دو ماهنامه سلامت کار ایران
سال هشتم شماره 3 (پاییز 1390)

Background and aimsNowadays study on journals is a common work. Thus, for the first time scientific- research journal of “SALAMAT KAR- E- IRAN” has considered to be study.MethodsImportant qualitative indices in studying articles were selected at first (such as distribution of study type, number of studies and balance between subjects), then based on original documents of all volumes, they were analyzed (by Microsoft Excel 2010 software) and results were calculated via descriptive statistics methods. ResultsResults from survey and evaluation of 12 published volumes (106 articles) showed that the majority of articles were about ergonomics and safety issues. However, in some other subjects there was no article at all. Majority of them have cited the English references. Consensus was a method that has used more than the other sampling methods. Research articles conducted by Male authors were five times more than articles written by females and; Total team corporation coefficient was calculated to be 0.62. Conclusionit was concluded that there was no proper distribution between subjects of articles. English references have cited more than Persian references because of a lack in Persian references or infirmity of a comprehensive indexing system. Considering the methodological point of view the majority of studies were of observational. However, interventional and high level studies can be performed in this field, conditions and facilities must be provided in order to achieve a higher quality and quantity of studies.

Background and aimsToday in many jobs like nuclear, military and chemical industries, human errors may result in a disaster. Accident in different places of the world emphasizes this subject and we indicate for example, Chernobyl disaster in (1986), tree Mile accident in (1974) and Flixborough explosion in (1974).So human errors identification especially in important and intricate systems is necessary and unavoidable for predicting control methods. MethodsRecent research is a case study and performed in Zagross Methanol Company in Asalouye (South pars). Walking –Talking through method with process expert and control room operators, inspecting technical documents are used for collecting required information and completing Systematic Human Error Reductive and Predictive Approach (SHERPA) worksheets. Resultsanalyzing SHERPA worksheet indicated that, were accepting capable invertebrate errors % 71.25, % 26.75 undesirable errors, % 2 accepting capable(with change) errors, % 0 accepting capable errors, and after correction action forecast Level risk to this arrangement, accepting capable invertebrate errors % 0, % 4.35 undesirable errors, % 58.55 accepting capable(with change) errors, % 37.1 accepting capable errors. ConclusionFinally this result is comprehension that this method in different industries especially in chemical industries is enforceable and useful for human errors identification that may lead to accident and adventures.

Background and aimsNegative job stress puts harmful effects on physical and psychological health of workers. However, the effects of stress can be mediated by other variables. This study examines the relationship between job stress, work pressure and the rate of reported incidents. Methodsstatistical research community included all workers of Isfahan Steel Company in the winter 1388 that among them, 189 individuals were selected as sample using stratified random sampling method (from the list of workers per sector) and they responded to questionnaires including 10 questions of job stress, 4 questions of work pressure and 22 questions of the rate of reported incidents. Data were analyzed using Pearson correlation coefficients and hierarchical regression.ResultsResults showed that there was a significant internal correlation among study variables (job stress, work pressure and the rate of reported incidents) (p<0.05). In addition, regression analysis showed that job stress on the rate of incidents reported directly and indirectly through perception of job pressure was effective (p<0.05). Similarly, in the inverse mediation analysis, job stress mediated relationship between work pressure and the rate of reported incidents (p<0.05).ConclusionReducing job stress by changing workers’ perceptions of work pressure can lower the rate of reported incidents and also the reduction of work pressure perception by improving job stress can be effective in incidence of occupational accidents.

Background and aimsDuring last decades one of the hazardous agents on workers health has been workplaces noise. The aim of this study was to investigate the level of noise exposure in different jobs and noise induced permanent threshold shift in relation to noise level and work experience. MethodsThis is a cross-sectional and descriptive study that performed among total workers. Dosimetry was done for determination of accurate noise exposure level during an eight-hour s shift for each job group. Audiometry was performed in a standard acoustic room by the audiologist. The obtained data was analyzed by means of SPSS software. ResultsMean of age was 36.58 ± 6.76(19-52 years) and minimum, maximum and mean of work experience were 1, 18, 11.08 ± 5.47 respectively. Mean of hearing loss was 15.38 ±8.63 in right ear and 16.31 ±9.51 in left ear and total hearing loss was 14.72 ±8.33. A significant relationship was also identified between noise intensity and work experience with hearing loss (Pvalue?). ConclusionFindings of this study indicated that there is a high prevalence of noise pollution in different parts of workplace. Considering the obtained results, that shows positive effect of noise and work experience on hearing loss, the necessity of improvement of control and protection measures is of prime importance.

