Redesign and ergonomic assessment of a chest-support baby walker.

BACKGROUND: Parents often use baby walkers (BWs) as assistive devices to improve their infants' independent movement and motor skill acquisition. However, the literature suggests that conventional baby walkers (CBW) may cause delays in an infant's ability to walk independently and musculoskeletal burden on parents. OBJECTIVE: In the current study, a baby walker (RBW) with chest support was redesigned and ergonomically assessed during an infant-walking task. METHODS: The anthropometric dimensions of 90 infants aged 7-11 months were measured in the city of Urmia, northwestern Iran. Following redesigning based on the results from expert panel meetings and prototyping of the RBW, 18 mothers (age: 28.33±4.27 and height: 163.75±5.32 and weight: 59.45±5.99) with their infants (9 boys and 9 girls) performed a simulated infant walking task in two experimental sessions using the CBW and RBW over a repeated measurements design. The infants' feet track patterns, including the number of steps and step distances were assessed via the image analysis of the footprints. The mothers' body posture and lower back spinal load were evaluated using Rapid Upper Limb Assessment (RULA) technique and 3D Static Strength Prediction Program (3DSSPP), respectively. RESULTS: Wilcoxon signed-rank tests showed infants walked more steps with the RBW (p = 0.002). Similarly, the distance between the infants' left heel strike (p = 0.008) and their right and left toe-off (p = 0.03 and 0.02 respectively) was also significantly lower in the RBW use. Additionally, the body posture of mothers was improved (RULA final score from 7 for CBW to 5 for RBW). Moreover, lower back compression and shear forces were reduced significantly (p = 0.002) by the RBW use. CONCLUSION: According to the feet track pattern, infants took more balanced steps when the RBW was used. In addition, mothers were subjected to less pressure on the lumbar region when they placed and lifted their infant from the RBW. However, further work is necessary to investigate potential long-term effects of the RBWs use.

Design and ergonomic evaluation of a new adapted endoscope holder to reduce muscle pressure and discomfort during endoscopy.

BACKGROUND: Laparoscopic surgeons who regularly perform endoscopy are more likely to develop musculoskeletal disorders than other internal medicine specialists, a difference that attributed to repetitive movements, poor postures, and sub-optimal equipment design. OBJECTIVE: This study aimed to design, build, and evaluate an endoscope holder for reducing the static load applied by the weight of the endoscope, in order to reduce musculoskeletal disorders risk factors in the surgeon's hand, shoulder and back issues regions. METHODS: A new endoscope holder was designed according to ergonomic design principles. The designed holder was evaluated by surface electromyography (sEMG) and discomfort assessment including 15 laparoscopic surgeons. The results were analyzed with centrality statistics and compared with the independent t-test using SPSS version 22. RESULTS: The evaluation of the new endoscope holder shows a statistical significant decrease in the average electrical activity of biceps brachii, triceps brachii, lateral deltoid, T9 Thoracic erector spinae, L4 Lumbar erector spinae, and external oblique after using the holder (p < 0.05). CONCLUSION: The results shows that using the new endoscope holder is associated with a lower level of discomfort, as well as a lower induced muscle activity. The results also highlight the need to upgrade the holder to offer rotability in all directions (perpendicular to the ground) which will be included in the next design.

An assessment of noise exposure and hearing health status among auto body workers in Kermanshah, Iran.

