مجله مهندسی بهداشت حرفه ای
سال ششم شماره 3 (پاییز 1398)

The most common way of transporting hazardous materials in many countries, including Iran, is road transport. This increases the risk of exposure to these materials. Hence, the assessment of the consequences of exposure can help to manage the transportation of these materials. Therefore, the purpose of this study was to assess the health consequences of accidents in road transport of chemicals.

In this study, a fuzzy inference system was designed and implemented. The system has three input parameters: "The concentration of released chemicals", "The degree of vulnerability of the exposed community" and "The toxicity of the released material". The output of this system expresses the degree of exposure severity coefficient. This coefficient demonstrates the severity of the damage to individuals in the exposure of chemicals.

Due to the release of chlorine gas in the target area, the radii affected were divided into two low risk areas (up to 187 m) and safe (more than 187 m). The most severe exposures in the sensitive group of society (children, elderly people and individuals with underlying problems in group 4 with a coefficient of 0.92) and adolescents and middle aged in group 3 (with severity coefficient of 0.776).​

Our results showed that group 4 was considered as the most sensitive exposure group in determining the safe distance. Also showed that the use of fuzzy approach to simulating the health consequences of chemical transport can be used.

Analyze the causes of accidents to control and prevention of accidents is necessary.This study was conducted to analyze the causes of disability accident in a dam construction project using Tripod Beta-SCAT combination method.

A critical event was selected and the causes were identified, employing Tripod Beta-SCAT method. In this sense,first, interface causes and root causes obtained by the Tripod Beta method. Then, the obtained causes and the control measures were placed in SCAT table. The effect of causes of accidents and their ranking were determined using Chi-Square Test and Friedman test, respectively. Accordingly, appropriate control measures and necessary suggestions were provided.

underlying cause were identified in 6 classes. Maintenance management ( 25%) and training (20%) had the highest rank and executive instructions (5%) had the lowest. 13 preconditions were also identified. Most important indirect cause was "the inappropriate machine lifting factor (2.69)". Most important root cause was "the erosion and excessive deterioration of the mechanical excavator (4.55)". Furthermore, the most important control measure was “the inspection and control of the operation (5.05)". There was also a significant relationship between indirect and root causes (significance level 0.001 and correlation coefficient 0.608).

Combined method presented in this study has in many cases met the needs of different organizations and is currently one of the most important methods for analyzing the accidents causes. The combination of SCAT with other methods will be useful for analyzing the causes of other accidents on dams and construction projects.

The physical conditions of the workplace has an impact on the health of employees and the quality of their work. Measuring the working environment of the office can be a good basis for improving the ergonomic conditions of the employees' work environment. This study aims to design a valid and psychometrically evaluated questionnaire for measuring administrative work environment.

After studying and researching the theoretical foundations of ergonomics and examining the office environment, an initial 22-item questionnaire for assessing office work environment was designed. The formal validity of the questionnaire was evaluated qualitatively by 4 experts. For content validity (examine the question in terms of necessity, relevance, clarity and simplicity) by quantitative method (CVI & CVR), the questionnaire was presented to 20 experts. 30 employees of the Iranian Gas Engineering and Development Company were verified the reliability of the questionnaire and the Cronbach's alpha coefficient was calculated using SPSS software.

Based on the content validity results, 21 question of questionnaires were approved and 1 question was rejected.  The average content validity ratio and average content validity index were respectively 0.73 and 0.94. The Cronbach's alpha coefficient was evaluated for the questionnaire total of 0.935, for the Office accessories component of 0.916, the environmental condition component of 0.922 and the environment layout component of 0.821.

The 21-item questionnaire for administrative work environment assessment has an appropriate validity and reliability for evaluating the administrative environment Conditions of ergonomics and can be an effective tool for related research.

Pipeline inspection gauges (PIG) operation which is called “pigging operation” is a practical online monitoring method for maintaining pipeline in a healthy and safe condition. This operation requires high man-machine interactions. Therefore, it is sensitive to human error which can lead to catastrophic consequences.

This descriptive study was carried out to estimate the probability of human error in pigging operation in a gas transmission plant in Iran. First, hierarchical task analysis (HTA) was conducted through walking through the pigging operation and doing interviews with workers. Next, the Standardized Plant Analysis Risk-Human (SPAR-H) methodology was utilized for estimation of human error probability.

SPAR-H methodology was implemented on PIG operation.  The mean human error probability (HEP) value was calculated to be 0.218. HEP value in “opening bypass valve for decreasing pressure” subtask was recognized as the highest probability of human error (0.841).

