RESUMO
In this research work, a synthetic water super absorbent polymer was included in the bed of a perlite-based biofilter for the removal of ethanol from air. The performance of this biofilter was compared with the performance of a control perlite-based biofilter lacking the water super absorbent. With the empty bed residence time of 2â min, both biofilters were able to remove more than 90% of the entering pollutant with the concentration of 1â gâ /m3, when regular moistening was applied. After last irrigation on day 23, the performance of the control biofilter was unchanged until day 35. From day 36 onwards, the control biofilter lost its activity gradually and became totally inactive on day 45. The performance of the super absorbent containing biofilter, however, was unchanged until day 58 before starting to lose its activity. A mechanistic model was developed to describe the performance of a biofilter under drying effects. The model could predict the trends of experimental results reasonably well. The model was also applied to predict the trends of experimental data from a published paper on the removal of hexane in a perlite/super absorbent containing biofilter.
Assuntos
Fenômenos Fisiológicos Bacterianos , Etanol/isolamento & purificação , Membranas Artificiais , Modelos Biológicos , Polímeros/química , Ultrafiltração/instrumentação , Adsorção , Biodegradação Ambiental , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Etanol/química , Resíduos Industriais/prevenção & controleRESUMO
Genetic factors have an important role in the incidence of osteopenia in thalassemia patients. The purpose of this study was to investigate the effect of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-γ (PPARγ) gene on bone mineral density (BMD) and subsequently, the rate of osteopenia in ß-thalassemia major (ß-TM) patients. Blood samples were obtained from 156 ß-TM patients referred to the Tehran and Qazvin Thalassemia Clinics. Samples were analyzed for polymorphisms of the PPARγ gene using polymerase chain reaction-restriction fragment length polymorphism (RFLP)-based methods. Multivariate analysis was used to investigate the relationship between the risk of osteopenia and the PPARγ gene polymorphism. Correlation analysis showed that there was a significant association between homozygous wild-type genotypes with susceptibility to osteopenia in ß-TM patients (p = 0.024). Logistic regression analysis showed that the risk of osteopenia was significantly (p <0.05) higher in the homozygous wild-type genotype than carriers of the rare alleles. Furthermore, the associations were strengthened in men with a homozygous wild-type genotype after adjustment for age and body mass index (BMI) (p <0.05). This study suggests that the Pro12Ala polymorphism of the PPARγ gene might be an independent factor in BMD level and osteopenia in thalassemia patients.
Assuntos
Doenças Ósseas Metabólicas/etiologia , PPAR gama/genética , Polimorfismo de Nucleotídeo Único , Talassemia beta/complicações , Talassemia beta/genética , Adulto , Alelos , Substituição de Aminoácidos , Densidade Óssea , Doenças Ósseas Metabólicas/diagnóstico , Códon , Estudos Transversais , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Fatores de Risco , Fatores Sexuais , Adulto JovemRESUMO
BACKGROUND: In developing countries, construction is a largely manual job that imposes awkward postures on workers, thus facilitating a variety of musculoskeletal disorders. Ergonomic training is known as an effective way to reduce these disorders. OBJECTIVE: This study aimed to evaluate the effectiveness of ergonomic training intervention in reducing the ergonomic risk of concrete form workers. METHODS: This quasi-experimental study was carried out on 144 concrete form workers employed in the construction projects of Gonbad-e Kavus, Iran, Iran. Data was collected using the Nordic Musculoskeletal Questionnaire (at the pre-intervention stage) and the Rapid Entire Body Assessment (REBA) worksheet (at the pre- and post-intervention stages). Ergonomic training was provided via face-to-face educational meetings along with presenting informative pamphlets, which took place over 45 days duration of time. Data were analyzed by the use of SPSS software version 21, t-test and Wilcoxon test. Significant level was considered at P-value less than 0.05. RESULTS: Musculoskeletal disorders were observed in all limbs of the studied workers. The most prevalent disorders were the pain in the shoulder region of lift operators (86.1%) and the pain in the back area of mixer operators (77.8%). About 99.3% of all concrete form workers were exposed to a moderate level of ergonomic risk and needed posture correction. Pre- and post-training REBA scores showed a statistically significant difference (Pâ<â0.05). CONCLUSION: Although the ergonomic training did reduce the ergonomic risk of workers, because of its short duration, it failed to reduce this risk to an acceptable level. It is recommended to hold both theoretical and practical training sessions over longer periods of time.
