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Displaying publications 41 - 60 of 104 in total

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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 Nasopharyngeal Carcinoma (NPC) Risk Factors: A Systematic Review and Meta-Analysis of the Association with Lifestyle, Diets, Socioeconomic and Sociodemographic in Asian Region

Okekpa SI, S M N Mydin RB, Mangantig E, Azmi NSA, Zahari SNS, Kaur G, et al.

Asian Pac J Cancer Prev, 2019 Nov 01;20(11):3505-3514.
PMID: 31759378 DOI: 10.31557/APJCP.2019.20.11.3505

OBJECTIVE: Risk factors of nasopharyngeal carcinoma (NPC) have been linked with diets, life style and viral
infections. NPC is more rampant in Asian populations than non-Asian countries. Our study aims to assess the validity
of the suggestions provided by multiple case control studies demonstrating that salted fish consumption, smoking and
alcohol consumption are associated with the risk of NPC in Asia.
METHODS: Search for related literature on salted fish,
smoking and alcohol consumption were performed via Science Direct, PubMed databases and Google Scholar. Articles
included in this study were from 2009 to 2017, with specific focus on salted fish, smoking and alcohol consumption
as risk factors of NPC. This study excluded all articles published prior to 2009 and articles involving other cancers.
Data were extracted independently by two different researchers and harmonized. Meta-analysis was conducted on the
obtained data, by using R package Meta to create funnel and forest plots.
RESULTS: The meta-analysis revealed that
salted fish, smoking and alcohol consumption were significantly associated to NPC risk with random effect model score
showing OR of 1.41 at 95% confidence interval (CI) of 1.13-1.75 (P<0.01), OR of 1.89 at 95 % CI of 1.49 - 2.38, and
OR: 1.42 at 95 % CI of 1.23 - 1.65 respectively. Our results also revealed significant association of salted meat, salted
vegetables, house type, wood dust exposure associated with NPC risk with p values less than 0.05.
CONCLUSION: This
study proposes that salted fish intake, smoking and alcohol consumption might be linked to NPC risk in Asians. Further
studies are necessary to ascertain the molecular mechanisms and clarify if the associated path that could function as
therapeutic target.

Matched MeSH terms: Dust
Fulltext Determination of elements (Cd, Cu, Fe, Pb and Zn) in Universiti Teknologi MARA (UiTM) Hostel Shah Alam, Malaysia

Nurzulaifa Shaheera Erne Mohd Yasim, Siti Khadijah Mat Yaacob, Noradila Mohamed

Science Letters, 2018;12(2):28-36.
MyJurnal

The purpose of this study is to determine the concentration of the selected elemental composition in a multi-storey hostel. Dust samples were taken from three random rooms at each level of the student hostel by sweeping the floor. The concentrations of elements (Cd, Cu, Fe, Pb and Zn) were determined by using Inductively Coupled Plasma-Optical Emission Spectrometer (ICPOES) after digestion with nitric acid and sulfuric acid solutions. Dust samples analysis has shown the different levels of sampling point does not affect the concentration of the elements. The concentration of elements in investigated microenvironment was in the order of Fe > Zn > Cu > Pb > Cd. The correlation analysis was applied to elements variable in order to identify the sources of an airborne contaminant. It was discovered the strong positive correlation between Cu-Zn which indicates the sources come from traffic emission and street dust. This result was supported by the Principal Component Analysis (PCA) that revealed the presence of elements in the student hostel originated from the outdoor sources.

Matched MeSH terms: Dust
Fulltext Respiratory symptoms and pulmonary function among male steel workers in Terengganu, Malaysia

Nurul, A.H., Shamsul Bahri, M.T., Noor Hassim, I.