SPAR-H method is a useful tool for practitioners to calculate HEP. Besides that, based on results some of the preventive actions to reduce HEP are as follow: using more clarified procedures, the automation of the launching and the receiving processes and etc

Investigations show that human error is one of the main reasons for driving accidents. Drivers' performance is shaped by various factors such as age, gender, driving environment; which one of the most important factors is the workload. The current study aimed to investigate the relationship between mental workload, situational awareness, and drivers' work experience.

Twenty-six taxi drivers with different work experience, dividing into two groups, participated in this study. Driving activity load index (DALI) was used for assessment of drivers’ workload and participants’ situation awareness was measured by situation awareness global technique (SAGAT).

The results show that driving in a long time will increase the mental workload in all dimensions of the driving activity load index (p <0.05), among which, the highest correlation is related to visual demand (r = -0.397, p = 0.045). There was a significant relationship between increasing workload and drivers’ work experience (p = 0.01). The results also showed that, as drivers’ mental workload increases, their global situation awareness decreases (p <0.001).

The results of this study indicate that increasing driver’s work experience, results in decreased mental workload, and global attention and situational stress are factors with the most different amounts among people with different work experience. Also, increasing workload, lead to decreasing perception level in situation awareness; drivers with more work experience have less decreased amount in perception level. Decreasing perception level in drivers leads to decreasing global situational awareness.
Key words: Driver's mental workload, Situation awareness, Work experience

The most common problems of firefighters is the loss of performance while using protective gloves. Due to the variety of fire gloves in Iran, this study aimed to investigate and compare the effect of these gloves on hand dexterity performed.

Two models of the most common firefighting gloves were selected for investigation. Dexterity was evaluated using four standard tests such as Bennett, Minnesota, Pegboard and Modified Pegboard in forty male students for both gloves. The Spearman correlation coefficient, Wilcoxon, and Friedman test were used to comparison dexterity and effective factors.

The type of gloves has a significant effect on dexterity (P< 0.001). The findings showed that the modified Pegboard test has high sensitivity and can be used to measure fingers dexterity. Pegboard test is not suitable for measuring dexterity due to lack of sensitivity and severe reduction in scores. Bennett and Minnesota tests can be used to measure the overall hand dexterity due to their same trends. But Minnesota according to less fatigue and solving other problems, can be used instead of the Bennett test.

The various gloves of the firefighters in the market have different effects on the dexterity of the hands and fingers that firefighting organizations should pay attention to it. Modified Pegboard and Minnesota tests are recommended to assess dexterity when using firefighting gloves.

job stress is one of the factors affecting workers occupational productivity and health. In recent years, stress has been emphasized as an alarm that results in loss of productivity and efficiency. The purpose of this study was to investigate the effect of job stress on worker productivity in one of the Southwest Oil and Gas Companies.

In this study, two separate questionnaires were used to collect job stress and productivity information. The validity and reliability of these questionnaires have been reviewed in previous studies. All data was processed by SPSS 24 software. 

The mean score of job stress was 3.68 ± 0.43. The results showed that 36.4% and 63.6% of workers had low and no stress, respectively. It also found that productivity with job stress and each of the indicators related to  role, relationship, support of authorities, support of coworkers, demand had a significant and inverse correlation (p <0.05). Productivity was also significantly correlated with age, work experience and education (p <0.05).

Controlling occupational stress and related factors in the workplace is one of the strategies to increase productivity, because there is a significant and inverse relationship between the mean of job stress and productivity.

Heat Stress in Oil and Gas Industries Is Important Concern in Safety and Health fields. The Aim Of Study Was Comparison To The Heat Stress By Experimental And Analytical Index In Two Oil Terminals In The North And South Of Iran.

This Descriptive-Analytical Study Was Carried On 130 Employees Of Neka And Kharg Oil Terminals. In This Research, HSI, AET, WBGT And P4SR Indices Were Calculated. In Order To Validate These Indicators, The Oral Temperature And Tympanic Temperatures Of Employees Were Studied. Data Analysis Was Performed Using 22spss Software.

Significant Correlation Was Found between Physiological Indices and Thermal Indices in Indoor Environment Kharg and Neka .There Is Not Significant Relationship With HSI Index. In The Outdoor Environment Kharg .Significant Correlation Was Found For All of The Indices Except For HSI Index. In Neka, With The Exception Of The HSI Index, Was Significant Correlation Between Oral Temperature And Thermal Indices, But There Is Not Significant Difference Between The Tympanic Temperatures With Thermal Indices (P> 0.05). WBGT And AET Indices Had A Significant Difference In Both Terminal Environments. The HSI Index Were not Shown Any Significant Difference at Any of These Terminals. The P4SR Index Was Not Significant Different In the Indoor Environments of Two Terminals (P> 0.05).

It was found that WBGT index and AET index are reliable indices for assessing thermal stress in oil terminals. According to them, the amount of thermal stress in outdoor environment in Kharg oil terminal was higher than NEA oil terminal.