BACKGROUND: Unwanted sound is recognized as the most extensive source of contaminant in the workplace. Exposure to intense, continuous, and higher than 85 dB level noise can lead to noise-induced hearing loss. The aim of the present study was to determine the level of noise exposure and its impact on hearing health among auto body workers. MATERIALS AND METHODS: This descriptive-analytic study was conducted in 2020 to investigate the hearing health status of workers in auto body workshops. Sixty-one participants were randomly selected for audiometric testing. The equivalent sound level (Leq) of the workers was measured using a Casella CEL-320 noise dosimeter. Audiometric testing was performed using an AC40 audiometer. The mean hearing threshold levels (HTLs) of both ears were calculated for different frequencies. The results obtained were analyzed using SPSS v21.0 at a significance level of 95%. RESULTS: The participants had an average age of 35.5 ± 11.8 years and an average work experience of 16.5 ± 9.8 years. The mean Leq was 92.3 ± 4.7 dB. The mean HTLs for the right ear and left ear were 20, 15, 17.6, 19.2 dB, respectively with the right ear suffering more loss. A significant relationship was found between hearing loss in both ears (P < 0.001). The highest prevalence of hearing loss in both ears was observed at a frequency of 4 kHz. About 73.8% of the subjects had a normal HTL, 23.3% had mild hearing loss, and 3.3% had severe hearing loss. With increasing work experience, HTLs also increased significantly, particularly at 2-8 kHz. CONCLUSIONS: Chronic exposure to noise pollution threatens hearing health. Therefore, it is necessary to raise the level of awareness among workers in order to enable better hearing health protection and also to promote the use of hearing protection devices.

Training needs assessment of intensive care nurses in Zabol University of Medical Sciences' Hospitals.

BACKGROUND: The improvement of the knowledge, skill, and attitude of nurses working at the intensive care unit (ICU) through implementing training need assessment and holding continuous in-service training courses are of main requisites for providing better health services to the community. Based on this, in the present work, we are looking for the identification and prioritization of the training need of intensive care nurses in the Zabol University of Medical Sciences' hospitals. MATERIALS AND METHODS: As a cross-sectional, descriptive study, including two phases of identification and prioritization of training needs of ICU nurses, it was conducted by a close-ended researcher-made questionnaire for collecting the data on training needs from the viewpoint nursing officials, supervisors, and head nurses of the ICU wards in the first phase and a multiple-choice scientific test plus a checklist for measuring the knowledge and skill of the nurses in the ICU in the second phase. In both phases, census method was used for collecting the data. The validity and reliability of data-gathering tools, mentioned above, were tested and verified before gathering data. Data were analyzed with the descriptive statistics. RESULTS: The results indicated that ventilator setting according to arterial blood gas sampling and interpretation (77.81), cardiac monitoring, detecting dysrhythmia and taking immediate intervention (73.04), ventilator setting according to patient's respiratory status (68.61), airway management, oxygenation and intubation (64.39), and adults cardiopulmonary resuscitation (61.77) were the high-priority training needs of the nurses successively. CONCLUSION: To improve the quality of training programs and upgrading the knowledge, skill, and attitude of nurses working at ICU, the significance and the weight of each training titles should be determined according to the standards and the continuous in-service training plan along with nurses' training needs and duties.

Analyses and anticipating the future trend of accidents in an electricity distribution company of Iran: A time series analysis.

BACKGROUND: Many work-related fatalities happen every year in electricity distribution companies. This study was conducted to model accidents using the time series analysis and survey descriptive factors of injuries in an electricity distribution company in Tehran, Iran. METHODS: Data related to 2010 to 2017 were collected from the database of the safety department. Time series and trend analysis were used for data analyzing and anticipating the accidents up to 2022. RESULT: Most of the accidents occurred in summer. Workers' negligence was the reason for 75% of deaths. Employment type and type of injuries had a significant relationship (p <  0.05). CONCLUSION: The anticipating model indicated occupational injuries are going to have an increase in the future. A high rate of accidents in summer maybe because of the warm weather or insufficient skills in temporary workers. Temporary workers have no chance to work in a year like permanent workers, therefore acquisition experiences may be less in them. Based on the estimating model, management should pay attention to those sectors of the company where most of the risky activities take place. Also, training programs and using personal protective equipment can help to protect workers in hazardous conditions.

Safety climate and related factors in rehabilitation nurses of hospitals in Iran.

