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Received: December 2014, Accepted: April 2015 Background: Work-related musculoskeletal disorders (WRMSDs) are considered a major factor in health problems, human injuries, and loss of work time. The aim of the present study was to assess the risk of musculoskeletal disorder (MSD) and evaluate the prevalence of MSD among female hairdressers. Materials and Methods: In this descriptive analytical study, the risk of MSDs was evaluated in 172 female hairdressers using the Rapid Entire Body Assessment (REBA) method. Moreover, the prevalence of WRMSDs was investigated using a Nordic questionnaire. All obtained data was analyzed by means of SPSS software, and the logistic regression model. Results:The results showed that 58.7% of the hairdressers experienced pain in their lower back, 52.3% in their neck, 41.3% in their knees, and 20.3% in their ankle. The results of this study showed a significant correlation between BMI and MSDs in the elbow, hip, and thigh. The results of REBA indicate that about 46% of the 1032 postures were classified as high risk and about 14.9% as very high risk. In addition, the results of this study showed a significant correlation between REBA score and MSDs in the neck, wrist, hip, and thigh. Conclusions: With regard to the high prevalence of symptoms in the waist, neck, and wrist, it can be concluded that prolonged standing, uncomfortable working postures, strenuous movements, excessive shoulder flexion and shoulder abduction, trunk flexion and forceful exertion, and repetitive motion are considered important risk factors for MSDs.

In this study, the potential of hexadecyl trimethyl ammonium bromide modified montmorillonite (HDTMA-Mt) to remove the synthetic dyes Alizarin Red S (ARS) and Bromocresol Green (BCG) from aqueous media was assessed. The effect of different factors including surfactant loading rate onto the clay, contact time, pH, adsorbent dosage and dye concentrations, on the removal of ARS and BCG in batch systems were investigated. The adsorbent was characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). The equilibrium time for ARS and BCG was reached at 40 and 20 min, respectively, under optimized conditions (i.e. pH = 3, adsorbent dosage=1 g/L, surfactant loading rate onto the clay 70% of the cation exchange capacity (CEC) for ARS and 120% of the CEC for BCG, ARS concentration 50 mg/L and BCG concentration 500 mg/L). The adsorption rate of both dyes fitted the pseudo-second-order kinetic model and the equilibrium data was described by the Freundlich isotherm equation. The maximum monolayer adsorption capacities were equal to 666.6 and 1250 mg/g for ARS and BCG, respectively. Therefore, the HDTMA-Mt can be considered as an effective adsorbent for the removal of ARS and BCG from aqueous solutions.

This study was conducted to quantify, by an approach proposed by the World Health Organization (WHO), the daily hospital admissions for chronic obstructive pulmonary disease (COPD) related to exposure to particulate matter (PM) and oxidants such as ozone (O), sulfur dioxide (SO), and nitrogen dioxide (NO) in a heavily polluted city in Iran. For the health impact assessment, in terms of COPD, the current published relative risk (RR) and baseline incidence (BI) values, suggested by the WHO, and the 1-h O concentrations and daily PM, NO, and SO concentrations were compiled. The results showed that 5.9, 4.1, 1.2, and 1.9% of the COPD daily hospitalizations in 2011 and 6.6, 1.9, 2.3, and 2.1% in 2012 were attributed to PM, O, SO, and NO concentrations exceeding 10 μg/m, respectively. This study indicates that air quality and the high air pollutant levels have an effect on COPD morbidity. Air pollution is associated with visits to emergency services and hospital admissions. A lower relative risk can be achieved if some stringent control strategies for reducing air pollutants or emission precursors are implemented.

The use of natural biodegradable fibers in manufacturing of porous sound absorbers is an environmental-friendly approach employed by many researchers in the field of noise control and acoustics. The present study aimed to determine and compare the sound absorption coefficients of samples fabricated from fibers of coir and date palm by experimental and analytical methods. Experimental measurements of the sound absorption coefficients were performed in an impedance tube by modifying several parameters (thickness and air gap) of the samples. Prediction of sound absorption coefficient was determined by Delany-Bazley, Miki and Johnson-Champoux-Allard models along with differential evolution algorithm in MATLAB software and data from the experiments. The correlation between the sound absorption coefficients obtained from the experiments and the ones predicted by the existing models was examined by the Pearson correlation test. Samples from both type of fibers showed a poor and almost similar sound absorption in low-frequency range. In intermediate range (1000-3000 Hz), the sound absorption significantly increased to the maximum levels of 0.81 and 0.84 at 2000 Hz for the thickness of 40 mm. An increase in the samples thickness led to a fair agreement between values of sound absorption coefficient obtained from experimental and analytical methods. Correlation analysis showed that there was a significant and strong correlation between the outputs from the existing models and the experiments. The values approximated by Johnson-Champoux-Allard model demonstrated a better fit with the ones determined by the experimental tests.