Effect of Lipid Profile Parameters on Noise Induced Hearing Loss.

Background: Noise induced hearing loss (NIHL) is an irreversible occupational disease among industrial workers. Recent studies have reported that changes in some metabolic factors such as the serum level of sugar and lipids might have a role in suffering from NIHL among workers exposed to noise. We designed this study to assess the association between lipid profile changes and NIHL occurrence among noise-exposed workers. Methods: This case-control study has been conducted according to noise-exposed workers registry data in one of the Iranian automobile factories between 2007 and 2017. We classified study workers into the NIHL and control groups. We assessed the impact of lipid profile parameters across the study groups using the independent samples t-test, chi-square, and regression. Results: The mean serum level of cholesterol was significantly higher in the NIHL group than in workers of the control group (215.27 ± 60.30 vs 204.49 ± 63.69 mg/dL; P = 0.041). Moreover, the serum level of HDL was significantly lower in workers in the NIHL group compared with the control group (35.21 ± 6.87 vs 37.43 ± 7.28 mg/dL; P < 0.001). Although other lipid profile parameters (LDL, TG, LDL/HDL ratio) were higher among workers of the NIHL group, their differences were not significant. Conclusion: A cholesterol level lower than 200 mg/dL is known as a protective factor and an HDL level lower than 40 mg/dL is an NIHL risk factor. More attention should be paid to controlling serum levels of cholesterol and HDL.

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.

Assessment of Pulmonary Function Parameters, Signs, and Symptoms in the Employee of a Dairy Products Company in Tehran, Iran.

BACKGROUND: Workers in dairy products companies are exposed to different respiratory hazards. The current study aimed at investigating and comparing the prevalence of pulmonary function parameters, signs, and symptoms in the exposed workers and office staff. MATERIALS AND METHODS: The current cross sectional study was conducted in 2015 on 864 employees working in a dairy products company in Tehran, Iran. The subjects included 646 employees exposed to respiratory hazards at the production line and the other group consisted of 218 staff not exposed to respiratory hazards in the production line as the unexposed group. Demographic characteristics and the presence of respiratory symptoms and signs were gathered using a checklist. Spirometric indices including FEV1, forced volume vital capacity (FVC), and FEV1/FVC were measured for the study participants. RESULTS: Although exposure to the respiratory hazards among participants of the exposed group was lower than permitted limits, the frequency of respiratory signs and symptoms were significantly higher than those of the unexposed staff. In the current study, mean percentage of FVC, FEV1/FVC, and FEV1 were significantly less than the predicted amount in the exposed group than in the unexposed group. CONCLUSION: Although the frequency of respiratory signs and symptoms was lower than those of other similar studies, abnormal spirometric patterns were common; hence, it can be pointed out that even in the work environments, such as dairy products industry with below the permissible exposure limit of respiratory risks, multiple spirometric disorders can be observed. In other words, the absence of respiratory signs and symptoms are insufficient and application of different pulmonary function tests, such as spirometry, seem essential for assessment.

Occupational Class Groups as a Risk Factor for Gastrointestinal Cancer: A Case-Control Study.

BACKGROUND: Cancer has a high mortality rate in both developing and developed countries. 11%-15% of cancers are attributable to occupational risk factors. OBJECTIVE: To determine if specific occupational classes, based on the International Standard for Classification of Occupations 2008 (ISCO-08), are risk factors for gastrointestinal (GI) cancer. METHODS: In this case-control study, 834 cancer patients were interviewed by a single physician. Cases included patients with GI cancer. Age-matched controls were selected from non-GI cancer patients. Each year of working, up until 5 years before the diagnosis, was questioned and categorized by the ISCO classification. RESULTS: 243 GI cancer cases and 243 non-GI cancer patients (486 in total) were studied. Working in ISCO class 8 (plant and machine operators, and assemblers) was significantly associated with higher risk of GI cancer (OR 1.63, 95% CI 1.05 to 2.52). Working in ISCO class 6 (skilled agricultural, forestry and fishery workers) and 9 (elementary occupations) were also associated with higher incidence of GI cancers. CONCLUSION: Working in ISCO classes of 8, 6, and 9, which are usually associated with low socio-economic status, can be considered a risk factor for GI cancers.