BACKGROUND: Safety climate is a common insight of staff that indicates individuals' attitudes toward safety and priority of safety at work. OBJECTIVES: Nursing is a risky job where paying attention to safety is crucial. The assessment of the safety climate is one of the methods to measure the safety conditions in this occupation. The aim of this study was to assess the safety climate of rehabilitation nurses working in hospitals in Tehran. METHODS: This is a cross-sectional study which was carried out on 140 rehabilitation nurses selected from all hospitals and clinics in Tehran in 2019. To collect the required data, a two-section questionnaire was used. The first section was related to demographic factors and the second part (22 statements) was to measure the safety climate using nurses' safety climate assessment questionnaire. The collected data were analyzed by SPSS V16 using independent t-test, ANOVA, Kruskal-Wallis and Mann-Whitney U test at the 5% level. RESULTS: Findings showed that the total mean of safety climate was 3.06±0.56. According to the results, a significant difference was found between the positive and negative satisfaction of nurses with safety climates (P-value = 0.03), communication with nurses (P-value = 0.01) and supervisors' attitude (P-value = 0.02). Furthermore, a significant difference in safety climate between the individual with the second job and the individual without second could be observed (P-value = 0.01). CONCLUSIONS: The results indicated that the safety climate was not at an acceptable level. Thus, it is essential to introduce safety training courses (e.g. safety, work-rest balance, and so on) and to improve the safety performance at work.

Impact of two ergonomics training on prevalence of upper and lower extremity complaints among nurses.

BACKGROUND: Musculoskeletal disorders (MSDs) were known as one of the main occupational problems among health-care workers. However, we had some limitations and difficulties for transferring ergonomic concepts to the health-care workers, especially nurses due to heavy work task and insufficient time for that. This study compares the impacts of two ergonomic training methods (lecture and pamphlet) in nurses of an Iranian tertiary hospital on prevalence of their upper and lower extremity complaints. MATERIALS AND METHODS: In the present randomized clinical trial with parallel groups, 1140 nurses were randomly selected and allocated to the control and two interventional groups. In the interventional groups, nurses revived a training program and pamphlet as ergonomic training methods about work-related MSDs and related ergonomic concept to MSDs prevention and nurses in the control group, did not receive any ergonomic training methods. Upper and lower extremity complaints measure among study nurses with Nordic MSDs before 6 months and 1 year after trial intervention. Statistical analysis including the Kolmogorov-Smirnov goodness-of-fit, Chi-square test, and independent sample t-test was performed using SPSS version 22. A two-tailed P ≤ 0.05 was considered statistically significant. RESULTS: At the first and second parts of the study follow-up, the prevalence of upper and lower extremities significantly improved in the interventional groups in comparison with the control group. Moreover, between the two trial groups, the frequency of MSDs in upper and lower extremities significantly improved among nurses of the pamphlet group in comparison with the lecture group. CONCLUSION: Findings of the study showed that we can use pamphlet as a suitable tool for describing ergonomic concepts in comparison with lecture among nurses.

Ergonomic intervention to reduce musculoskeletal disorders among flour factory workers.

BACKGROUND: Work-related musculoskeletal disorders are the most common occupational health hazards. In the flour production industry, the fast pace of work, high frequency of repetitive movements, manual handling of loads, and awkward postures put a lot of pressure on the worker's body. OBJECTIVE: Given the high exposure of the workers of the flour production industry to ergonomic risk factors, this study aimed to reduce the rate of musculoskeletal disorders among a group of flour factory workers through ergonomic interventions. MATERIALS AND METHODS: This interventional study was performed using the census method on the eligible workers of a flour factory. An ergonomic intervention program was planned and implemented with the goal of reducing musculoskeletal disorders. The effectiveness of the program was evaluated by measuring the prevalence of musculoskeletal disorders before and six months after the interventions. RESULTS: Before the intervention, musculoskeletal disorders were most prevalent in the lower back, arms, shoulders, legs, thighs, knees, neck and wrists, respectively. Evaluation of the prevalence of musculoskeletal disorders after the intervention showed the positive effect of the ergonomic intervention program on musculoskeletal disorders in the neck, shoulders, lower back, thighs, knees, and legs (P < 0.05). CONCLUSION: Engineering and management interventions implemented in this study led to a significant reduction in the level of ergonomic risk factors and a reduced rate of musculoskeletal disorders among workers of different units in the flour factory.

