Cognitive functions and anxiety among blue-collar workers in hospitals during COVID-19 pandemic.

Background: The rapid spread of COVID-19 poses a major threat to public health worldwide. Hospital blue-collar workers, like other health care workers, may be under severe physical and psychological stress. This psychological distress is mainly described as symptoms of anxiety and depression, stress and cognitive function. This study aimed to investigate the effects of anxiety on cognitive function among laundry and sterilization center workers in 4 hospitals during COVID-19 pandemic. Method: This study has a cross-sectional design and it was conducted among health service workers who were occupied in health facilities (laundry and sterilization center) in 4 hospitals. In the present study, two questionnaires and a test were used to collect the data included a general health questionnaire (GHQ-28), a health anxiety index questionnaire (HAI-18) and a cognitive function test. Descriptive statistics and Spearman correlation coefficient by SPSS version 19 were used. Results: The results showed that the overall score of coronavirus anxiety in male and female workers was 38.72 ± 5.94 and 40.92 ± 4.11, respectively. The correlation between auditory attention and coronavirus anxiety is moderate and has a negative trend (P = 0.050, n = 50, and r = -0.315). Workers with higher anxiety expressed lower auditory attention. Also, correlation between visual attention and coronavirus anxiety was weak and negative (P = 0.032, n = 50, and r = -0.179). Conclusion: This study revealed that cognitive and psychological aspects of mental health can be affected by COVID-19 exposure and its due anxiety in blue-collar workers in hospitals. These findings indicate that purposeful supportive interventions should be implemented to promote workers' health and cognitive function.

Application of a TiO2 nanocomposite in earplugs: a case study of noise reduction.

Background. Use of hearing protection devices has become necessary when other control measures cannot reduce noise to a safe and standard level. In most countries, more effective hearing protection devices are in demand. Objective. The aim of this study was to examine the effects of titanium dioxide (TiO2) nanoparticles on noise reduction efficiency in a polyvinyl chloride (PVC) earplug. Methods. An S-60 type PVC polymer as the main matrix and TiO2 of 30-nm size were used. The PVC/TiO2 nanocomposite was mixed at a temperature of 160 °C and 40 rpm and the samples were prepared with 0, 0.2 and 0.5 wt% of TiO2 nanoparticle concentrations. Results. Earplug samples with PVC/TiO2 (0.2, 0.5 wt%) nanoparticles, when compared with raw earplugs, showed almost equal noise attenuation at low frequencies (500-125 Hz). However, at high frequencies (2-8 kHz), the power of noise reduction for earplugs containing TiO2 nanoparticles was significantly increased. Conclusions. The results of the present study showed that samples containing nanoparticles of TiO2 had more noticeable noise reduction abilities at higher frequencies in comparison with samples without the nanoparticles.

Heat stress and physical capacity: a case study of semi-professional footballers.

BACKGROUND: The aim of this study was to determine heat stress effect on physical capacity of semi-professional footballers in Iran by means of oxygen consumption measurement, heart rate monitoring and WBGT assessment environmental conditions. METHODS: This study compared two different thermal environmental conditions related to sub-maximal exercise and its effect on human physical capacity. Thirty two male footballers (age 25.9 ± 1.4 year; height 176 ± 2.9 cm and weight 71 ± 9.8 kg) were investigated under four workloads (50,100,150 & 200 W) in two different thermal conditions in the morning (WBGT=21 °C) and afternoon (WBGT=33 °C) in summer. Each test cycle lasted for 10 minutes with a 10 min interval for recovery and rest between every workload. In the end of each stage, the heart rate, blood pressure, skin temperature and oral temperature were measured and recorded. Expired air was collected and its volume was measured using standard Douglas bags. The WBGT index was also used to monitor the stressful heat condition. RESULTS: Heart rate and VO2 consumption findings for different workload showed a significant difference between morning and afternoon (P<0.001). HR and VO2 consumption in both morning and afternoon courses showed a liner relation (r=0.88, r=0.9 respectively). CONCLUSION: With increasing work load beside heat stress, heart rate and oxygen consumption increased. It is recommended that with Ta>35 °C or WBGT>28 °C, physical activates and performing exercises should be avoided in order to reduce the risk of heat stress-related conditions in athletes.