نشریه طب کار
سال چهارم شماره 1 (پیاپی 7، بهار و تابستان 1391)

This study aimed to evaluate ergonomic behaviors and to determine the importance of each ergonomic behavior in an Iranian petrochemical company. This study was conducted in Khuzestan petrochemical company، which is located in the south of Iran، in 2010. The methodology was based on the Ergonomic Behavior Sampling (EBS)، and by entropy. After specifying the non-ergonomic behaviors and with reference to the results of a pilot study، a sample of 1755 was determined، with a sampling accuracy of 5% and confidence level of 95%، however، in order to have more confidence، 2631 observations were done. The results indicated that 43. 6% of workers'' behaviors were unsafe. The most frequent non- ergonomic behaviors were using of legs for load lifting (83%). The highest and lowest weights، which are obtained by entropy، belong to load carrying with correct weight behavior and neck posture behavior with weight of 0. 370 and 0. 0052، respectively. Taking into account catastrophic consequences of accidents in petrochemical industry، the results show the importance of paying attention to safety principles and to develop a positive attitude among employees toward safety

Organophosphates use in agriculture and concern about their effects on human is increasing. This study was conducted to investigate the activity of blood cholinesterase in sprayers. In a descriptive and analytical cross-sectional study، 60 (30 sprayers and 30 control individuals) with age range of 29-62 years، mean age of 44. 33±8. 55 years were studied and the results were analyzed using SPSS version 11. The average and standard deviation of erythrocyte cholinesterase (AchE) and plasma cholinesterase (PchE) concentration was 5573. 2± 1229. 51 U/L and 144. 73±52. 3 IU/grHgb، respectively. Minimum and Maximum activity of erythrocyte cholinesterase was also 71. 07 and 291. 9 IU /gr، respectively. The average concentration of both erythrocyte cholinesterase (AchE) and plasma cholinesterase (PchE) in the case group was lower than the control group. A significant difference was observed between two groups (p<0. 05). In conclusion، high exposure to organophosphates was observed and it is needed to implement the occupational health program for prevention of health effects.

Although one of the most important occupational hazards in cement industry is the effect of cement dust exposure on respiratory system، there is controversy about the relationship between exposure to cement dust and respiratory symptoms and pulmonary function impairment. Our aim was to assess the effects of cement dust exposure on respiratory symptoms and lung capacities of cement workers more thoroughly. In this retrospective cohort study، a total of 182 cement workers in two groups exposed to cement dust (case group) and non-exposed to cement dust (control group) were assessed. For exposure assessment، environmental samples of total dust were collected. For all workers after physical exam and filling ATS standard questionnaire، spirometry was done in accordance with ATS/ERS guidelines. The measured total dust levels contained a mean concentration of 17. 36 mg/m3 for exposed group and 0. 86 mg/m3 for non-exposed group. According to the results of this study، the prevalence of respiratory symptoms included wheezing، dyspnea and cough in the exposed group was significantly more than control group. A statistically significant reduction in average percent of PEF، FEV1، FEF25-75 and FEV1/FVC was seen in the workers exposed to cement dust (P value<0. 05). The highly exposed workers had a significantly higher prevalence for obstructive respiratory disease. Our survey suggests that cement production workers with exposure to cement dust are at risk of developing respiratory symptoms and reduced spirometric indices.

In the rapid progress of global industrialization، occupational accidents have created major problems for countries including our country. Recently، researchers have reported that more than 75 to 90 percent of the work accidents have been related to unsafe behaviors of workers. Therefore، recognition of unsafe behavior types، and factors influencing them، would help prevent such behaviors. In this descriptive cross-sectional study unsafe behaviors of workers in Kermanshah oil refining company were evaluated and analyzed using safety behavior sampling technique. Data were collected using direct observation of workers’ behaviors، checklist، interview techniques and review of previous health and medical records. After a pilot study and considering the definition of different unsafe behaviors، required sample size was determined as 4014 observations. Demographic variables related to unsafe acts were collected by using relevant questionnaire. Observations during the study showed that 24. 5 percent of workers'' behaviors were categorized as unsafe. Also data showed that there was a significant relationship between workers’ unsafe behaviors and work unit، job، marital status، age، educational levels، work experience، and history of previous accidents (p<0. 001). But there was not a significant relationship between observation days and unsafe behaviors (p>0. 05). In order to reduce unsafe behaviors and incidence rate of accidents، planning and implementation of training courses based on principles of safety behaviors، creating an appropriate safety climate and safety culture، workers involvement in safety performance، precise supervision on implementation of safety regulations and use of scientific experiences of academic researchers are suggested.

Work-related musculoskeletal disorders are the most common occupational diseases. Between industries، pottery، with several thousand years of activity، still retains its nature as a manual job. This has led to increased risk of musculoskeletal disorders among potters. The aim of this study was to assess the prevalence of musculoskeletal disorders and related risk factors by OCRA method in Meybod potters in 2009.

This was a cross-sectional analytical study. Target population consisted of، all potters working in the pottery workshops in Meybod. There were 17 workshops with 54 potters. Information about the prevalence of musculoskeletal disorders was collected using Nordic questionnaire. The OCRA method was used to assess risk factors for musculoskeletal disorders of upper limbs.

The results of Nordic questionnaire showed that approximately 59. 3% of the potters had at least one upper extremity musculoskeletal disorders in the last year. Wheel workers had the highest prevalence (34. 4%). Independent T-test showed no significant difference between the final score of OCRA index between potters with and without upper extremity musculoskeletal disorders (P=0. 047).

