مجله مهندسی بهداشت حرفه ای
سال ششم شماره 4 (زمستان 1398)

Although Boilover occurs with a low frequency, but in case of occurrence, it can cause severe damage to people and equipment around the tank. The prediction of the fireball of Boilover phenomenon has an important role to play in adopting appropriate strategies for fire suppression of the atmospheric storage tank. The purpose of this study is to predict the consequence of fireball caused by Boilover phenomenon using empirical models.

This is a descriptive-analytic study. At first, empirical models presented for prediction of the Boilover consequence were identified. Then, the models used to predict the fireball geometry and its radiation heat flux around the tank. The results of model predictions were compared with the data of a small-scale experimental study and a large-scale real Boilover accident.

According to the results, the error of the INERIS and Buang model for predictions of radiation heat flux around the experimental Boilover were 23 and 31%, respectively. The error of these two models predictions of radiation heat flux of accident were 52% and 71%, respectively.

The INERIS and Buang models showed a lower error for prediction of the Boilover fireball consequences compared to other models. The results of this study can be used to assess the risk of Boilover in atmospheric storage tanks and help accident commander’s decision on strategies and tactics for the fire suppression of atmospheric storage tanks.

One of the main consequences of incident events in today's industries, especially those associated with the quantity and range of chemicals, is the widespread environmental degradation. Therefore, identifying effective factors in the formation of incidents and analyzing the complex and interrelationship between them is an important and important topic in accident analysis and a way of preventing them from occurring.

 This is a descriptive-analytic study that was conducted with the aim of analyzing the environmental events occurring in the MAPNA group. The main tool for the analysis of selected environmental incidents was the Tripot Beta technique, which identified the causes of events at three levels: obvious causes, pre-conditions and hidden causes.

For the 96 accidents analyzed, 533 pre-conditions and 1592 hidden causes were identified. Of all the hidden causes, the subject of repair and maintenance management has been the highest repetition. Also, among identified causes, the most important cause of inadequate specifications and requirements related to tools or equipment.

Emphasis on the correction of hidden causes, taking into account the lifecycle of the system, and focusing on promoting the level of safety in the design phase, as well as the importance of adopting appropriate risk-based maintenance and repair strategies, were the main suggestions of the present study

To investigate the effect of ergonomic environment of the work environment on the job satisfaction of the personnel employed in the projects of Iranian Gas Engineering and Development Company.

The present study is a descriptive-correlational research that was conducted by survey method. This research is also applied in terms of purpose. The statistical population of the study consisted of all staff members of Iran Gas Development Engineering Company in Tehran, which was 430 people and 205 people were selected according to Cochran formula. The data collection tool was Minnesota's standard job satisfaction questionnaire and a researcher-made questionnaire for measuring work environment (ergonomics). Descriptive statistics and inferential statistics (correlation and regression analysis between two variables) were used to analyze the data. Data were analyzed using SPSS software and software.

The findings of the study showed that the path coefficient between ergonomic variables with job satisfaction variable (0.46 at level P <0.001) is. As well as ergonomic variables, 21% of variable variance explains job satisfaction

Regression between ergonomic variable and job satisfaction variable is positive and significant. Pearson correlation between these two variables is also moderate and significant.

Sustainable development is human-centered and deserves health and safety. The rapid growth of industrialization, coupled with insufficient attention to safety principles, has led to an increase in the rate of accidents in developing countries. The purpose of this study was to estimate the years of life lost due to work-related accidents among workers covered by the National Social Security Organization from 2007 to 2017.

This is a descriptive cross-sectional study and was carried out on the statistics of accidents related to the work of the Social Security Organization using the Dali index. Disability percentiles were used to estimate disability burden. The number of years lost due to early death (YLL) and years lost due to disability (YLD) and Disability-Adjusted Life Years (DALY) were calculated using Excel software.

The results showed that the number of years lost (DALY) due to work accidents is 181900 years, with 15.8% share of the number of years lost due to early death and 84.2% share of years lost due to disability. Most of the years lost due to work-related accidents are related to construction activities with 39860 years (21.9%).

The results of this study highlight the inadequate supervision of construction activities and the need for early training in construction workers and contractors.
Keywords: DALY, work-related accidents, Social Security Organization, Years of Life Lost, Death, Disability

Today, work-family issues have gained special importance for employees, families, and organizations.  Work–family conflict is an inter-role conflict in which work and family demands are mutually incompatible and creates stress and numerous problems. So, the aim of this present study was to examine the effectiveness of work- family conflict management training on work- life quality.

