دو ماهنامه سلامت کار ایران
سال دهم شماره 3 (امرداد و شهریور 1392)

Developing intelligent systems to prevent car accidents can be very effective in minimizing accident death toll. One of the factors which play an important role in accidents is the human errors. Fatigue driving is one of the cases that can cause errors and reduce accuracy in contorlling the vehicle. The signs of fatigue and sleepiness while driving is revealed based on video processing techniques. In this model، the person’s face is filmed by a camera in the first step by receiving 15fps video sequence. Then، the images are transformed from RGB space into YCbCr and HSV spaces. The face area is separated from other parts. That the eyes are open or closed in a specific time interval is determined by focusing on thresholding and equations concerning the symmetry of human faces a finally using K-means Clustering، the frequency of yawning is identified. In the evaluation phase، the implementation of the algorithm on video sequences recorded under real conditions in urban and suburban areas and compared with methods such as Visual Information and Monitoring Driver Vigilance، better performance was achieved. The proposed system has been implemented on different video sequences with average accuracy of 93. 18% and detection rate (DR) of 92. 71% out of total 5900 image frames. High accuracy in segmentation، low error rate and quick processing of input data distinguishes this system from similar ones. This system can minimize the number of accidents caused by drivers’ fatigue

Employee examinations are one of the components of occupational health surveillance and the second level of disease prevention. The aim of this study is to determine the prevalence of general and likely occupational diseases among workers referred to an occupational medicine center in Mashhad and the role of theses examinations in early diagnosis of diseases. This descriptive study was done on the 3248 participants were referred to Shahid Ghodsi occupational medicine center. In this study، subjects were examined by a general physician and based on their exposure para- clinical tests were requested. Then the people who had an abnormality in these tests، were asked about their awareness or unawareness. Finally، all the information was recorded in the standard examinations form and data were analyzed using SPSS software version 18. In this study 81. 9% of participants were male and18. 1%were female. The mean of age and BMI was 31. 18 and 22. 7 respectively. The20. 9% of the subjects had a history of smoking. In this study، the most common diseases were dyslipidemia (34. 3% cholesterol and 14. 6% triglyceride elevation)، visual acuity reduction (22. 9%) and hearing loss (21%). The 84. 6% of participants with sensor neural hearing loss، 64. 6% of participants with visual acuity reduction and 87. 7% of participants with hyperlilipidemia were unaware of their disease. The findings of this study show that most of participants were unaware of their disease، so pre employment examinations is effective in early detection of diseases of workers

Audience analysis has important role in designing behavior change interventions. In this study، we aimed to measure attitudes and behaviors related to usage of personal protective equipment (PPE) to design an intervention for persuading employees to use PPE in their work settings. In this cross-sectional analytical study، an attitude and self- reported behaviors questionnaire and an observational checklist were used to measure the attitudes and behaviors related to usage of PPE in all 44 employees. Then، the collected data were analyzed. Labors have relatively desired attitudes toward using PPE. Most labors reported that they always or usually had used PPE while working. During observation، we explore that PPE usage was not good at all and some PPE like safety helmets، masks and safety clothes were used less by them. Regardless of having desired attitude and self-reported behaviors، people might have risky behaviors. So، we must notice to virtual behaviors and their causes to have a successful program. Identifying and analyzing audience is necessary to design an effective behavior change intervention.

Musculoskeletal disorders (MSDs) are the most important causes of workers disabilities، increasing compensations and reducing productivity in developed and developing countries. According bureau of labor statistics in 2010، 29 percent of injuries and musculoskeletal disorders are diseases that cause absence from work. The objective of this study is determining the role of response efficacy as one of the component of protection motivation theory to reduce ergonomic risk factors in one of manufacturing industries. In this cross-sectional analytical study 158 workers of an assembly industry were studied. In order to assess the ergonomic work stations. Quick Exposure Check method was used. The data gathered via exclusive interviews with selected workers using the questionnaire designed based on protection motivation theory and were analyzed. Content Validity Index and Content Validity Ratio values were calculated for validity and reliability was obtained by using Cronbach''s alpha coefficient. Results of the assessment to the QEC method showed that 37. 97% and36. 71% respectively of those at moderate and high risk groups. Also there was a significant negative correlation between response efficacy and QEC scores and action level Regarding negative significant correlation between self efficacy and QEC scores and action levels، designing educational program based on Protection Motivation Theory to decrease ergonomic risk factors is recommended.

