Prevalence, incidence and associated factors of musculoskeletal disorders before and during the Covid-19 pandemic in faculty members: a comparative cross-sectional study.

BACKGROUND: The COVID-19 pandemic has led to the broad acceptance of distance education (DE), with university professors and students conducting the teaching-learning process remotely from their homes. The propose of this study to investigate the prevalence of musculoskeletal disorders (MSDs) before and during the COVID-19 pandemic and identify risk factors associated with DE that may contribute to an increased incidence of these disorders among university professors. METHODS: This cross-sectional analytical study took a comparative approach and involved 310 university professors in Iran. Data were gathered using an online questionnaire. Initially, demographic and occupational information of the professors, hours of physical activity, and hours spent using electronic devices were recorded. Participants were then asked to report MSDs in various body areas throughout the previous year and the previous seven days. Finally, MSDs risk factors such as workstation ergonomics during computer, laptop, smartphone, and tablet use, as well as working postures during online teaching or offline content development during the COVID-19 pandemic, were examined. RESULTS: The majority of the participants were male (66.13%), with a PhD (46.77%) and a faculty member position (74.2%). On average, the use of computers and laptops increased by 2.67 h and 2.72 h, respectively, during the pandemic compared to before the pandemic. This increase was statistically significant (P < 0.001). MSDs incidence increased significantly before and during the COVID pandemic was observed in the areas of the neck, shoulders, lower and upper back, arms, forearms, wrists and fingers (P < 0.05). The highest cumulative incidence (Cin) of MSDs was related to the neck (Cin = 24.20%), upper back (Cin = 21.29%), low back (Cin = 18.06%) and fingers (Cin = 16.13%). The prevalence of MSDs during the COVID pandemic was significantly associated with employment status (P = 0.042), work experience (P = 0.016), age (P = 0.027), increase in the use of computers/ laptops (P < 0.001), decrease of the smartphone/tablet distance from the body (P = 0.047), workstation (smartphone-tablet, computer, laptop) (P < 0.05), head position (smartphone-tablet) (P = 0.029), display height (computer/laptop) (P = 0.045) and physical activity (P = 0.006). CONCLUSIONS: It appears that the increased duration of smartphone, computer, and laptop use, combined with decreased physical activity and detrimental changes in ergonomic conditions of workstations during the quarantine period caused by the COVID-19 pandemic, has resulted in a shift from dynamic to static tasks and an increase in the prevalence and incidence of MSDs among university professors.

Application of Multiple Occupational Health Risk Assessment Models for Crystalline Silica Dust among Stone Carvers.

OBJECTIVE: Silica is the most abundant substance on the Earth's crust and is a proven carcinogen. The aim of this study was to measure the occupational exposure of stone carvers to crystalline silica and to evaluate the health risks.  Methods: This descriptive and analytical cross-sectional study was performed on 79 stone carvers. Inhalation air sampling was performed by the NIOSH7500 method and the amount of silica was determined by X-ray diffraction (XRD). Semi-quantitative and quantitative risk assessments were performed using the methods of the Singapore Department and the US Environmental Protection Agency (EPA), respectively. Mortality due to silicosis and lung cancer were estimated using the Manettej and Rice models. Data were analyzed using SPSS23 software. RESULTS: The mean exposure to total inhalable dust and crystalline silica among the stone carvers was 1.44 and 0.5 mg/m3, respectively. Exposure to total dust and silica was significantly higher than the occupational standard (P <0.0001). Stone carvers' exposure to silica was at very high-risk level, and the carcinogenicity of silica considering two cancer slopes was 7.40 × 10-6 and 3.12 × 10-7 and the risk of non-carcinogenicity was unacceptable. CONCLUSION: The mortality rate due to silicosis was between 3 and 12 people per thousand, and due to lung cancer was 150.24 people per thousand. Based on the results of risk assessment, serious control measures should be implemented in order to reduce workers' exposure to silica.

Carcinogenic risk assessment and changes in Spirometric indices in casting and welding workers exposed to Metal fumes.

INTRODUCTION: The aim of this study was to investigate exposure to dust, and metal fumes, changes in pulmonary function indices among industrial workers to estimate the carcinogenic and non-carcinogenic risk of exposure to occupational metal fume.

Methods: This cross-sectional study was performed on 98 workers exposed to metal fumes. Air sampling was performed according to the NIOSH 0500 method and was analyzed by gravimetry and metal levels were analyzed by atomic absorption spectrometry. Spirometric results for 2010-2016 were collected. Carcinogenic and non-carcinogenic risk assessments were performed according to the US Environmental Protection Agency guidelines. Data were analyzed by SPSS 20 software. RESULTS: The mean occupational exposure of the subjects to workplace dust and iron fumes was 15.95 ± 6.65 mg/m3 and 13.18 ± 3.06 mg/m3 respectively. During these 6 years, the FVC (P=0.04), PEFR (P=0.04), and FEV1 (P=0.03) indices decreased significantly among welders, but there was no significant difference between FEV1/ FVC indexes. Also, the mean of FEV1 and PEFR decreased significantly amongst casting workers, but FVC and FEV1/ FVC had no significant difference. Multivariate regression showed that in both jobs, BMI and work history were related to pulmonary function indices. The mean total excess ifetime carcinogenic risk (ELCR) of hexavalent chromium in the study population was 0.708 per 1000 people and the mean non-carcinogenic risk of hexavalent chromium was HQ = 19.62. CONCLUSIONS: The results showed that exposure to metal fumes in casting and welding jobs reduces pulmonary function indices. Although the average occupational exposure to hexavalent chromium is lower than the recommended limit and the risk of carcinogenesis is within an acceptable range, the risk of non-carcinogenic effects among workers is significant Therefore, it is important to prevent this problem, by adequate ventilation and using respiratory masks.