Background and aims Educating of students that have the ability to solve society problems, is considered as the most important task of universities. This important issue is achieved through effective education in a safe and stress free environment. Proper design of classroom seats proportional to anthropometric characteristics of students not only can improve academic quality but also prevent musculoskeletal disorders. In addition it may encourage students to practice correct sitting habits. This study was conducted to check the correlation of physical dimensions of students and prevalence of musculoskeletal disorder with educational chair dimensions that provided by companies. Methods This descriptive - analytical study was performed on 115 students of 18 to 27 years. 15 anthropometric parameters correlated with sitting on the chair were measured by anthropometry page and anthropometric caliper gauge. Dimensions of two Types of seats provided in the classrooms were compared with the standard seat dimensions. Results comparison of dimensions confirmed that seat dimension and students dimensions correspond with one another only in elbow length parameter and other parameters were not correspondent with each other. T-Test showed that there are significant differences between girl and boy parameters. conclusion Comparison of the results of measurement of physical dimensions and chair dimensions with results of emotional dissatisfaction questionnaire and body map chart showed that plastic chair is better than wooden type in term of comfort, chair kind and slope of back rest, and in using plastic chairs students do not have to change their sitting postures; however, due to incorrect design of foot rest and high effective depth of sea,، discomfort and pain in lower limbs is higher in plastic chairs when compared with wooden chairs.

Background and aims In order to physiologically fit the job to the worker’s capability, maximum aerobic capacity (VO2-max) is used. This study was conducted to estimate VO2-max and determine its associated factors among workers of industrial sector of Shiraz city. MethodsIn this cross-sectional study, 500 healthy male workers employed in Shiraz city industries participated voluntarily. Subjects’ aerobic capacity was assessed by ergocycle test according to Astrand protocol for 6 minutes. A questionnaire consisted of two parts covering demographic, anthropometric and physiological characteristics was used as data collecting tool. ResultsMean and standard deviation of age of workers was 32.01 and 7.66 years, respectively. Worker’s aerobic capacity was estimated to be 2.69±0.263 1.min-1. The results showed that there was association between VO2-max and age, weight and BMI while no association was found between VO2-max and height. Also, statistical analysis revealed association between VO2-max and smoking and exercise per week (P<0.05). Nature of work, shift working, job satisfaction and fatigue had no association with aerobic capacity. Based on the results, regression equations were developed for estimation of aerobic capacity. ConclusionAerobic capacity had association with age, weight, BMI, exercise and smoking.

Background and aims Dentists are occupationally exposed to elemental mercury from placements of mercury-containing amalgam. Although many studies have been conducted on mercury intoxication, there is still widespread concern about possible ill effects of chronic low-level mercury exposure on dentists. The present study examined the effects of occupational exposure to low levels of mercury by a group of dentists. MethodsIn this historical cohort study, subjects consisted of 106 dentists and 94 general practitioners (referent group), from private and public clinics in Shiraz city. Subjects were requested to complete a questionnaire on demographic variables, symptoms experienced and work practices. Additionally, using standard methods, atmospheric and urinary concentrations of mercury were measured. The data were analyzed by appropriate statistical tests. In univariat analysis, Chi-Square test was used to compare the prevalence of symptoms among both groups. Independent sample t-test and Mann-Whitney’s U-test were used to compare the mean and median of quantitative data of both groups. Multivariate logistic regression analysis was used to adjust for potential confounders. ResultsBoth groups were similar as far as most demographic and socioeconomic variables, but age and number of personal amalgam fillings, were concerned. Median of atmospheric concentration of mercury was found to be 3.35 μg/m3. Likewise, the urinary concentration of mercury in dentists was estimated to be 3.22 μg /g.creatinine. This value was significantly higher than that of the referent group. Additionally, analysis of the data revealed that subclinical symptoms of intoxication were more prevalent in dentists.ConclusionOur findings indicate that occupational exposure to mercury by dentists, even at low levels, is associated with a significant increase in the prevalence of subclinical symptoms of intoxication.

Background and aimsChlorine gas is a dangerous material that is used in chemical industries. In spite of the attempts for chlorine gas release control, sudden releases still occur in the related installations. Not taking proper emergency measures after chlorine gas dispersion may result in serious harm to health of the personnel and the people residing around the industrial area. The present study considers chlorine gas dispersion scenarios, determines emergency levels and presents an optimized pattern for more effective and faster response with the least required measures for emergency conditions control. Methods In the present paper by using Hazard and Operability Study (HAZOP) and risk matrix the possible scenarios of chlorine gas dispersion in storage tanks unit of a petrochemical complex were considered. Then the intervals of these scenarios were determined with a view to Emergency Response Planning Guideline 1-2-3. With a view to the intensity of pollution extension and the population exposed to risk the scenarios were classified in the four emergency levels defined by Center for Chemical Process Safety (CCPS). Finally for each class of scenarios with a view to the related emergency level an optimum pattern of response plan in emergency conditions was presented. ResultsOn the basis of the results of this study, chlorine gas dispersion scenario of the catastrophic explosion of the tank and scrubber system failure in the summer was classified in emergency level 4, in the winter in emergency level 3, chlorine gas dispersion due to chlorine lines rupture in the summer and winter in emergency level 3 and chlorine gas dispersion due to leakage of flanges and gaskets in emergency level 2 according to emergency levels of CCPS.ConclusionThe results of this study showed that systematic process risks analysis by use of risks recognition methods such as HAZOP and consequence analysis may have an effective role in recognition of the possible major events. Also by classification of release scenarios in CCPS emergency levels, we can select the best pattern for emergency conditions management.