimated considering unaccounted metal abundance thus, require source-specific control measures.

Matched MeSH terms: Dust

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