Marziye Abbassinia, Farogh Mohammadian, Mohammadreza Monazam, Somaye Mahmoodkhani , Mahdi Asghari, Navid Ghaemian,
Volume 4, Issue 4 (Occupational Medicine Quarterly Journal 2013)
Abstract
Background: High levels of fatigue in the workplaces can lead to reduced productivity, and increase the risk of accidents and injuries. Purpose of this study was to assess and compare the fatigue levels among fixed-dayshift and rotating-shift workers of a rolling mills and steel production company in tehran.
Methods: The study included 180 workers with fixed- and rotating-shift schedules. The method involved in our survey data collection was using standard questionnaires by face-to-face surveys.
Results: Results showed that maximum level of fatigue for both groups is 4. Fatigue level between fixed-day shift and rotating-shift workers was statistically significant the degree of fatigue was higher in rotating shift workers. All symptoms associated fatigue in rotating shift workers were more severe than other, and statistically was significant. Comparison between tasks showed the most exhausting task is warehouse.
Conclusion: Results show that level of fatigue is high in the company's personnel, so adopting proactive measures such as reducing working hours, doing regular rest and exercise during working time, paying sufficient attention to humanitarian needs and improving work system can be helpful.
Majid Motamedzade, Payam Amini, Mahdi Mohammadian Mastanabad,
Volume 8, Issue 3 (Occupational Medicine Quarterly Medicine 2016)
Abstract
Introduction: Protective clothes are among the basic needs of firefighters against their occupational risks. Combination of heat stress effects caused by muscle activation and protective clothing, result in a high level of strain in the regulating system of body temperature. The aim of this study was to evaluate the practical cooling method of hand and forearm immersion in water.
Methods: In this study, fourteen professional firefighters were assessed. Each fire fighter wore protective clothing and heart rate, core body temprature and skin temprature were measured in sitting position. Then each subject walked on a treadmill in two 20-min bouts (5 km/h, 7.5% gradient) separated by a 15-min recovery period, during which firefighters were cooled (case) via application of hand and forearm water immersion and remained seated without cooling (control). During exercise and recovery time, firefighters, physiologic parameters (heart rate, core body temperature and mean skin temperature) were measured and recorded every five minutes.
Results: The results of marginally modeling of longitudinal responses using generalized estimating equations method showed that paremeters of heart strain (core body temprature, skin temprature and heart rate) were significantly reduced after intervention (p<0.05).
Conclusion: In situations that intense fire actions must be faced, the cooling strategy of dipping hands and forearms in water could be considered as an effective and simple method in comparison to other cooling strategies.
Mojtaba Zokaei, Farough Mohammadian, Mohammad Javad Jafari, Abolfazl Takalou Bighash,
Volume 15, Issue 4 (Occupational Medicine Quarterly Journal 2023)
Abstract
Noise is one of the most important environmental stressors, which, along with the prevalence of exposure in the work and living environment, has various effects. Noise exposure can create positive or negative consequences at different levels. Based on this, in the present study, brain wave changes in exposure to different levels of noise were investigated.
In this experimental study, 72 student volunteers with an average age of 26.27 years old, participated in this study after meeting the exclusion criteria and receiving sufficient training regarding the implementation procedure. Before starting the test, demographic questionnaires, noise sensitivity, and audiometry were completed for the participants. For exposure, a noise level of 45 dB was chosen as the background sound, and three levels of 75, 85, and 95 dB were selected for exposure. The participants were exposed to the determined facial pressure level for half an hour and rested for half an hour after that. During exposure to the noise, the brain waves of the volunteers were used by the portable EEG device Ewave, 16 channels. And the results were analyzed by the mat lab v12 software.
The results of the study show that exposure to two levels of 75 and 85 dB of absolute power alpha has increased in 14 brain channels, including CZ and O2 channels. The results showed that the noise level of 75 dB compared to the background state did not change significantly in any of the channels (P>0.05). At the level of 85 and 95 dB, the absolute power of the beta frequency band has increased. At the level of 95 dB, this increase is statistically noticeable and significant in almost all brain regions (P<0.05).
Based on the results of this study, it can be said that exposure to noise causes changes in neuronal activities in the brain, and this can affect the performance of the exposed workers.