Assessment of Pulmonary Function Parameters and Respiratory Symptoms in Shipyard Workers of Asaluyeh City, Iran.

BACKGROUND: Workers in shipyard companies are exposed to different respiratory hazards. The present case-control study was designed to evaluate pulmonary function tests and respiratory symptoms among shipyard workers in Asaluyeh city in Southwest Iran. MATERIAL AND METHOD: Between March and October 2015 we recruited participants from two separate populations: shipyard workers as cases and office workers from the same shipyard company, who are not exposed to the same respiratory hazards, as controls. History was obtained from all participants and they all underwent physical examination and spirometry. RESULTS: Respiratory signs and symptoms were present in a significantly higher number of shipyard workers compared to the unexposed office workers. Similarly, there were significant spirometric differences between cases and controls. CONCLUSION: It seems that workplace hazards play a more significant role than other factors such as air pollution in development of respiratory diseases, and future studies for investigating respiratory symptoms, pulmonary function parameters, biological monitoring and measurement of respiratory hazard need to be performed.

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.

The role of ergonomic training interventions on decreasing neck and shoulders pain among workers of an Iranian automobile factory: a randomized trial study.

BACKGROUND: Ergonomic training had been implemented for prevention or reduction of neck and shoulder complaints among workers. The purpose of the present study was to assess the role of ergonomic training intervention on decreasing the prevalence of neck and shoulder complaints among workers of an automobile factory. METHODS: Within the present randomized clinical trial, the role of three ergonomic training methods on the prevalence of neck and shoulders pain among 503 workers of an automobile factory (Response rate: 94.23%) was assessed. The eligible workers were randomly allocated into the following three interventional (pamphlet, lecture, workshop) groups and one control group. The Nordic questionnaire was used to assess the prevalence of neck and shoulder complaints. We followed and assessed the prevalence of neck and shoulders complaints among the study employees before and one year after the intervention. We used chi-square and Mann-Whitney tests to compare the prevalence of neck and shoulder complaints between the trial and control groups. A two-tailed P-value less than or equal to 0.05 was considered statistically significant. RESULTS: The prevalence of neck and shoulders complaints among the study employees at the recent week (p= 0.002) and year (p= 0.02) had been significantly decreased in the study employees after participating in the study workshop. The prevalence of neck and shoulders complaints at the recent week and year did not significantly changed in the study employees after receiving the pamphlet and lecture as ergonomic trainings. CONCLUSION: Workshop as an ergonomic training method had an effective and powerful role on decreasing the prevalence of neck and shoulders complaints among workers.

The effect of physical and psychosocial occupational factors on the chronicity of low back pain in the workers of Iranian metal industry: a cohort study.

BACKGROUND: Low back pain (LBP) is one of the most common problems among the workers of different industries. The role of occupational factors in causing the LBP has been indicated previously. LBP has great socio-economic costs and most of its costs are related to the chronic LBP. The aim of this study was to identify the occupational risk factors that are related to the progression of the LBP from acute to chronic phase. METHODS: This cohort study has been conducted on 185 workers with acute LBP. Information related to their occupational exposure at baseline has been measured with a valid questionnaire using the self-report approach. Patients follow up was done monthly for three months after the start of the pain. Those workers whose occupational exposure had not changed during the follow up were divided into two groups of chronic LBP (n = 49) and cured (n = 136) according to the duration of the pain period (more or less than 3 months), and their job exposures were compared. RESULTS: Among the physical and psychosocial risk factors, social support (OR= 0.466, CI= 0.231- 0.940) and job satisfaction (OR= 0.455, CI= 0.232-0.891), and lifting weights more than 15kg (OR=2.482, CI= 1.274-4.834) indicated a significant relationship with the chronicity of the LBP. After putting the variables into the regression model, only lifting>15kg remained statistically significant. CONCLUSION: According to the observed relationship between these occupational risk factors (social support, job satisfaction, lifting>15kg) and the chronicity of the LBP, there is hope that eliminating these factors in the workers with acute LBP will prevent its progression to the chronic phase.