The results of this study showed that the risk of musculoskeletal disorders of upper extremities is high among potters. So it suggested that possible corrective actions take place as soon as possible and periodic evaluations are also necessary for early detection of these disorders.

Garbage collectors form a large group of municipal workers who have occupational exposure to different airborne contaminants. The aim of this study was to evaluate the respiratory health of a group of garbage collectors who were working in Fars province. This cross-sectional study was undertaken among a group of 105 garbage collectors and 93 referrent individuals. Subjects were interviewed and respiratory symptom questionnaire، as suggested by the American Thoracic Society، was filled for them. Additionally، the parameters of pulmonary function were measured after two days of rest (before commencement of the saturday morning shift) for both garbage collectors and the referent subjects. sAnalysis of the data showed that some symptoms of respiratory disease such as shortness of breath (39%)، productive cough (9. 52%)، wheezing (18. 09%) and phlegm (10. 47%) were significantly (p<0. 05) more prevalent among garbage collectors. Similarly، significant decrements in FEV1 and FEV1/FVC ratio were noted in garbage collectors when compared with referent individuals. The spirometric pattern of ventilatory disorder was consistent with that of obstructive pulmonary diseases. Our data indicate that the prevalence of respiratory symptoms as well as lung function impairments are significantly higher in garbage collectors than in their counterparts (referent group) and this is likely to be attributed to their exposure to bioaerosols، exhaust fumes and other workplace contaminants

Serotonin plays an important role in central fatigue and increases the release of prolactin. To determine the effect of one exhausted endurance exercise session on serotonin serum level of men runners، this study was conducted. In a laboratory cross-sectional study، blood samples of 14 runners were collected and the level of serum serotonin and prolactin was measured before، immediately after and 10 minutes after exercise using Bruce protocol. Data were analyzed by SPSS 18. According to the results، the average level of serum serotonin before، immediately after and 10 minutes after exercise was 141. 26، 241. 04 ng/ml and 214. 34 and for prolactin was 7. 53، 11. 83 and 16. 84ng/ml، respectively. There was significant difference between both serotonin and prolactin levels and the time of exercise (p<0. 05). The present study indicates that one exhausted endurance exercise session can increase blood serum serotonin and prolactin level and fatigue then after. It can be recommended that moderate exercise is useful for ordinary individuals.

Work ability is an interaction between individual and occupational factors influencing the working life of employee and is an important factor in working quality and security. The aim of this study was to determine the work ability in midwives.

This was a descriptive study on123 midwives employed in the public hospitals and health-care centers of Mashhad meeting the inclusion criteria. The subjects were selected by two- stage sampling method. Participants completed questionnaires about demographic information، work characteristics and Work Ability Index (WAIQ). Collected data were analyzed using SPSS version 14 and statistical tests such as independent t-test، one way ANOVA and Pearson،s correlation test were used.

Results showed that mean ± SD of age and work ability of midwives was 32. 7± 1. 02 and 38. 81±0. 05 years، respectively. 0. 8% of midwives had poor، 31. 73% moderate، 49. 59% good، and 17. 88% excellent work ability. Also، there was a significant negative correlation between work ability and work experience (p=0. 011، r = -0. 431).

Midwives work ability was generally low in Mashhad. It can be increased through such special ways as dividing tasks among the members for lowering workload and periodic examination by physicians.

Safety culture is a factor that because of it all of workers from headmaster to simple workers come together so that they could contribute to the safety of themselves and their coworkers. The purpose of this study was to evaluate factors affecting safety culture in Yazd steel industry workers. This study was conducted on 244 steel industry workers. In this cross-sectional study، data was gathered by a questionnaire. This questionnaire consisted of 75 questions in the form of multiple choice questions (standard safety culture questionnaire) and 6 questions about accidents (accident questionnaire). Data was gathered and after being coded was entered into SPSS software for analysis. In this study there was a significant relationship between safety culture and educational level and work experience (p-value<0. 05). There wasn’t a significant relationship between safety culture and age، marital status، work shift and location of body involved. In this study the most frequent cause of occupational accidents was burning (25%) and upper extremities were the organs most frequently injured. In order to achieve system requirements about safety، it is necessary to implement a proper structure and in order to match individuals with this structure، culture change and behavior change should be used.

Flour dust is one of the allergens in the workplaces and its occupational exposure can cause respiratory impairments. The purpose of this study was to investigate the respiratory effects of exposure to flour dust in flour mill workers. This cross-sectional study was carried out at 6 flour producing factories in Razavi and South Khorasan provinces، Iran. Study subjects included 180 males (90 male workers with current exposure to flour dust and 90 male non-exposed employees). Determination of dust concentration was carried out with personal dust sampler at all production units of studied industries. Respiratory symptoms were investigated with American Thoracic Society questionnaire (Persian version). Lung function tests were done by a calibrated spirometer. The data were analyzed using SPSS (version 16). Mean of age and work experience of exposed group was 36. 8±9. 03 and 12. 0±5. 6 years، respectively. This result، for non-exposed group was 37. 3±8. 1 and 12. 58±5. 5 years، respectively. Atmospheric concentrations of respirable and inhalable dust were 13. 3±2. 38 and 38. 77±3. 6 mg/m3، respectively. Results indicated that prevalence of respiratory symptoms in exposed subjects was significantly higher than non-exposed workers. Likewise، pulmonary function parameters were significantly lower in exposed than reference group (p<0. 05). The findings of this study showed that occupational exposure to flour dust and age could be important factors predicting the prevalence of respiratory symptoms and functional impairment of the lungs