Sleep is one of the most important day and night cycles and a complex biological pattern. It is necessary for humans physical and mental balance as sleep disturbance is often an early sign of mental illness. The purpose of this study is to survey and comparison of sleep disorders in shift workers of an automotive industry. This descriptive- analytical study has been conducted on 120 workers in an automobile manufacturing industry located in Tehran. Samples are selected using simple sampling. Data collection was included three questionnaires، demographic data، Insomnia Severity Index and Epworth Sleepiness Scale. The research data were analyzed using SPSS software. Insomnia Severity Index scores 16. 3 on the night shift with a standard deviation of 6 and 12. 55 in the morning with a standard deviation of 5. T-test results showed that the severity of insomnia is higher in unmarried than married individuals (P =. 004). Comparison scores on the night and morning shifts، using t- test، show that the average sleepiness scores in night shift is higher than morning shift، and is statistically significant (P =. 048). The results of this study indicated the high incidence of insomnia and sleepiness in workers in this vital industry. These results can be disturbing and may affect the quality of work and accident rates

«circadian» is the changes of behavioral and metabolic activity during day and night in living organisms. The human body has circadian rhythm too، which is repeated every 24 hours. The aim of this study is to determine the validity and reliability of the 11Q of CTI questionnaire، according to Iranian workers society. Translation and cultural adaptation of CTI questionnaire was performed according to standard methods of Translate & Back translate. The content validity was done using the opinions of 10 experts. In this study، 30 rotating shift worker (SW) nurses and 30 employees of Day worker (DW) from Kerman University of Medical Sciences completed their questionnaire. To check the reliability the Cronbach''s alpha was used followed by factor analysis to confirm the validity of the questionnaire. Data analysis was performed using the Lisrel 8. 8 and spss18 software. The questionnaire contains two domains: Rhythm stability of circadian and rhythm amplitude of circadian. Overall reliability of the questionnaire using Cronbach''s alpha was calculated 0. 76. Cronbach''s alpha for amplitude and stability of rhythm for rotating nurse shift worker (SW) respectively was 0. 70 and 0. 82. Values of Cronbach’s alpha index for two domains were equal to 0. 75 and 0. 78 in day workers (DW) employees. The Kaiser index was 0. 79، which indicates good conditions for the factor analysis. Chai-Square of Bartlett''s test obtained (p-value< 0. 0001) Shows the correlation between variables. Principal component analysis was performed with Varimax rotation analysis. With considering a two-factor model، 54. 3% of the total variance was explained by two factors، the 39. 51percentage was assigned with the first factor and 14. 82% for the second factor. The Persian version of the CTI questionnaire can be used as a valid and reliable tool for determining the type circadian

Work-Family Conflict (WFC) occurs when People may have to do several roles such as employment، spousal and parenting at the same time. This conflict leads to negative outputs such as work absence and increased turnover. The purpose of this research is to study and compare the work-family conflict in clinical and non-clinical (supportive and administrative departments) staffs of a hospital. This research is a descriptive-analytical study that has been done by quantitative and cross-sectional method. The community of the study was married workers of Shahid Faghihi hospital in Shiraz City. The main data collection tool was a questionnaire I. In order to measure work- family conflict Field (2002) questionnaire was used. The validity has been approved by relevant experts and its reliability has been confirmed with Cronbach’s alpha. For statistical analysis one-way ANOVA and t-test were used. Work-Family Conflict has been significantly different between Clinical and Non-Clinical staffs of hospital (P ≤0. 001) and it was perceived that in Clinical staff was more than Non-Clinical staffs (administrative and support). In addition، perception of all four dimensions of conflict، by various staffs has had a significant difference (P ≤0. 001). The Work-Family Conflict was perceived among women and men differently and women perceived more conflict (P ≤0. 001) Based on the findings of this study it can be concluded that clinical and female staffs are faced with work-family conflict more than the others in hospital. Therefore it is recommended that the responsible authorities should stay focused on these groups providing appropriate legislations and supporting programs to reduce work family conflict among staffs particularly in such groups.