Malaysian Journal of Public Health Medicine, 2014;14(1):10-18.
MyJurnal

A cross sectional study was carried out to determine the relationship between dust exposure and pulmonary function in male steel workers in Terengganu, Malaysia. The investigation included spirometric testing and detailed personal interviews using a structured questionnaire adopted from British Medical Research Council (BRMC) Questionnaire on respiratory symptoms. Respiratory symptoms commonly reported by the male workers were morning phlegm (33.1%), shortness of breath (31.9%), chest tightness (30.4%), and morning cough (17.8%). Age and duration of employment were among the factors associated with respiratory symptoms (p

Matched MeSH terms: Dust
Fulltext Dust exposure and respiratory health of workers in a steel mill in Terengganu, Malaysia

Nurul Ainun Hamzah, Shamsul Bahri Mohd Tamrin, Noor Hassim Ismail

Journal of Occupational Safety and Health, 2018;15(1):1-16.
MyJurnal

Air pollution in steel making operations effect to respiratory health. This study aimed to measure the dust exposure and evaluate the respiratory health among steel workers. A cross sectional study was conducted among 402 male workers. Respiratory symptoms using British Medical Research Council (BMRC) Questionnaire while lung function was measured The airborne dust [PM2.5, PM10, and Total Particulate Matter (TPM)] were monitored by Handheld 3016 Counter. All the parameters studied exceeded the limit of Malaysian guideline standard. Prevalence of chronic phlegm, chest of tightness, and shortness of breath were 35.8 %, 32.8 %, 23.4 %, and 22.4 %, respectively. significant differences between shortness of breath and work section (2=9.236, p=0.026) and %FEV1/FVC with work section [F (3, 3.98=3.194), p=0.025]. Smoking was associated with chronic cough (Adj OR =1.07, 95% CI: phlegm (Adj OR =1.05, 95% CI: 1.03 - 1.08), and shortness of breath (Adj OR = 1.05, 95% CI: 1.00 past respiratory illnesses was associated with chest tightness (Adj OR = 2.24, 95% CI: 1.04 - 4.84) and (Adj OR = 4.16, 95% CI: 1.92 - 9.92). Duration of employment was associated with FEV1 (β=-0.025, 0.020) while past respiratory illnesses was associated with %FEV1/FVC (β =-1.784, 95% CI: -3.017 workers are at risk of developing respiratory symptoms and lung function impairment.

Matched MeSH terms: Dust
Fulltext Monitoring of radionuclide contamination in food samples in Malaysia due to daiichi reactor accident in Fukushima, Japan

Nurrul Assyikeen Md. Jaffary, Wo, Yii Mei, Abdul Kadir Ishak, Noor Fadzilah Yusof, Kamarozaman Ishak, Maziah Mahmud, et al.

Jurnal Sains Nuklear Malaysia, 2015;27(1):14-20.
MyJurnal

On March 11, 2011, a serious accident occurred in Daiichi nuclear reactor plant, Fukushima,
Japan which caused radioactive materials been released into the atmosphere in the form of
aerosols and dust particles. Sea water around the plant was also found contaminated with high
radioactivity readings. These radioactive materials could be transported by the winds and ocean
current across international borders and cannot be controlled by human. Thus, a continuous
monitoring activity of radionuclide content in the air and sea water needs to be conducted by the
authorities. In addition to radioactivity monitoring, Malaysia should also control the entry of
contaminated food in order to prevent radionuclide ingestion by human. The radionuclide 131I,
134Cs and 137Cs were used as a measure of pollution levels and counted with gamma spectrometry
using standard analysis method suggested by AOAC International. In this paper, details description
of the role of Radiochemical and Environment Group, Nuclear Malaysia who’s responsible in
analyzing the radioactivity in the food samples due to Fukushima Daiichi, Japan accident was
included. The radioactivity limit adopted and analysis results from this monitoring were discussed

Matched MeSH terms: Dust
Fulltext Concentration of insecticides cypermethrin isomer in total suspended particulate in air of Cameron Highlands, Pahang, Malaysia

Norela Sulaiman, Toh LF, Hazzila Abdul Samat, Ismail Sahid, Maimon Abdullah, Mohd. Rozali Othman

Sains Malaysiana, 2007;36(2):91-95.

This study was carried out to determine the concentrations of cypermethrin in total suspended particulate in air in several farming areas of Cameron Highlands. Samples of total suspended particulate were collected using a high volume air sampler (Model Graseby) from six different sampling sites around Cameron Highlands. Laboratory analysis of total suspended particulate was conducted by the standard method. High dosages of cypermethrin were used by farmers in the dry season. Results of the study showed that the concentrations of cypermethrin in total suspended particulate in the air samples were higher during the dry season (May-July 2004) compared to the rainy season (September-October 2004). There was a significant positive correlation between the concentrations of cypermethrin and total suspended particulate (p<0.05).