In a pretest- posttest quasi- experimental research design with control group, a total of 30 female employees in hospital of Nourabad selected via voluntary sampling method and accidently divided into experimental group and control group. The experimental group was undergone six-session format of work- family conflict management program. Data was collected using Quality of work- life questionnaire (QWLQ) and were analyzed using covariance analysis.

The results of covariance analysis showed that the training of work-family conflict management skills is effective on enhancing the work-life quality of employees, in that way by  after adjusting pre-test scores, there was a significant difference between the post-test scores of the two experimental and control groups (P <0.01).

So, according to the finding of this study can be concluded that the use of work-family conflict management skills helps female hospital staff to better cope with the inevitable problems and stresses of work-family conflict and as a result, the quality of their working life will increase.

Operators of construction vehicles are constantly exposed to whole body vibration, which can lead to musculoskeletal disorders. The aim of present study was to evaluate the impact of exposure to whole body vibration in operators and its relation to musculoskeletal disorders. This study is a descriptive-analytical study. Using easy sampling, 89 operators from 6 types of heavy vehicles (Bulldozer, Tipper Truck, Heavy Vibrator Roller, Light Vibrator Roller, Pecker and Loader) were included in two construction projects. To evaluate exposure to whole body vibration, different vibration indices (effective acceleration, peak factor and vibrational dose) were measured according to ISO 2631 and SVAN 958 vibrometer. The Body Map Questionnaire was used to assess the musculoskeletal disorders. Data were analyzed using Kolmogorov-Smirnov tests, one-way ANOVA, Pearson correlation and multivariate regression (significance level less than 0.05). The results of this study showed that exposure to whole body vibration in Bulldozer (2.25 m/s2), Tipper Truck (0.98 m/s2), Heavy Vibration Rollers (3.20 m/s2), Light Vibration Rollers (3.45 m/s2) Pecker (4.11 m/s2) and Loader (1.2 m/s2) are more than the daily exposure to OEL. There was a significant and direct relationship between exposure to vibration, underlying factors and musculoskeletal disorders. The present study confirms the potential health hazards for operators of construction vehicles. Therefore, engineering and management controls are recommended, including installation of appropriate vibration insulators on seats, training courses, changing jobs of individuals with a long exposure to vibration, rotating work schedules, using gloves, flooring and vibration damping pads and create monitoring protocols on work.

Supplier selection plays a significant role in sustainable supply chain management. Current studies have mainly concentrated on economic factors for the selection and evaluation of suppliers, and few emphasis has been made on the triple factors of sustainability including economic, environmental and social elements. Improving Health, Safety and Environment (HSE) performance levels promotes corporate sustainability in two social (social responsibility) and environmental dimensions. Thus, in this research, a framework is presented to evaluate HSE performance of suppliers and rank them accordingly.

Upon reviewing the literature and obtaining expert opinions, HSE performance evaluation criteria were determined. Then, with a simultaneous use of Multi-Criteria Decision Making (MCDM) techniques the suppliers were ranked. To determine the HSE performance criteria and indicators, resilience engineering approach was used, which is a novel approach relative to the traditional safety management approaches. Four grade A Iranian auto parts manufacturers as the suppliers of automobile industry were selected as the case study.

Of the determined criteria, “management commitment”, and from amongst the final indicators, "allocation of sufficient budget for HSE measures” achieved the highest weight, and eventually the best supplier was selected on this basis.

Since the decision making managers of suppliers were involved in determining and weighting the criteria, the developed model of this study can be practically applied in supplier evaluation processes. This, in turn, can encourage suppliers to improve the occupational health and safety of their employees and apply green strategies in production policies.

Due to the increasing use of chemicals in academic laboratories, a tool to measure awareness of students regarding labeling, hazards and characteristics of chemicals is still needed. The aim of  this study was to design and validate a questionnaire to the assessing student’s knowledge about chemical hazards. The present study was conducted in two stages of design and evaluation of validity and reliability of the questionnaire. The validity of designed questionnaire was evaluated by using Content Validity Ratio (CVR) and Content Validity Index(CVI) coefficients and opinion of 10 subject matter experts. Cronbach's alpha coefficient was calculated to determine the reliability of the questionnaire. The content validity index and Cronbach's alpha coefficient of questionnaire were 0.938 and 0.728 respectively, which are accepted values. Results showed that the reliability and validity of designed questionnaire were acceptable and this tool can be used to measure people awareness for a safe use of chemicals.