Functional parameters, wrist posture deviations and comfort: A comparison between a computer mouse and a touch pen as input devices.

BACKGROUND: Performing common computer tasks such as pointing, clicking, and dragging requires repetitive movements that cause musculoskeletal disorders in the wrists and hands. Given the growing use of touch screens and touch pens, further studies on the ergonomics of these devices are needed. This study aimed to compare a touch pen and an ordinary computer mouse in terms of movement time, error rate, wrist posture, and comfort of use. METHODS: Performance parameters (movement time and error rate), wrist postures, and comfort when using a mouse and a touch pen were measured based on ISO 9241-9 standard with the help of 27 participants. For data analysis, paired t test was performed using SPSS version 22. RESULTS: Using the touch pen resulted in better performance parameters than using the mouse (p < 0.05). Wrist extension and flexion were lower when performing the task with the computer mouse than with the touch pen (p < 0.05). When using the touch pen to perform the task, ulnar deviation and radial deviation were lower (p < 0.05). The overall comfort was higher when using the mouse than the touch pen. CONCLUSION: Our results showed that the touch pen had better performance parameters than the ordinary mouse and also resulted in lower ulnar and radial deviations. Given the impact of habit and proficiency on users' comfort in using input devices, it is reasonable to expect users becoming more comfortable by using touch pens on the long term.

Saddle seat reduces musculoskeletal discomfort in microsurgery surgeons.

Background. Microsurgery is a surgical procedure requiring a high degree of precision and is commonly facilitated through the use of an intraoperative microscope. When operating the microscope system, the long-term posture leads to musculoskeletal disorders in surgeons, and seats are commonly employed to diminish these problems. The present study was conducted to evaluate musculoskeletal discomfort during work with a saddle seat in comparison with conventional seats for microscopic work. Methods. Two types of seats, a saddle and a conventional one, were evaluated for 73 microsurgical surgeons in terms of musculoskeletal discomfort. Corlett and Bishop's body part discomfort scale was used to assess musculoskeletal discomfort before and after working with the seats. Results. The highest amount of discomfort that microsurgical surgeons acquire in the workplace was focused on their neck, shoulders, arms and back. During work with a saddle seat, a significant reduction was found for discomfort values in the neck, shoulder, arm, back, elbow and forearm, as well as the whole body (p < 0.05). Conclusion. This study showed that the use of saddle seats provides a more appropriate physical posture at work, and can decrease musculoskeletal discomfort in different parts of the body of microsurgical surgeons.

Ergonomic design and evaluation of a diagnostic ultrasound transducer holder.

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) are injuries and disorders that affect the body's movement and musculoskeletal system. Awkward postures represent one of the major ergonomic risk factors that cause WMSDs among sonographers while working with an ultrasound transducer. This study aimed to design and evaluate a new holder for the ultrasound transducer. MATERIALS AND METHODS: In the first phase a new holder was designed for the transducer, considering design principles. Evaluation of the new holder was then carried out by electrogoniometry and a locally perceived discomfort (LPD) scale. RESULTS: The application of design principles to the new holder resulted in an improvement of wrist posture and comfort. Wrist angles in extension, flexion, radial deviation and ulnar deviation were lower with utilization of the new holder. The severity of discomfort based on the LPD method in the two modes of work with and without the new holder was reported with values of 1.3 and 1.8, respectively (p < 0.05). CONCLUSION: Overall, this study indicated that applying ergonomics design principles was effective in minimizing wrist deviation and increasing comfort while working with the new holder.

An ergonomic intervention to reduce musculoskeletal discomfort among semiconductor assembly workers.