Matched MeSH terms: Dust
Fulltext Endotoxin, ergosterol, fungal DNA and allergens in dust from schools in Johor Bahru, Malaysia- associations with asthma and respiratory infections in pupils

Norbäck D, Markowicz P, Cai GH, Hashim Z, Ali F, Zheng YW, et al.

PLoS One, 2014;9(2):e88303.
PMID: 24523884 DOI: 10.1371/journal.pone.0088303

There are few studies on associations between respiratory health and allergens, fungal and bacterial compounds in schools in tropical countries. The aim was to study associations between respiratory symptoms in pupils and ethnicity, chemical microbial markers, allergens and fungal DNA in settled dust in schools in Malaysia. Totally 462 pupils (96%) from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated. Dust was vacuumed from 32 classrooms and analysed for levels of different types of endotoxin as 3-hydroxy fatty acids (3-OH), muramic acid, ergosterol, allergens and five fungal DNA sequences. Multiple logistic regression was applied. Totally 13.1% pupils reported doctor's diagnosed asthma, 10.3% wheeze and 21.1% pollen or pet allergy. Indian and Chinese children had less atopy and asthma than Malay. Carbon dioxide levels were low (380-690 ppm). No cat (Fel d1), dog (Can f 1) or horse allergens (Ecu cx) were detected. The levels of Bloomia tropicalis (Blo t), house dust mite allergens (Der p 1, Der f 1, Der m 1) and cockroach allergens (Per a 1 and Bla g 1) were low. There were positive associations between levels of Aspergillus versicolor DNA and daytime breathlessness, between C14 3-OH and respiratory infections and between ergosterol and doctors diagnosed asthma. There were negative (protective) associations between levels of C10 3-OH and wheeze, between C16 3-OH and day time and night time breathlessness, between cockroach allergens and doctors diagnosed asthma. Moreover there were negative associations between amount of fine dust, total endotoxin (LPS) and respiratory infections. In conclusion, endotoxin at school seems to be mainly protective for respiratory illness but different types of endotoxin could have different effects. Fungal contamination measured as ergosterol and Aspergillus versicolor DNA can be risk factors for respiratory illness. The ethnical differences for atopy and asthma deserve further attention.

Matched MeSH terms: Dust
Endotoxin, ergosterol, muramic acid and fungal DNA in dust from schools in Johor Bahru, Malaysia--Associations with rhinitis and sick building syndrome (SBS) in junior high school students

Norbäck D, Hashim JH, Markowicz P, Cai GH, Hashim Z, Ali F, et al.

Sci Total Environ, 2016 Mar 1;545-546:95-103.
PMID: 26745297 DOI: 10.1016/j.scitotenv.2015.12.072

This paper studied associations between ocular symptoms, rhinitis, throat and dermal symptoms, headache and fatigue in students by ethnicity and in relation to exposure to chemical microbial markers and fungal DNA in vacuumed dust in schools in Malaysia. A total of 462 students from 8 randomly selected secondary schools in Johor Bahru, Malaysia, participated (96% response rate). Dust was vacuumed from 32 classrooms and analysed for levels of five types of endotoxin as 3-hydroxy fatty acids (C10, C12, C14, C16 and C18 3-OH), muramic acid, ergosterol and five sequences of fungal DNA. Multiple logistic regression was applied. Totally 11.9% reported weekly ocular symptoms, 18.8% rhinitis, 15.6% throat and 11.1% dermal symptoms, 20.6% headache and 22.1% tiredness. Totally 21.1% reported pollen or furry pet allergy (atopy) and 22.0% parental asthma or allergy. Chinese students had less headache than Malay and Indian had less rhinitis and less tiredness than Malay. Parental asthma/allergy was a risk factor for ocular (odds ratio=3.79) and rhinitis symptoms (OR=3.48). Atopy was a risk factor for throat symptoms (OR=2.66), headache (OR=2.13) and tiredness (OR=2.02). There were positive associations between amount of fine dust in the dust samples and ocular symptoms (p<0.001) and rhinitis (p=0.006). There were positive associations between C14 3-OH and rhinitis (p<0.001) and between C18 3-OH and dermal symptoms (p=0.007). There were negative (protective) associations between levels of total endotoxin (LPS) (p=0.004) and levels of ergosterol (p=0.03) and rhinitis and between C12 3-OH and throat symptoms (p=0.004). In conclusion, the amount of fine dust in the classroom was associated with rhinitis and other SBS symptoms and improved cleaning of the schools is important. Endotoxin in the school dust seems to be mainly protective for rhinitis and throat symptoms but different types of endotoxin could have different effects. The ethnic differences in symptoms among the students deserve further attention.