Assuntos
Doenças Musculoesqueléticas , Doenças Profissionais , Ergonomia , Humanos , Irã (Geográfico) , Doenças Musculoesqueléticas/prevenção & controle , Doenças Profissionais/prevenção & controle , PosturaRESUMO
BACKGROUND: Dust exposure at quarry mines is inevitable and can result in poor air quality. This research aimed to assess pulmonary symptoms and lung functions of dust-exposed workers at an iron-ore mine in eastern Iran. METHODS: An environmental cross-sectional study sampled 174 dust-exposed mine workers and 93 unexposed administrative employees as the reference group. A standardized questionnaire on respiratory symptoms was completed in accordance with recommendations of the American Thoracic Society(ATS). Calibrated spirometer measured Pulmonary Function Tests (PFTs). Data were analyzed via SPSS-21, integrating independent samples t-test, Chi-square and linear or logistic-regression models. RESULTS: There was no significant variation between dust-exposed and reference groups in terms of age, weight, height, work experience and the number of smokers (P>0.05). Mean levels of exposure to inhalable and respirable mineral-dust were 15.09±2.34 and 3.45±2.57 mg/m3 respectively. Pulmonary capacities of dust-exposed group were considerably decreased as compared to others (Forced Vital Capacity [FVC] 86.55±13.77 vs. 105.05±21.5; Forced Expiratory Volume in 1 second [FEV1] 88.06±16.8 vs. 105.81±21.55; FEV1/FVC 103.03±18.17 vs. 93.3±12.49; and Peak Expiratory Flow [PEF] 89.82±22.58 vs. 98.09±20.60) (P<0.001); with a higher prevalence of cough (P=0.041), wheezing (P=0.032), and dyspnea (P=0.035) among formers. Age along with exposure to respirable-dust significantly reduced FVC, FEV1 and FEV1/FVC. Cigarette consumption attenuated FVC and FEV1 on an average of 5 to 9 units. CONCLUSION: Controlled occupational dust-exposure is a definitive pre-requisite to reduce respiratory problems among quarry workers, with an explicit consideration towards mineral- mine workers. Modifiable accomplices like smoking and non-compliance of PPEs usage should be amicably resolved.
RESUMO
Green synthesis is a novel method for nanoparticle preparation, which is known as an environmentally friendly technique (Wang et al., 2017a, 2017b) [1], [2]. This research was carried out to investigate the use and efficacy of Barberry leaf, Elaeagnus angustifolia leaf, Saffron sepal, and Ziziphus jujube leaf extracts as agents for the synthesis of green iron nanoparticles (GINPs). The studied plants are among the native plants abundantly found in South Khorasan, Iran. The data also show the effect and role of important variables in green synthesis process including Fe to extract ratio, extract heating time, and length of time when Fe-extract solution was mixed under ultrasonic waves. The effects of the mentioned variables were measured by weighing the produced nanoparticle and determining the yield of the prepared nanoparticles. Based on the data, with decreasing Fe to extract ratio, the amount of produced GINPs was increased but the yield of the process decreased. Additionally, extract heating time and ultrasonic mixing time had a significant effect on GINPs yield. Based on the results of transmission electron microscopy (TEM) test, the size of GINPs in all of the plant extracts was about 40â¯nm and smaller.
RESUMO
Dust can be produced by almost all production processes in Portland cement factory. Dust exposure potentially can affect respiratory function. But evidence for respiratory effect of cement dust exposure has not been conclusive. In this study we assessed effect of cement dust exposure on respiratory function in a cement production factory. A respiratory symptoms questionnaire was completed and pulmonary function tests were carried out on 94 exposed and 54 non exposed workers at a cement factory in the east of Iran. Additionally, respirable dust level was determined by the gravimetric method. X-ray fluorescence (XRF) technique was performed to determine the silica phases and the SiO(2) contents of the bulk samples. The arithmetic means (AM) of personal respirable dust were 30.18 mg/m(3) in the crushing, 27 mg/m(3) in the packing, 5.4 mg/m(3) in the cement mill, 5.9 mg/m(3) in the kiln and 5.48 mg/m(3) in the maintenance that were higher than threshold limit value (TLV) of the American Conference of Governmental Industrial Hygienists (ACGIH) which is 5 mg/m(3). This value in the unexposed group was 0.93 mg/m(3). In this study cough, sputum, wheezing and dyspnea were more prevalent among exposed subjects. Exposed workers compared to the unexposed group showed significant reduction in Forced Expiratory Volume in one second (FEV(1)), Forced Vital Capacity (FVC), and Forced Expiratory Flow between 25% and 75% of the FVC (FEF(25-75%)) (P<0.05). It can be concluded that in our study there was close and direct association between cement dust exposure and functional impairment among the cement factory workers.