BACKGROUND: Work-related musculoskeletal disorders (MSDs) and ergonomics-related injuries are the single largest category of workplace injuries and are responsible for almost 30% of all worker's compensation costs. Awkward working posture refers to positions of the body that deviate significantly from the neutral position while job tasks are being performed and it is the primary ergonomic risk factor for developing musculoskeletal discomfort. OBJECTIVE: This study was conducted among assembly workers of a semiconductor in Tehran province with the objective of implementing an interventional ergonomic program to minimize musculoskeletal discomfort. METHODS: This study that was conducted on 105 male assembly workers of a semiconductor industry based on a census method. The standardized Nordic Musculoskeletal Questionnaire (NMQ) was used to determine the prevalence of MSDs. Corlett and Bishop's body part discomfort scale (BPD) was applied to evaluate body discomfort before and after the intervention (using a magnifying loupes to improve visibility of the parts). RESULTS: The results of NMQ showed the highest rate of MSDs were in neck, shoulder, upper arm and lower back regions (more than 75%). After ergonomic intervention, significant decrements of discomfort was observed in neck, shoulder, upper arm, elbows, lower arm, lower back and whole body discomfort (p < 0.05). CONCLUSIONS: It can be concluded that using magnifying loupes reduced discomfort in different body regions and the whole body. A conclusion of this research is that ergonomic interventions can decrease MSDs of at risk body regions in the long term.

Ergonomic risk factors and musculoskeletal symptoms in surgeons with three types of surgery: Open, laparoscopic, and microsurgery.

Background: Musculoskeletal symptoms are the main cause of loss of working time, and increase in labor costs. Poor posture is the most important risk factor for work-related musculoskeletal symptoms. This study aimed at evaluating the role of ergonomic risk factors in different surgical (open surgery, laparoscopy, and microsurgery) in the frequency or resonance frequency of musculoskeletal symptoms. Methods: This descriptive-analytic study was conducted on 81 surgeons in a hospital in Tehran. In this study, the prevalence of musculoskeletal symptoms was evaluated using the Nordic Questionnaire. Moreover, Workplace ergonomic risk assessment method (WERA) was used to evaluate ergonomic risk factors in 3 types of open surgery, laparoscopy, and microsurgery. Results: The results revealed that the prevalence of musculoskeletal symptoms of the neck, back, shoulder, and arm is high in surgeons (over 75%). The mean final score of WERA was 40.11, representing the high risk of the 3 types of surgery for the prevalence of musculoskeletal symptoms. Results revealed that the prevalence of musculoskeletal symptoms in the neck, waist and wrists had a significant relationship with the body posture in the 3 types of open surgery, laparoscopy, and microsurgery (p<0.05). Conclusion: In the present study, the prevalence of musculoskeletal symptoms was high in the neck, waist, and hands surgeries. Depending on the type of surgery, teaching correct working methods, using proper seats and ergonomic equipment are the best strategies to reduce musculoskeletal symptoms in the surgical profession.

The effect of a multifaceted ergonomic intervention program on reducing musculoskeletal disorders in dentists.

Background: Work-related musculoskeletal disorders (WMSDs) are the most common occupational injuries in dentists. These disorders occur due to the specific characteristics of dentistry occupation such as the use of tools and instruments and awkward posture. The present study aimed at evaluating the effect of multifaceted ergonomic program on reducing musculoskeletal disorders in dentists. Methods: One hundred-two male dentists who worked in dentistry clinics of Tehran's hospitals participated in this interventional study. Participants were randomly divided into control (n=50) and intervention (n=52) groups. Dentists in the intervention group (n=52) underwent multifaceted ergonomic intervention program for 8 weeks and dentists in the control group (n=50) only received the measurements. The prevalence of musculoskeletal disorders was evaluated in each of the 2 groups at 3 time points before the intervention, 3, and 6 months after the intervention using the Nordic Musculoskeletal Questionnaire (NMQ). Paired t-test was used to compare the prevalence of musculoskeletal disorders before and after the ergonomic intervention program at the end of 3 and 6 months. Results: The results revealed that the prevalence of musculoskeletal disorders was reduced after the intervention in the neck, shoulder, arm, wrist, back, thigh, knees, and feet (p<0.05). On the other hand, the prevalence of musculoskeletal disorders increased in the control group in the neck, shoulder, arm, wrist, thigh, and knee, respectively. The survey results revealed that 98% of the participants agreed with this intervention program. Conclusion: The results of this study revealed that the multifaceted ergonomic intervention program, which included improving working conditions, identifying ergonomic risk factors, regular exercise, and discussion group meetings, could decrease the prevalence of musculoskeletal disorders in dentists.