Matched MeSH terms: Dust
Fulltext Rhinitis, Ocular, Throat and Dermal Symptoms, Headache and Tiredness among Students in Schools from Johor Bahru, Malaysia: Associations with Fungal DNA and Mycotoxins in Classroom Dust

Norbäck D, Hashim JH, Cai GH, Hashim Z, Ali F, Bloom E, et al.

PLoS One, 2016;11(2):e0147996.
PMID: 26829324 DOI: 10.1371/journal.pone.0147996

There are few studies on rhinitis and sick building syndrome (SBS) among students in tropical countries. We studied associations between levels of five fungal DNA sequences, two mycotoxins (sterigmatocystin and verrucarol) and cat allergen (Fel d 1) levels in schools and rhinitis and other weekly SBS symptoms in the students. Fungal DNA was measured by quantitative PCR and cat allergen by ELISA. Pupils (N = 462) from eight randomly selected schools in Johor Bahru, Malaysia participated (96%). Dust samples were collected by cotton swabs and Petri dishes exposed for one week. None of the schools had a mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures and indoor CO2 levels were low (mean 492 ppm; range 380-690 ppm). Weekly nasal symptoms (rhinitis) (18.8%), ocular (11.6%), throat (11.1%), dermal symptoms, headache (20.6%) and tiredness (22.1%) were common. Total fungal DNA in swab samples was associated with rhinitis (p = 0.02), ocular symptoms (p = 0.009) and tiredness (p = 0.001). There were positive associations between Aspergillus versicolor DNA in Petri dish samples, ocular symptoms (p = 0.02) and tiredness (p = 0.001). The level of the mycotoxin verrucarol (produced by Stachybotrys chartarum) in swab samples was positively associated with tiredness (p = 0.04). Streptomyces DNA in swab samples (p = 0.03) and Petri dish samples (p = 0.03) were negatively associated with tiredness. In conclusion, total fungal contamination, measured as total fungal DNA) in the classrooms, Aspergillus versicolor and verrucarol can be risk factors for rhinitis and SBS symptoms among students in the tropical country Malaysia.

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 Effect of exposure to dust on lung function of cement factory workers

Noor H, Yap CL, Zolkepli O, Faridah M

Med J Malaysia, 2000 Mar;55(1):51-7.
PMID: 11072491 MyJurnal

Exposure to Portland cement dust has long been associated with the prevalence of respiratory symptoms and varying degrees of airway obstruction in man. Apart from respiratory diseases, it was also found to be the cause of lung and laryngeal cancer, gastrointestinal tumours and also dermatitis. This study was done to investigate the effect of dust exposure on ventilatory lung function of Portland cement factory workers in Rawang, Selangor. Spirometry tests of 62 male workers (exposed to total dust concentration of 10,180 micrograms/m3 and PM10 of 8049 micrograms/m3) and 70 subjects from UPM (exposed to mean total dust of 192 micrograms/m3 and PM10 of 177 micrograms/m3--controls) revealed significant differences in spirometry values between the groups. The workers showed i) significantly lower FEV1% and FEF25-75%, and higher FMFT, ii) reduced FEV1% with increasing level of dust exposure and iii) higher prevalence of respiratory symptoms. Therefore, we suggest that exposure to dust in the cement factory leads to higher incidence of respiratory symptoms and impaired lung function.