n-hexane is widely used in the production of glues، lacquers، paints، plastic، and rubber products. Therefore، a significant potential for exposure to this toxic solvent exists in industrial settings. This study was carried out to assess the exposure to n-hexane and to determine the correlation between this exposure and urinary concentration of free 2،5-hexanedione (2،5-HD). Thirty-eight male workers from 7 shoe making workshops were studied. Individual exposure of workers to n-hexane and urinary concentration of 2،5-HD among them were determined. Data were analyzed using the SPSS/PC statistical package version 16. 0. The calculated time-weighted average (TWA) of exposure to n-hexane and the average urinary concentration of free 2،5-HD were estimated to be 78. 6 mg/m3 and 0. 23 mg/l، respectively. A significant correlation (r = 0. 815) was found between time-weighted average of exposures to n-hexane and urinary levels of free 2،5-HD. Significantly higher urinary concentrations of 2،5-HD detected in subjects who did not wear gloves. Workers’ average exposure to n-hexane and the levels of 2،5-HD in their urine did not exceed the current recommended TLV-TWA and BEI for this chemical. Additionally، they provide further evidence in favor of the notion that free 2،5-HD is an appropriate indicator for biological monitoring of workers exposed to n-hexane. Finally، it is implied that dermal exposure also plays an important role in the overall absorption of n-hexane by the human body

industrial development and application of new methods to improve production resulted human errors to be considered more seriously. With this intention، the use of human error identification techniques followed by application of remedy to analysis human errors and decrease of their occurrence probability and criticality became main discussion of scientific and industrial meetings. In addition it can be noticed that by different techniques، human error identification، evaluation and control are performed by better precision and this three-step process is the purpose of this study.

In this descriptive epidemiological study by using both methods of SHERPA and HET human errors has been detected in the Ancoiler device control room of number 3 factory of Ahwaz Pipe Mill. This study is conducted with the application of two techniques in order to obtain two viewpoints for human error identification. With this intention work sheets of two techniques were completed followed by interview with Ancoiler operator and construction director and factory director.

The most occurred and likely to occur errors in this unit are related to operating errors occurred at different levels of forgetfulness، poor effort، and mistiming the task.

In the control unit the high percentage of errors is allocated to action error. Further the application of two complementary techniques simultaneously can assist to identify errors greatly.

Musculoskeletal disorders (MSDs) are one of the most common causes of occupational injuries that appear in back، neck and upper limb mainly. This study was conducted with the objectives of determination of prevalence rate of MSDs and ergonomics assessment of the risk of MSDs in workers of a petrochemical company. In this study، 327 randomly selected workers in a petrochemical compan y with at least one year work experience in office and operational units participated. O ffice and operational staff were studied separately d ue to different nature of their works. In office jobs، data were gathered using demographic questionnaire، Nordic musculoskeletal disorders questionnaire (NMQ) and ergonomics checklist for assessment of working conditions. In operation jobs، demographic questionnaire، NMQ and QEC method were applied to collect the required data. Data were analyzed using statistical tests including t-test، Chi-square and test of proportion by SPSS software (Version 16. 0). Means of age and job tenure of study subjects were found to be 32. 2±6. 63 and 5. 53±4. 01 years، respectively. Prevalence rates of MSDs in office and operation staff were 68. 1 % and 46. 6%، respectively. The r esults showed that the prevalence of musculoskeletal disorders in neck، back، low back and knees in the office staff were significantly higher than those of operational workers. Working condition assessment by the checklist in office staff revealed that the lowest index wa s related to posture and workstation. This means that in the corrective program improving working posture should be considered as a priority. The results of assessment of physical exposure to musculoskeletal risks by QEC technique among operational workers showed that in 38. 4% of workers studied، the level of exposure to musculoskeletal risks was in Action L evel (AC) 1، 19. 2 % in AC 2، 31. 5 % in AC 3 and 11% in AC 4. Totally، in 42. 5% of workers studied، the level of exposure to musculoskeletal risks was high or very high. This indicated that the jobs and working conditions in the operational units were conducive for developing MSDs and needed corrections. Based on the results، some interventional measures were implemented. The prevalence of musculoskeletal in the office staff wa s significantly higher than that of operational subjects. In working conditions improvement، taking risk factors of lower back، neck، upper back، knee، shoulder and wrist into consideration seemed essential.