The effect of magnification lenses on reducing musculoskeletal discomfort among dentists.

Background: Work-related musculoskeletal disorders are the most important problems in the health workforce. These discomforts cause many working days losses, increase absenteeism from work, and impose annual economic costs. Awkward posture is the most important factor among the risk factors for work-related musculoskeletal disorders. This study aimed at implementing an interventional ergonomic program to minimize musculoskeletal disorder among dentists. Methods: This semi- experimental study was conducted on 75 dentists of Milad hospital using a census method. The Nordic Questionnaire was used to determine the prevalence of musculoskeletal disorders. In this study, the intervention was to apply optical magnification lens whose impact on reducing musculoskeletal disorder had been previously investigated. Corlett and Bishop Scale was used to evaluate musculoskeletal disorders before and after the intervention. Paired t-test was conducted to compare the discomfort intensity before and after the intervention. Results: The results revealed that the prevalence of musculoskeletal disorders in neck, back, shoulder, and arm were higher than other areas of the body in dentists. There was a significant difference in discomfort intensity of the neck, shoulder, arm, back, elbow, forearm, and the whole body after the ergonomic intervention (p<0.05). Surveys on improving working conditions using the magnification lens revealed that more than 89% of the individuals expressed that the use of the lens increased the ease while working. Conclusion: The present study revealed that the use of optical magnification loupes, because of providing a suitable posture while working, could reduce musculoskeletal disorders in different areas of the body. Thus, we can predict that the prevalence of musculoskeletal disorders will be reduced in dentists in a long run if they use optical magnification loupes.

Assessment of functional parameters and comfort of a new computer mouse as compared with other types of input devices.

BACKGROUND: This study was conducted to assess functional parameters and comfort of a new computer mouse (Ergomice) as compared with three other input devices. MATERIALS AND METHODS: Functional parameters (i.e., task completion time and error rate) of each device were assessed by 10 participants using standardized software based on Standard No. ISO 9241-9:2000. Comfort evaluation was also undertaken for each device using the visual analogue scale technique. Statistical analysis including the Wilcoxon signed-rank test and the Friedman test was performed using SPSS version 16. RESULTS: The functional parameters of the standard mouse were better than those of the other devices. However, no significant difference was observed between this mouse and Ergomice. Overall comfort evaluation showed that the standard mouse and Ergomice were more comfortable to work with. The comfort level of hand/wrist posture in the Ergomice was higher than that of the other three devices. CONCLUSION: The design features of Ergomice could improve its functional properties. Hand/wrist posture comfort of Ergomice was judged to be high compared with that of the other devices.

The comparison of Neoprene palumbo and Genu direxa stable orthosis effects on pain and activity of daily living in patients with patellofemoral syndrome: a randomized blinded clinical trial.

BACKGROUND: Patellofemoral pain syndrome (PFPS) is one of the most common disorders of the knee. Conservative approaches, as well as surgery, can decrease pain and the syndrome's progress effectively. OBJECTIVE: The aim of this study was to determine the effectiveness of neoprene palumbo orthosis (NPO) and Genu direxa stable orthosis (GDSO) on pain and the activities of daily living (ADL). METHODS: Thirty patients (males, ages 18 to 40) participated in this randomized blinded clinical trial. All of them were diagnosed with patella femoral pain syndrome. The participants were divided randomly into two groups of 15, with one group using neoprene palumbo (intervention group) and the other group using Genu direxa stable orthoses (control group). Using the Visual Analogue Scale (VAS) and the Knee injury and Osteoarthritis Outcome Score (KOOS), pain intensity and activities of daily living (ADL) and joint stiffness were analyzed before treatment and after three weeks of treatment. Data were analyzed using paired samples t-test and independent samples t-test. RESULTS: Both orthoses reduced the patients' pain. Both group showed meaningful improvement in pain reduction and ADL increase after using orthosis in each group. In comparing the variables, no significant differences were found between pain severity and ADL (p = 0.592, p = 0.887). In both groups, the mean of pain severity was different before, during, and after using orthosis (p < 0.05). CONCLUSION: The results of this study indicated that Neoprene palumbo and genudirexa stable orthoses improved the signs of patello femoral pain syndrome, including pain intensity and ADL.

