Iranian Journal of health, safety andenvironment

1017-1026

Authors: Hossein Shahbazi, Vahid Hosseini, Yousef Rashidi, Parya Broomandi

A new analytical air pollution modeling system is introduced in this paper to estimate concentrations of primary and secondary air pollutants and using it for further studies in order to improve the knowledge of pollutants emission and dispersion over Tehran, and developing a decision support system. For this purpose, WRF/CAMx modeling system was used to simulate the gas-phase pollutants concentrations including primary and secondary pollutants, over Tehran during a wintertime episode, which is characterized by very high concentrations of pollutants. Pollutants were triggered by meteorological conditions leading to a forced holiday imposed on citywide operations to protect the health of citizens. Based on calculated Values of NMB error, WRF performs acceptable in predicting temperature and wind speed. Generally, time series plots show that WRF performs acceptable in mild selected episode. Also, the daily trends of pollutant concentrations are greatly affected by changes in local meteorological conditions such as planetary boundary layer (PBL) height, temperature, wind, and relative humidity over the Tehran area. An underestimation in prediction of all pollutants concentrations episode at Poonak and Aghdasyeh sites show due to the insufficient emission data at the site position used for the simulation were seen. Results showed that WRF/CAMx modeling system proved to be a useful tool for analyzing urban environmental problems, investigating the impact of air quality control policies, and predicting critical conditions. However, there were weaknesses in input data and modeling system calibration that should be improved before using the system for further studies.

1035-1040

Authors: Zahra Godarzvand Chegini, Amir Hossaain Javid, Amir Hesam Hassani

The application of biological treatment has been promising in recent years for the main advantage of biological treatment in COD and dye removal. The novelty of this study is capabilities of integrated fixed film system (IFAS) with a different arrangement of media to removal the dye and COD. The experiments were done with a survey of variables like SRT, MLSS/MLVSS, the initial concentration of dye and COD. In order to analyze data was used the first and second-order models. The result showed that the IFAS was effective even at high concentration of the dye (200mg L-1). COD reduction and dye removal efficiency were higher than 70% and 88-95%, respectively. For the biological treatment, an increase in SRT to 48hr. increased the dye and COD concentration reduction. Kinetics of COD reduction and dye removal was fitted with the second-order reaction by coefficient correlation of 0.95 and 0.97, respectively. Finally, the integration of fixed film media into the biological reactors affected performances of the system for decolorization from colored wastewater.

1051-1057

Authors: Mahdi Jalali, Sajjad Farhadi, Seyyed Ali Moussavi Najarkola, Sayyed Amir Reza Negahban, Razzagh Rahimpour, Ghasem Hesam, Hassan Mohammadpour

Occupational exposure to heat stress in casting and smelting industries can cause adverse health effects on employees who working in such industries. The present study was set to assess the correlation and agreement of heat stress indices, including wet bulb globe temperature (WBGT), and thermal work limit (TWL), and the deep body temperature indices in workers of several casting and smelting industries located in the vicinity of Tehran, Iran. In This cross-sectional study 40 workers randomly selected and were examined. WBGT and TWL were the indices used for assessing heat stress, and the tympanic temperature and the oral temperature were measured as the heat strain indices. The correlation and agreement of indices were measured using SPSS vs.16. The results of the assessment of WBGT, TWL, the tympanic temperature, and oral temperature showed that 80, 17.5, 40, and 32.5 percent of workers exposed to heat stress higher than permissible limits proposed by standard bodies. Moreover, the present study showed that the significant correlation coefficient between heat stress and heat strain indices was in the range of 0.844- 0.869. Further, there was observed a good agreement between TWL and heat strain indices. The agreement between TWL and the oral temperature was 0.63 (P-value≤ 0.001) and between TWL and tympanic temperature was 0.612 (P-value≤ 0.001). However, the agreement between WBGT and heat strain indices was not satisfactory. These values were 0.154 (P-value ≥ 0.068) and 0.215 (P-value≥ 0.028) for the oral temperature and the tympanic temperature, respectively. The TWL index had a better agreement than WBGT with heat strain indices so TWL index is the better choice for assessing the heat stress in casting and metal smelting industries.

1066-1071

Authors: Jafar Akbari, Shahram Safari, Meghdad Kazemi, Heshmatollah Nourmoradi, Behzad Mahaki, Habibollah Dehghan

Many studies have reported that exposure to workplace noise leads to increase in blood pressure. The aim of this study was to investigate the effect of hearing protection devices (HPDs) including ear plug and ear muff on the systolic and diastolic blood pressures of workers exposed to workplace noise in a textile industry. A total of 120 male workers that exposed to 95 dB noise were investigated in this study. The systolic and diastolic blood pressures of the workers were measured for three situations of earplug, earmuff and earplug along earmuff applications. Data analyses were conducted through SPSS software (version 20) and statistical tests of ANOVA and Independent Sample Tests. The comparison of mean blood pressure in three situations showed that using ear muff had a significant effect on the systolic and diastolic blood pressures in the workers. Furthermore, the use of ear plug only had an effect on the systolic blood pressure. But, the application of ear muff caused to decrease in the systolic and diastolic blood pressures only in the third stage of the study. With regard to the results in this study, in order to control the blood pressure changes of the workers, it is recommended to use ear muff in the textile industry.

1077-1081

Authors: Ayoub Ghanbary Sartang, Mehdi Ashnagar, Ehsanollah Habibi, Saeid Sadeghi

Shift work has been recognized as an important tool for organizing of work in developing countries. The disturbed depression, stress accident are the most common health‐related effects of shift work. The military personnel shift worker during work, are exposed to stress and psychological pressure that certainly affect the efficiency of their work. The aim of this study was to Investigation Effect of shift work on job burnout and Depression, Anxiety, Stress Scale in military personnel. This cross-sectional study was carried out on 100 military personnel male in Southern Iran. Respondents were divided into two groups based on their working schedule (50 shift work personnel / 50 day work personnel). Data collection tools were a Depression, Anxiety, and Stress Scale (DASS-21), demographic characteristics and Maslach job burnout questionnaire. Convenience sampling was used as sampling method. Finally, Data analysis was performed with SPSS (version 20), descriptive statistics, One Way Anova test, ANCOVA and t-independent test. The results of showed that shift work has an impact on burnout and DASS-21 and mean obtained score for DASS-21 and job burnout in shift workers are more day work individuals. Analysis of variance test showed significant difference between job burnout in day workers and shift workers and job burnout were more in shift workers. Also significant difference between DASS-21 in day workers and shift workers and DASS-21 was more in shift workers. This study showed that shift work has an impact on burnout and scale DASS-21 shall is taken to Intervention actions in shift works.