ameneh jari

Even in an era of automation and digitalization, Manual Material Handling (MMH) can be called the most common industrial task. The aim of this study was to evaluate the prevalence of musculoskeletal disorders (MSDs) induced by manual handling tasks on the workers of a printing factory in Tehran in 2017 and then to evaluate the effectiveness of a training intervention based on health promotion.

This study had quasi experimental design and was conducted on 40 men. First, demographic data were collected and the Nordic questionnaire was used to determine the prevalence of MSDs in workers. Then, MMH tasks were assessed using Manual Handling Assessment Chart (MAC). A short training course was designed to promote health. Finally, the same MMH tasks were re‑evaluated 3 months after the training intervention.

Among the various tasks, the highest prevalence of work‑related MSDs (WMSDs) was observed in the lower back (77.5%) and shoulder (62.5%). Based on the final scores of the MAC method, the jobs that received the highest scores were cutting (individual lifting), with 22 scores and action level “immediately necessary,” cutting (individual load carrying), with 15 scores with action level “urgently needed.” Arranging the forms (individual lifting) received a similar score. After the training intervention, the estimated risk level reduced by 12, 9, and 6 points, respectively, reaching a safe action level, i.e., “necessary in the future.”

The results demonstrated that educational interventions might be equally effective in low‑technology work environments. More in general, the MAC method can be used to make informed planning of educational interventions against WMSDs risk in MSDs. This health promotion approach is critical for care of human recourse.

Little attention has been paid to the effects of combined exposure to noise and vibration. Exposure to noise and vibration can effect stress hormones and may lead to high blood pressure and cardiovascular disorders. This study aims to investigate the effects of noise and vibration on urinary Metanephrine and Normetanephrine among men.

In this experimental study, 30 male students were deemed eligible for entry. Background variables such as temperature, light intensity, sound pressure level and vibration acceleration (before and after exposure) were measured throughout each experiment. Participants were randomly exposed to two noise levels and two vibration accelerations for 30 minutes in a combined and independent exposure condition. Urine samples were taken an hour before and an hour after exposure. Metanephrine and Normetanephrine levels were measured using the ELISA method and a specialized Metanephrine/Normetanephrine urinary measurement kit. A repeated measures regression with a Generalized Estimating Equations (GEE) approach was applied for data analysis.

The exposure to noise (at 85 and 91 dB(A)) and independent exposure to whole body vibration at 1.85 m/s2 caused an increase in Normetanephrine and a decrease in Metanephrine concentration although these changes were not statistically meaningful (P>0.05). Combined exposure to noise and vibration caused an increase in Metanephrine and Normetanephrine concentration. These changes were also not statistically significant (P>0.05).

Study subjects’ stress hormone concentrations changed when exposed to noise but did not follow a particular trend. Short term exposure (30 minutes) did not have a distinguish effect on urinary Metanephrine and Normetanephrine concentrations. Therefore, urinary Metanephrine and Normetanephrine concentrations cannot be considered appropriate indicators for noise and whole body vibration exposure.

Musculoskeletal disorders in kitchen workers are prevalent due to the nature of work and repetitive work. But few studies have been done on this profession. The RULA procedure is one of the best posture assessment methods for assessing upper limbs. The aim of this study was to evaluate musculoskeletal disorders using RULA method among Gonabad kitchen workers.
In this descriptive analytical study, Work postures of 78 workers in all Gonabad kitchens and restaurants were recorded using the camera while working. And the most repetitive and awkward posture were chosen and analyzed using the RULA method. Data analysis was done using SPSS software and double-duplex scores were compared with R software (programming software).
The results showed that the highest postural score and level of actions at the workstations were earned at points 7 and 4 respectively which was related to the task of cleaning the kitchen. The duties of carrying the pot and pouring the material in the next ranks were high RULA privileges. The highest mean scores for each of the organs examined were neck, wrists, and trunks respectively. Also, 51.20% of all workers carried an average load of more than 11 kilograms. The highest loaded weight on duty carries the pot with an average of 30 kilograms. According to the study, 100% of Gonabad's kitchen postures should be improved.
In order to prevent musculoskeletal disorders, the correction of postures and the reduction of carried load are necessary. Since ergonomic studies on kitchen workers are very limited, it is suggested that further studies on ergonomic interventions, such as the design of workstations should be performed to correct postures of the neck, trunk, and wrists of workers.