Journal of School of Public Health and

---

Background and Aim: One of the most prevalent occupational diseases and conditions is musculo-skeletal disorders (MSDs) that impose expensive medical-recompense expenses, organic damages, and work-time wasting. The aim of this study was to detect spine curvatures (cervical, back/ low back, lumbar) and prevalence of musculo-skeletal disorders in assembly workers of Bahman automobile company, Tehran, Iran.

Materials and Methods: In this cross-sectional, descriptive-analytical study 160 assembly workers of Bahman Automobile Manufacturing Company (vans, cars), Tehran, Iran were included. In the descriptive part data were collected on the demographic characteristics of the subjects. In the analytical section associations among the dependent variables, as well as between the dependent and independent variables, were determined. The Nordick Questionnaire, a scale, and a flexible ruler were used for data collection. The SPSS software was used for data analysis.

Results: Although the mean age of the participants was low (30.89 yrs), the prevalence of MSDs was high (69.4% 1.58). The most prevalenct of the MSDs was in the lumbar part (n=83 %51.9) and the least in the hip and femoral region (n=9: %5.6). Significant associations (p < 0.05) were found between MSDs prevalence and independent factors (age, years of working, marital status). However, cervical, back, lumbar curvatures and the Delmax index were not statistically related with MSDs.

Conclusion: This study shows that associations exist between muscleo-skeletal disorders and age, years of working, height, and marital status. The findings also reveal that there is no relation between MSDs and the vertebral curvatures (cervical, back, lumbar), except the neck curvature in the car (not van) assembly workers. It may be concluded that genetics and environmental conditions can adversely affect the musculo-skeletal health. We cannot control the genetic factors. However, one can provide more favorable environmental conditions. For example, employing younger workers may help decrease the musculo-skeletal disorders.

---

Background and Aim: Application of modern technologies and changes in industries and work practices, particularly in assembly lines, have resulted in increased work-related musculoskeletal disorders (MSDs). This has led to reduced occupational competence in both industrialized and developed countries. This study was conducted to determine the prevalence of MSDs in the upper limbs, postural loading on the upper limbs (using the LUBA technoque), and ergonomic risk factors among assembly workers of an Iranian Telecommunications Manufacturing Company (ITMC) in Shiraz, Iran.

Materials and Methods: In this cross-sectional survey data were collected, using the Nordic Musculoskeletal Disorders Questionnaire (NMQ) and LUBA Checklist, on 193 randomly selected registered assembly workers from 8 units of the assembly line of ITMC, Shiraz, Iran. The statistical tests used were as follws: 1.The qui-square test, to determine factors causing MSDs 2. One-way analysis of variance and Kruskal-Wallis to determine postural loading index 3. Logistic multiple regression analysis, to determine risk factors.

Results: Lower-back symptoms were found to be the most prevalent problem (67.9%.) among the workers. The findings also showed that the upper limb disorders were significantly associated with age, sex, job, daily working time, work evironment conditions, and twisting (P<0.01). Based on LUBA, a large majority of the workers (89.64%) had experienced high postural loading (PLI = 5). In addition, significant associations were found between postural loading and symptoms of upper limbs and units of work (P <0.05).

Conclusion: Based on these findings, MSDs are prevelent among Telecommunication Manufacturing Company in Shiraz, Iran. The most important factors likely to cause MSDs are postural loading on the limbs and unfavourable working conditions. Interventional programs aimig at preventing musculoskeletal problems among assembly line workers should focus on reducing postural loading.

---

Background and Aim: The large volume of reports and statistics in the literature on the prevalence of musculoskeletal disorders (MSDs) in Iran and other countries indicates that it is essential to assess the ergonomic situation in different occupations. These disorders can be caused by long-term exposure to different agents or by trauma to the musculoskeletal system. A large part of the work force in Iran is engaged in general construction and dam construction workshops. The postures of these workers while working in the workshops are unsuitable postures. The objective of this study was to assess the ergonomic situation of workers in dam construction workshops.

Methods and Materials: This was a cross-sectional study conducted in 2008. The sample included 110 randomly selected male-workers in a dam construction workshop in Takab City, Iran, engaged in 25 different jobs. Data were collected using the Nordic Musculoskeletal Questionnaire and the National Institute of Occupational Health-Center to Protect Worker Rights Checklist (NIOSH-CPWR), both developed by the National Institute of Occupational Health-Center to Protect Workers Rights. The software used to analyze data was SPSS.

Results:The average service record of the workers was 36.6 ± 86.8 months. The data show that the most common (55.5%) MSDs were in the low back region. There were statistically significant positive associations between prevalence of MSDs and many independent variables, namely, age, weight, education level, service record, smoking, type of job, lengths of time of standing and sitting at work, total duration of work, work pressure, undesirable postures, and surface for walking.

Conclusion: The results of this study generally confirm findings of previous investigators. It can be concluded that ergonomic assessment of jobs may give valuable information to be used by occupational health and safety authorities in planning preventive and educational programs.

---

  Background and Aim: Human error often plays an important role in accident causation either through direct action or poor design . The focus of this work is was on prediction of human error probabilities during the process of emergency musters on in gas compressor stations . This paper aims to present a brief description of Human Error Probability Index (HEPI) for the on gas compressor station musters process.

  Materials and Methods : Due to a lack of human error databases, and in particular human error data on gas compressor station musters, an expert judgment technique, the Success Likelihood Index Methodology (SLIM), , was adopted as a means to predict human error probabilities Two muster scenarios of varying severity (gas release, fire and explosion) were studied in detail . A total of 34 reference graphs provided data for both the weighting and rating of six performance shaping factors and the data were subsequently processed by means of SLIM to calculate the probability of success for 16 muster actions ranging from point of muster initiator to the final actions in the temporary safe refuge (TSR). The actions were categorized into 4 phases, namely, awareness, evaluation, egress, and recovery phases. The six performance shaping factors considered in this work were stress, complexity , training, experience, event factors, and atmospheric factors .

  Results: Human error probabilities in the egress phase were highest, followed by those in the evaluation phase the lowest were in the awareness phase.

  Conclusion: The HEPI can be applied to limit the chances of human error occurrence and mitigate the consequences of such errors through changes in training, design, safety systems, and procedures, resulting in a more error-tolerant design and operation .

---

Background and Aim: Today in many work environments, such as nuclear, military and chemical industries, human errors may result in disasters. Accidents in different parts of the world bear evidence to this examples are the Chernobyl disaster (1986), the Three Mile Island accident (1974), and the Flixborough explosion (1974). Thus, identification of human error, especially in complex and intricate systems, and devising control measures are essential.

Materials and Methods: This project was a case study conducted in Zagross Methanol Company in Asalouye (South Pars), Iran. The walking-talking-through method was used to collect the required data and complete the Systematic Human Error Reductive and Predictive Approach (SHERPA) worksheets. The process experts and control room operators were interviewed and technical documents of the Company examined.

Results: Analysis of the SHERPA worksheets indicated that the majority (48.62%) of the 222 errors identified were action errors, followed by checking errors (31.97%), retrieval errors (6.75%), selection errors (0.9%), and communication errors (11.7%).

Conclusion: The results of this study show that the method can be used effectively in different industries, especially chemical industries, to identify human errors that may potentially lead to dangerous situations and accidents.