اسماعیل کرمی

Although aluminum oxide nanoparticles (Al2O3-NPs) are the most widely used nanomaterials, limited studies have been reported on their toxicology. Therefore, the present study aimed to investigate the potential toxicity of aluminum oxide (alumina) nanoparticles and the protective role of aqueous extract of wormwood plant on nanomaterial-induced disorders in the lung of rats.

Here, 36 male Wistar rats were randomly divided into six groups. Next, the rats were first exposed to 200 mg/kg of the aqueous extract of wormwood plant (by gavage) for 15 days and then received a dose of 30 mg/kg of aluminum oxide nanoparticles as an intraperitoneal injection for 14 days. Furthermore, various features of clinical signs, body weight, biochemical parameters, gene expression changes, lung weight ratio, histopathological observations, and metal content in lung tissue were evaluated during the experiment. Eventually, the ANOVA (Analysis of Variance) and Tukey’s range test were employed to analyze and compare the mean of the data.

The results revealed that aluminum oxide nanoparticles at a concentration of 30 mg/kg body weight led to changes in antioxidant enzyme activities, e.g., T-SOD, CAT, GPx, and TAC, lipid peroxidation, and iNOS for exposed rats. Also, the above biochemical disorders were associated with altered expression of oxidative stress-related genes (HO-1, MT-1) and histological changes in the lung tissue. On the other hand, simultaneous intake of aqueous extract of wormwood plant and aluminum oxide nanoparticles in rats significantly improved the studied parameters (p <0.05).

Our findings showed that the γ-Al2O3 NPs were more toxic than α-Al2O3 NPs, which can be attributed to changes related to their size and shape characteristics. Also, it was observed that the wormwood plant could play a protective role against aluminum oxide nanoparticles-induced pulmonary toxicity in rats.

Over recent years, various programs have been conducted to reduce noise, indicating the increasing concerns of society over noise pollution. This study has been performed to enhance the performance of parallel barriers on two sides of a highway considering the surrounding buildings.

The 2D boundary element simulation method was employed to predict the noise reduction in barriers. Regarding the effect of buildings and water canals, various kinds of models were investigated to compare the effectiveness of different boundary barriers in real conditions from a listener’s perspective.

The use of a single YA model could improve the performance of parallel barriers by 3.5 dB compared to that of a TS model. Moreover, by using a pair of barriers, no significant change was observed in the performance of the second barrier. However, by using parallel barriers along the surrounding buildings, the TD model improved the efficiency by 3 dB compared to the TS model. The rise in the frequency resulted in remarkable adverse effects on the barrier performance, such that the surrounding buildings at a distance of 8 m had a negative effect on the performance of the parallel barriers by almost 8.34 dB.

In general, by ignoring the buildings, the use of a pair of TZ barriers showed a higher performance. Meanwhile, by considering the buildings in the design model, the TD model was found to be optimum. Therefore, it can be concluded that choosing an ideal barrier only based on the noise behind it cannot indicate its behavioral and acoustic characteristics in a real environment.

The COVID-19 pandemic significantly effects on health of workforce as the most important source of manpower in maintaining business and the community economy. Therefore, this study aimed to investigate the knowledge, attitudes and practices related to COVID-19 and its effective factors among industry practitioners in industrial areas.

A cross-sectional study was conducted in Tehran industrial city from October to December 2020. Data from 494 practitioner’s industry were collected through survey questionnaire including demographic and a 35-item questionnaire to assess the status of knowledge, attitude and practices to the COVID-19 prevention guidelines. The content validity of the questionnaire was confirmed by the experts of Occupational health and Epidemiology and performed by two relative content validity coefficients, the Content Validity Ratio (CVR) and Content Validity Index (CVI), which were 0.78 and 0.85, respectively. Additionally, reliability was proved through a pilot study to calculate Cronbach’s alpha and determined to be 0.81. Descriptive analyses and chi-square tests and Pearson rank correlation analyses were performed to determine factors associated with knowledge, attitudes, and practices towards COVID-19. Data analysis was performed using STATA software version 17 with a significance level of P <0. 05.

The mean and standard deviation of practitioner’s knowledge was 19.68 ± 3.55, their attitude was 14.74 ± 3.45 and their performance was 7.97 ± 0.91. Educational level (r=0.19, p=0.015) and marital status as employees (r=0.24, p=0.042) were directly correlated with attitude and practice, respectively. Also, the results of Pearson correlation test showed that there is a positive and significant correlation between knowledge and attitude (r = 0.11, P = 0.01) and attitude and practice (r = 0.98, P = 0.001).

The results of the present study showed the need to increase awareness through training courses and positive attitude of the studied practitioner in order to strengthen suitable practices and motivate them to take appropriate preventive measures against COVID-19.

Housekeeping is one of the occupations that have a variety of physical and psychological stresses. On the other hand, the prevalence of musculoskeletal disorders (MSDS) is intensified by factors such as high physical and mental workload. Therefore, this study was aimed in order to investigate the relation between prevalence of musculoskeletal disorders with mental workload and general health in housewives.

This descriptive cross-sectional study was carried out on 200 housewives by available sampling method. The Persian version of Nordic Questionnaire, Cornell (CMDQ), General Health (GHQ28) Mental workload (NASA-TLX) Questionnaire, were used for data collection.

Demographic characteristics showed that 90.5% of selected society are married, 62% had no university education and the average age was 42.33 ± 0.87 years. Interestingly, the results of this study show that, the highest prevalence of musculoskeletal disorders was found to be in the low back region (48%), followed by mean score of general health questionnaires (19.05± 8.34) and mental workload (52.16 ± 12.21). The result showed that there is a significant difference between musculoskeletal disorders with mental workload and general health.

Considering the role of housewives in human resource productivity, suggested that interventions to prevent MSDS and increase public health be considered by health authorities. Taking actions such as using the MSDS questionnaire, counselling, workshops, awareness sessions, posture correction and training on how to get things done, work-rest cycle program, diversification at work, and recreational programs can increase mental health, reduce mental workload and reduce musculoskeletal injuries.

The work process is very important in complex jobs, so that if you forget or do not do it for any reason, it will have unpleasant consequences. The aim of this study was to identify and evaluate the human errors in sensitive jobs from two perspectives of human error identification in a high-voltage post station.

In this descriptive study, TAFEI and SHERPA techniques were employed to identify the operator's error. The necessary information was obtained by directly observing the human activities, interviewing and reviewing the tasks and sub-tasks with HTA method. The exploited techniques were thence compared in terms of error detection and applied field.

The results of matrix table in the job task using TAFEI method showed 29 cases of illegal transfer, so 29 human errors were identified; while totally 25 errors were identified by SHERPA method.

The results of this study show that the TAFEI method performs better in identifying the number of human errors in the task sequence step. On the other hand, the SHERPA method can cover the weaknesses of the TAFEI method and provide the level of risk. Accordingly, it is recommended that the analyst consider the different available HEI techniques and apply the one that he/she considers the most suitable for their need.