Designing a new computer mouse and evaluating some of its functional parameters.

BACKGROUND: This study aimed to design a new mouse and evaluate some of its functional parameters. The prototype of an ergonomic mouse was made according to design principles. METHODS: The study was conducted from 2011 to 2013 in the Department of Ergonomics in Shiraz University of Medical Science. Functional parameters including Movement Time (MT) and error rate of the new mouse were evaluated by 10 participants based on ISO 9241-9 standard. RESULTS: The application of design principles in the new mouse resulted in improving MT and error rate so that they could be comparable to those of a standard mouse. MT, in both the standard and the new mouse was 0.846 and 0.864 s, respectively. Error rate of the standard and the new mouse was reported as 13% and 19%, respectively. Statistical analysis showed no significant difference between the two mice from these perspectives. CONCLUSIONS: Apparently, the studied functional parameters of the new mouse were similar to those of the standard one. The new mouse could be an appropriate substitution for the standard mouse without losing its positive characteristics.

Novel paint design based on nanopowder to protection against X and gamma rays.

BACKGROUND: Lead-based shields are the standard method of intraoperative radiation protection in the radiology and nuclear medicine department. Human lead toxicity is well documented. The lead used is heavy, lacks durability, is difficult to launder, and its disposal is associated with environmental hazards. The aim of this study was to design a lead free paint for protection against X and gamma rays. MATERIALS AND METHODS: In this pilot st we evaluated several types of nano metal powder that seemed to have good absorption. The Monte Carlo code, MCNP4C, was used to model the attenuation of X-ray photons in paints with different designs. Experimental measurements were carried out to assess the attenuation properties of each paint design. RESULTS: Among the different nano metal powder, nano tungsten trioxide and nano tin dioxide were the two most appropriate candidates for making paint in diagnostic photon energy range. Nano tungsten trioxide (15%) and nano tin dioxide (85%) provided the best protection in both simulation and experiments. After this step, attempts were made to produce appropriate nano tungsten trioxide-nano tin dioxide paints. The density of this nano tungsten trioxide-nano tin dioxide paint was 4.2 g/cm(3). The MCNP simulation and experimental measurements for HVL (Half-Value Layer) values of this shield at 100 kVp were 0.25 and 0.23 mm, respectively. CONCLUSIONS: The results showed the cost-effective lead-free paint can be a great power in absorbing the X-rays and gamma rays and it can be used instead of lead.

Analysis of electrical accidents and the related causes involving citizens who are served by the Western of Tehran.

BACKGROUND: Electrical burns account for a significant percentage of fatal accidents. Each year, a number of consumers in Iran suffer from electrical injuries due to technical problems, equipment failures, and the unauthorized use of electricity. The aim of this study was to examine the root causes of accidents that involved electricity in the district served by the Western Tehran Province Electricity Distribution Company. METHODS: This was a descriptive study in which incidents involving electricity-related injuries were investigated among customers served by the Western Tehran Province Electricity Distribution Company. Therefore, we collected and analyzed incident reports filed by citizens from 2005 through the first half of 2009 in the Distribution Company's coverage area, including Savejbolagh, Shahriyar, eastern Karaj, Qods City, southern Karaj, western Karaj, Malard, and Mehrshahr. The reported events were analyzed using SPSS software. RESULTS: Exposure of electricity lines and unauthorized construction of residential houses in areas where there were medium- and low-voltage lines were responsible for 37% of the injuries. The findings showed that the highest rate of accidents occurred in 2008 and the first half of 2009. The highest rate of accidents occurred among people with a mean age of 35. CONCLUSION: The results from investigating the causes of electrical accidents emphasized the necessity of developing a culture of safety in communities, especially among employees who are engaged in occupations related to electricity, construction workers, and school children to reduce the rate of such accidents.