Matched MeSH terms: Dust*; Industry*
A study of the effectiveness of local exhaust ventilation (LEV) using computational fluid dynamics (CFD) approach

Ng, C. S., Leman, A. M., N. Asmuin

Journal of Occupational Safety and Health, 2012;9(3):1-8.
MyJurnal

Local exhaust ventilation (LEV) is used in industries to capture contaminants such as gases, dusts, mists, vapours or fumes out of workstations to protect occupants’ exposure to contaminants. LEV is allocated and installed by employers, however it doesn’t work accordingly. LEV design is often overlooked and underappreciated. Effectiveness of LEV system can be achieved if more attention is focused to proper design of LEV system. To solve this issue, computational fluid dynamics (CFD) can be performed. CFD is a software tool to predict and simulate fluid dynamic phenomena. CFD is used to forecast or reconstruct the behaviour of an engineering product under assumed or measure boundary conditions. However, CFD is just a prediction tool, which can lead to inaccuracy of predicting airflow due to problems with pre-processing, solver and post-processing with parameter from actual experimental results. Therefore, validation is needed to help minimizing percentage error of CFD methods. In this research, measurements of airflow parameter of LEV system at National Institute of Occupational Safety and Health (NIOSH) Bangi, Selangor were conducted. Control Speed panel found at NIOSH Bangi, which is used to increase or decrease speed of fan, was performed using Control Speed of 20%, 40% 60% and 80%. Upon validation, average absolute error obtained from four different control speeds ranges from 3.372% to 4.862%. Validity of CFD modelling is acceptable, which is less than 5% and good agreement is achieved between actual experimental results and CFD simulation results. Therefore, it can be concluded that CFD software tool can be performed to simulate air velocity in LEV system. CFD methods can save labour costs and time consumption when it is used during earliest stage of LEV design, before actual construction is implemented. The outcome of this paper can be used as a baseline for factories equipped with LEV system to protect occupants’ exposure to contaminants.

Matched MeSH terms: Dust; Industry
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
Asian dust increases radiocesium retention ability of serpentine soils in Japan

Nakao A, Tomita M, Wagai R, Tanaka R, Yanai J, Kosaki T

J Environ Radioact, 2019 Aug;204:86-94.
PMID: 30986719 DOI: 10.1016/j.jenvrad.2019.03.028

Radiocesium (RCs) is selectively adsorbed on interlayer sites of weathered micaceous minerals, which can reduce the mobility of RCs in soil. Therefore, soils developed from mica-deficient materials (e.g. serpentine soils) may have a higher risk of soil-to-plant transfer of RCs. Soils were collected from three serpentine soil profiles; Udepts in Oeyama, Japan, and Udepts and Udox in Kinabalu, Malaysia. Soil was sampled every 3 cm from 0 to 30 cm depth and sieved to isolate soil particles of ≤20 μm diameter for the assessment of radiocesium interception potential (RIP) after a series of pretreatments. One subset was treated with H2O2 to remove organic matter (OM). Another subset was further treated with hot sodium citrate to remove hydroxy-Al polymers (Al(OH)x). RIPuntreated was <0.4 mol kg-1 whereas mica-K content was <0.02% by weight for ≤20-μm soil particles from Udepts and Udox in Kinabalu, Malaysia, values as low as those of non-micaceous minerals (e.g. kaolinite and smectite). Neither OM nor Al(OH)x removal resulted in a large increase in RIP value for these soils. These results clearly indicated that serpentine soils in Malaysia have very few RCs selective adsorption sites due to the absence of micaceous minerals. In contrast, soil from Udepts in Oeyama, Japan showed average RIPuntreated of 5.6 mol kg-1 and mica-K content of 0.72% by weight for the ≤20-μm particles. Furthermore, the RIP value was significantly increased to an average of 22.5 mol kg-1 after removing both OM and Al(OH)x. These results strongly suggest that weathered micaceous minerals primarily control the ability to retain RCs. These micaceous minerals cannot originate from serpentine minerals, and are probably incorporated as an exotic material, such as Asian dust. This hypothesis is supported by the δ18O value of quartz isolated from the ≤20-μm soil particles from Oeyama, Japan (+16.13‰±0.11‰), very similar to that of Asian dust. In conclusion, serpentine soils in Japan may exhibit a reduced risk of soil-to-plant transfer of RCs due to the historical deposition of Asian dust.

