مجله تحقیقات سلامت در جامعه
سال دوم شماره 2 (تابستان 1395)

Introduction and Exposure to natural sources of radiation¡ especially radon and its short-term products¡ is an important issue around the world. Radon exposure causes lung cancer in humans. Therefore¡ the aim of this study was to measure the concentration of radon gas and its annual effective dose in Imam Hospital of Tehran¡ Iran and to compare its concentrations with the recommended standards.
Radon levels and meteorological parameters (temperature¡ pressure¡ and moisture) were measured in different levels and in four seasons¡ using Radstar and Lutron Electronic devices¡ respectively¡ during June 2014-June 2015. The collected data were analyzed through SPSS 18. Annual effective dose was calculated¡ using the equation for annual effective dose introduced by Scientific Committee of the United Nations.
The highest concentration of radon and annual effective dose were observed in the winter¡ which were 82/15 Bq/m3 and0/48 ms/y¡ respectively. Furthermore¡ concerning the various levels¡ the highest concentration was observed in the lowest level (56/1 Bq/m3).
The results of the current study demonstrated that radon concentration was lower than the standards set by Environmental Protection Agency and World Health Organization. Regarding this¡ there are not concerns about the possible dangers of radon gas activities for the personnel and patients of the hospital.

Introduction and Industrial accidents are highly prevalent. Regarding this, identification of the risk factors of occupational accidents can be helpful in preventing the occurrence of this type of accidents. The aim of this study was to assess the risk factors in the incidence of occupational accidents and prioritize the severity of the identified risks in order to prevent their occurrence.
The current study utilized failure mode effects analysis (FMEA) method to evaluate the potential risk factors. All the units of Educational Equipment Manufacturers Company, including 12 different workstations with 55 employees, were assessed; furthermore, failure modes and effects as well as the causes of the failure of each component were recorded. Subsequently, Risk Priority Number (RPN) of each workstation was separately calculated and the crisis level of each risk was prioritized.
According to the results of the study, a variety of 51 risk factors were identified among 12 different workstations at the factory. It was demonstrated that 4.25%, 9.54%, and 6.19% of these risk factors were within acceptable, unacceptable, and emergency level, respectively. The highest risk frequency was related to the electric shock caused by working on guillotine, cutter, bending machine, and drilling press. However, the crisis level of these risk factors were found to be average owing to the decrease in the occurrence of these risk factors which was the result of control measures.
This study revealed a direct relationship between RPN and the frequency of occupational accidents. Because of the high risks of the aforementioned machines, plant workers are highly prone to occupational accidents and injuries. Although FMEA method is a functional approach in determining the risks of occupational accidents, it is also recommended to use process hazard analysis in order to have a more precise and comprehensive assessment.

Introduction and Soil contamination by petroleum is mostly resulted from oil exploration, refining processes, leaking of oil products from storage tanks, leaking from pipelines due to pipe friction and decay, refinery wastewater discharge and agricultural irrigation with such materials. Sodium persulfate (Na2S2O8), which is a chemical oxidant, could be activated in the presence of ferrous (Fe2) and, leading to the treatment of a wide range of soil contaminants. Therefore, this study aimed to evaluate the removal of hydrocarbons from soil media using persulfate oxidation in the presence of mineral siderite.
Initially, oil-contaminated soil was prepared in the form of two separate samples, including silt-clay and sandy-loam soils, which were orderly spiked with 5000 mg fuel oil per kilogram of dry soil. Following that, the effects of various factors, such as different concentrations of persulfate (100-500 mmol/L) and siderite (0.1-0.5 g/L), pH (3-9) and temperature (20-60◦C) and the removal of petroleum hydrocarbon were assessed.
In this study, the optimum condition for degeneration of total petroleum hydrocarbon in silt-clay soils was reported, as follows: temperature: 60◦C, pH: 3, and persulfate/siderite molar ratio of 400 mmol/L to 4.0 g/L. Meanwhile, the optimum condition for the removal of hydrocarbon from sandy-loam soils was pH: 3, temperature: 60◦C and persulfate/siderite molar ratio of 300 mmol/L to 3.0 g/L.
According to the results of this study, the optimal amount of persulfate and siderite could be used to remove hydrocarbons from contaminated soils.

Introduction and Work fatigue is one of the main causes of workrelated musculoskeletal disorders and reduced productivity in industry. Therefore, it is vital to evaluate work fatigue, especially muscle fatigue, to determine the permissible workload. This study aimed to evaluate muscle fatigue of brick field workers.
This cross-sectional study was conducted on transportation sector workers in Pey Dezh Brick Production Company, Golestan, Iran in 2015. In this research, the qualitative of Muscle Fatigue Assessment (MFA) method was used to assess the level of fatigue. Duration of each task and frequency of efforts were determined using the level of effort to obtain a numerical result for comparison with the standard level.
The evaluated task was to remove paired bricks from the conveyor and transfer them to trailer truck by workers. The final results revealed that lower back tolerated the most amount of pressure (score=323), followed by the shoulders and wrist of the right hand (scores=313), which were assigned to the fatigue level. Therefore, the highest total fatigue of workload was imposed on these body parts.
According to the results of this study, the upper limbs of workers incurred the highest burden in lifting bricks, and there was a in risk of WMSDS due to high workload. Therefore, it is recommended that working systems be improved through rotating work and reducing the number of transferred bricks to avoid risks caused by accumulation of fatigue.

Introduction and Air pollution is an important risk factor for the environment and public health, associated with increased severity of respiratory diseases. This study aimed to evaluate the association between various air pollutants and number of cases with severe acute respiratory syndrome referred to emergency medical centers in Tehran, Iran in 2013.
In this ecological study, the relationship between air pollution and acute respiratory symptoms in patients referred to the emergency centers of Tehran in 2013 was assessed. In total, 36787 patients with acute respiratory symptoms has been registered in these centers. Data on the number of cases with acute respiratory symptoms and air pollutants of emergency centers and air quality monitoring stations were collected. Moreover, Poisson regression was used to assess the relationship between air pollutant concentrations (PM2.5, SO2, NO2, O3, CO) and the number of cases with severe acute respiratory syndrome.
The results of the current study demonstrated that CO (weekly average IRR=1.1) and SO2 (three days average IRR=1.03 and weekly average IRR= 1.04) increased the risk of respiratory diseases 10%, 3%, and 4%, respectively. Consequently, longer duration of pollutants would increase the risk of respiratory syndromes.
According to the results of this study, increased air pollutant concentrations could be associated with escalated number of patients with acute respiratory symptoms referred to the emergency medical centers in Tehran.