نورالدین قراری

During the Covid-19 epidemic, the armed forces and medical personnel, took direct action against the disease and served the people. It is possible that these forces and their mental health were affected by the outbreak of this disease. This study aimed to investigate the prevalence of COVID-19 among the armed forces and its impact on their mental health.

This study is a systematic review based on the MOOSE checklist. This study thoroughly reviewed related articles in valid databases from 2019 to 2021. In order to extract the required data, the titles, abstracts, results, and all texts of the articles have been reviewed. In order to evaluate the quality of the reviewed articles, the JBI checklist was used. Finally, 15 articles were reviewed based on the purpose of the study and keyword search.

According to the articles, COVID-19 has been highly prevalent among military personnel, while it was not prevalent among Navy personnel. Factors such as inadequate training and poor nutritional status have led to the spread of COVID-19 among armed forces personnel. Furthermore, the mental health of armed forces personnel has also been affected by the outbreak of COVID-19. Depression and anxiety have increased among this military personnel, especially physicians and military veterans. COVID-19 obsession has increased the fear, anxiety, stress, and depression of the armed forces. The duration of sleep and its quality, type of occupation, and age were among the factors that affected the mental health of military personnel during the COVID-19 epidemic.

The spread of COVID-19 among the armed forces can be prevented by taking appropriate initial control measures, training armed forces personnel, and paying attention to personnel's environment and nutrition status. To some extent by conducting psychometric tests of Armed Forces personnel, the impact of the COVID-19 outbreak on personnel's mental health can be prevented.

Harmful factors in the workplace such as noise and heat stress can have adverse effects on muscle activity. This study was performed to investigate the effect of simultaneous exposure to noise and heat stress on the activity level of biceps and flexor muscles.

This experimental study was performed on 24 male students in laboratory conditions. Participants in three groups exposure to SPL of 75, 85 and 95 dBA and WBGT =22, 30 and 35°C randomly. During light manual activity, the activity level of biceps and flexor muscles was measured in a sitting manner using surface electromyography. Normalized RMS (Root Mean Square) of muscles was used to compare the level of muscle activity in different conditions. ANOVA test was used to examine the relationship between variables.

The mean (SD) age of the study participants was 21±1.6 years. Based on the muscle activity WBGT=30°C and SPL=85 dB were defined as border points in changes of biceps activity. The highest and lowest levels of flexor muscle activity were observed at SPL of 75 and 95 dB, respectively. The interaction between noise and heat stress exposure show that exposure to both factors causes significant changes in muscle activity levels (P.value<0.05).

Exposure to noise and heat stress in the workplace affects the function of the biceps and flexors muscles. To more accurately determine the effects of noise exposure and heat stress on muscle activity, further studies are recommended.

Considering the importance of implementing occupational safety and health management systems for the prevention of various diseases in the workplace, as well as determining the notability and role of induction and implementation of occupational health management systems in controlling and reducing COVID-19 outbreak in work environments, as one of the most sensitive and important of society sectors, this study aimed to compare the prevalence of Covid-19 disease in two groups of industries with and without occupational health management systems and related management risk factors in several industries, in Iran.

This cross-sectional study was performed in May 2020 during the outbreak of coronavirus in some industries under Shahid Beheshti University of Medical Sciences’ supervision. During the present study, 70 industries included 24 industries active in chemical products, 6 industries of automotive parts manufacturing, 14 industries of home appliance manufacturing, 16 industries of health and cosmetics products, 4 industries of metal products, and six service companies were studied. The studied population included two industries with an occupational health management system (33 industries) and industries without an occupational health management system (37 industries). In this study, a checklist was designed to collect study data based on the requirements and parameters of occupational health management systems, as well as information related to infectious diseases such as COVID-19, which included information on COVID-19 disease in two groups of studied industry, occupational medicine, biological hazards risk management, occupational health information management system, training, and employee participation, as well as the management parameters of COVID-19 outbreak. Statistical analysis of the study data was performed using the Chi-square test and Fisher’s exact test by SPSS. 23 software.

The number of workers working in the two groups of industries with and without occupational health management systems was 673 and 708, respectively. Among 33 industries with occupational health management systems, 12.1% industries had health, safety, and environment management system (HSE-MS), 66.7% industries had OHSAS 18001:2007 standard, and 21.2% industries also had ISO 45001:2018 certification. It was found that the prevalence of Covid-19 disease in those industries without occupational health management systems was significantly higher (p <0.05). It has been found that Covid-19 outbreak in industries without occupational health management systems was significantly higher (p<0.05). The findings also showed that there was a significant difference between the parameters of occupational medicine, risk management of biological hazards, occupational health information management system, training and employee participation, as well as the management parameters of COVID-19 disease in the two groups of studied industries (p<0.05).

The findings of the present study indicated that there was a significant relationship between the scores of occupational medicine parameters and occupational health information management system, risk management of biological hazards, training and employee participation, management of COVID-19 and finally the prevalence of the disease among industries with or without occupational health management system. So, implementation and establishment of occupational health management systems can be an effective step in reducing the prevalence of viral and infectious diseases such as COVID-19.

Different methods can be used for ventilation of tunnel during construction. Each method has advantages، limitations، and disadvantages that should be considered in selection of methods. Inefficient ventilation can lowered production rate and provide undesired work conditions for employees. This issue is critical in gaseous tunnels and may imperil the workers lives and the whole project. This paper presents a series of guidelines for selection of ventilation system، optimal implementation، and aspects of ventilation system design in gaseous tunnels based on common ventilation standards. Common ventilation systems in tunnels during construction were compared for selection of Alborz tunnel ventilation system. Air-supply ventilation system was selected as the best design. Whereas air-supply ventilation system may be applied in different forms، six distinct designs were compared for Alborz tunnel. In order to determine tunnel ventilation capacity، air volume required was calculated based on different criteria. Air volume required for diesel equipment was considered as the air requirements of tunnel ventilation. Considering advantages، disadvantages، and limitations of the small and large diameter channel applications، ventilation system calculations were conducted for the diameters 100، 140، and 180 cm to select optimum size. The results from comparison of different ventilation variants showed that using two parallel jet fans on tunnel surface in a joint canal (140 cm) is the most appropriate design for tunnels with these characteristics. Poor ventilation is a critical factor in deep underground and gaseous tunnel drilling and improper ventilation may substantially affect the work environment، life، and production rate.