Matched MeSH terms: Dust/analysis*
Corrosivity and leaching behavior of controlled low-strength material (CLSM) made using bottom ash and quarry dust

Naganathan S, Razak HA, Hamid SN

J Environ Manage, 2013 Oct 15;128:637-41.
PMID: 23845957 DOI: 10.1016/j.jenvman.2013.06.009

This paper reports the corrosivity and leaching behavior of CLSM made using two different industrial wastes i.e. bottom ash from an incineration facility and quarry dust. The leachate samples were derived from fresh and hardened CLSM mixtures, and studied for leaching and electrical resistivity. The release of various contaminants and the consequent environmental impact caused by the contaminants were studied by the measurement of contaminants in the bleed, in the leachate at 28 days, and on the leachate derived from crushed block and whole block leaching done over a period of 126 days. Results indicated that the CLSM mixtures are non corrosive; diffusion was the leaching mechanism; and the contaminants were found to be moderate to low mobility.

Matched MeSH terms: Dust; Industrial Waste*
Fulltext House dust mites, our intimate associates

Nadchatram M

Trop Biomed, 2005 Jun;22(1):23-37.
PMID: 16880751

House dust mites have lived in human contact from time immemorial. Human dander or dead skin constitutes the major organic component of the house dust ecosystem. Because the mites feed on dander, dust mites and human association will continue to co-exist as part of our environment. Efficient house-keeping practice is the best form of control to reduce infestation. However, special precautions are important when individuals are susceptible or sensitive to dust mites. House dust mites are responsible for causing asthma, rhinitis and contact dermatitis. The respiratory allergies are caused by the inhalation of dead or live mites, their faecal matter or other byproducts. Immune factors are of paramount importance in the development of dust related or mite induced respiratory diseases. House dust mites were found in some 1,000 samples of dust taken from approximately 330 dwellings in Peninsular Malaysia and Singapore. Mattresses, carpets, corners of a bedroom, and floor beneath the bed are favourable dust mite habitats. The incriminating species based on studies here and elsewhere, as well as many other species of dust mites of unknown etiological importance are widely distributed in Malaysian homes. Density of dust mites in Malaysia and Singapore is greater than in temperate countries. Prevention and control measures with reference to subjects sensitive to dust mite allergies, including chemical control described in studies conducted in Europe and America are discussed. However, a cost free and most practical way to remove mites, their faecal matter and other products is to resort to sunning the bedding and carpets to kill the living mites, and then beaten and brushed to remove the dust and other components.

Matched MeSH terms: Dust*
Fulltext An overview of industrial dust explosion incidents and the best mitigation practices in Malaysia

Mohd Azimie Ahmad, Norazura Ismail, Mohamad Rizza Othman

Journal of Occupational Safety and Health, 2015;12(1):179-182.
MyJurnal

The trends of safety incident process have been put in the statistical research and development in order to prevent
and mitigate the phenomenon. One of the incidents is known as dust explosion. It represents a constant hazard to
industries which includes any manufacturing using and handling combustible dust materials. Lack of sharing and
know-how on best practices in managing the workplace must be avoided throughout the industries. The severity and
the consequences of not taking the safety precautions at workplace have not been foreseen by the process team. This
present paper discusses the best practices in managing the hazards from the catastrophes to happen again. In addition,
the mitigation response has also been explored thoroughly through database of best practices.

Matched MeSH terms: Dust; Industry
Source apportionment and health risk assessment of PM10 in a naturally ventilated school in a tropical environment

Mohamad N, Latif MT, Khan MF

Ecotoxicol Environ Saf, 2016 Feb;124:351-362.
PMID: 26590697 DOI: 10.1016/j.ecoenv.2015.11.002

This study aimed to investigate the chemical composition and potential sources of PM10 as well as assess the potential health hazards it posed to school children. PM10 samples were taken from classrooms at a school in Kuala Lumpur's city centre (S1) and one in the suburban city of Putrajaya (S2) over a period of eight hours using a low volume sampler (LVS). The composition of the major ions and trace metals in PM10 were then analysed using ion chromatography (IC) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The results showed that the average PM10 concentration inside the classroom at the city centre school (82µg/m(3)) was higher than that from the suburban school (77µg/m(3)). Principal component analysis-absolute principal component scores (PCA-APCS) revealed that road dust was the major source of indoor PM10 at both school in the city centre (36%) and the suburban location (55%). The total hazard quotient (HQ) calculated, based on the formula suggested by the United States Environmental Protection Agency (USEPA), was found to be slightly higher than the acceptable level of 1, indicating that inhalation exposure to particle-bound non-carcinogenic metals of PM10, particularly Cr exposure by children and adults occupying the school environment, was far from negligible.

Matched MeSH terms: Dust/analysis

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