Effect of personality traits on sensitivity, annoyance and loudness perception of low and high frequency noise

This paper presents investigations into a comparative assessment of the effects of low and high frequency noise in relation to personality traits. The high and low-frequency noises used are produced in the research laboratory using CoolEdit software. 80 candidates are exposed to equivalent continuous sound pressure level of 65 dBA of low and high frequency noise in an acoustic room with a 2 week interval. After 1 hour of exposure to noise, participants were asked to complete noise annoyance scale, Weinstein noise sensitivity questionnaire, loudness perception. The results obtained indicate that there is a significant difference between annoyance and perception of low frequency noise in comparison to annoyance and perception of high frequency noise, but no significant difference is noted between sensitivity to low and high frequency noise. The multivariate analysis of covariance test is applied, which reveals that personality traits have a significant effect on sensitivity to low and high frequency noise, annoyance due to low and high frequency noise, loudness perception of low frequency noise, but no interaction effects are found. It is further shown that personality traits are more effective on sensitivity, annoyance and loudness perception to high frequency noise than those of low frequency noise, and such effects are not only influenced by severity of noise, but also by personality traits and frequency components

Comparison of the Impact of an Optimized Ice Cooling Vest and a Paraffin Cooling Vest on Physiological and Perceptual Strain

Background: Ice cooling vests can cause tissue damage and have no flexibility. Therefore, these two undesirable properties of ice cooling vest were optimized, and the present study was aimed to compare the impact of the optimized ice cooling vest and a commercial paraffin cooling vest on physiological and perceptual strain under controlled conditions. Methods: For optimizing, hydrogel was used to increase the flexibility and a layer of the ethylene vinyl acetate foam was placed into the inside layer of packs to prevent tissue damage. Then, 15 men with an optimized ice cooling vest, with a commercial paraffin cooling vest, and without a cooling vest performed tests including exercise on a treadmill (speed of 2.8 km/hr and slope of %0) under hot (40 ° C) and dry (40 %) condition for 60 min. The physiological strain index and skin temperature were measured every 5 and 15 minutes, respectively. The heat strain score index and perceptual strain index were also assessed every 15 minutes. Results: The mean values of the physiological and perceptual indices differed significantly between exercise with and without cooling vests (P 0.05). Conclusions: The optimized ice cooling vest was as effective as the commercial paraffin cooling vest to control the thermal strain. However, ice has a greater latent heat and less production cost

A Bayesian network based study on determining the relationship between job stress and safety climate factors in occurrence of accidents.

YesJob stress and safety climate have been recognized as two crucial factors that can increase the risk of occupational accidents. This study was performed to determine the relationship between job stress and safety climate factors in the occurrence of accidents using the Bayesian network model. This cross-sectional study was performed on 1530 male workers of Asaluyeh petrochemical company in Iran. The participants were asked to complete the questionnaires, including demographical information and accident history questionnaire, NIOSH generic job stress questionnaire, and Nordic safety climate questionnaire. Also, work experience and the accident history data were inquired from the petrochemical health unit. Finally, the relationships between the variables were investigated using the Bayesian network model. A high job stress condition could decrease the high safety climate from 53 to 37% and increase the accident occurrence from 72 to 94%. Moreover, a low safety climate condition could increase the accident occurrence from 72 to 93%. Also, the concurrent high job stress and low safety climate could raise the accident occurrence from 72 to 93%. Among the associations between the job stress factor and safety climate dimensions, the job stress and worker's safety priority and risk non-acceptance (0.19) had the highest mean influence value. The adverse effect of high job stress conditions on accident occurrence is twofold. It can directly increase the accident occurrence probability and in another way, it can indirectly increase the accident occurrence probability by causing the safety climate to go to a lower level

The relations of job stress dimensions to safety climate and accidents occurrence among the workers

YesBased on a literature review, likely, there is a relationship between job stress and safety climate, and in this way, the accident occurrence is affected. Therefore, the present study was aimed to investigate the relations of job stress dimensions to safety climate and accidents occurrence among the workers using regression models. This cross-sectional study was carried out on 1530 male employees in 2019. People were randomly selected from various departments. The participants filled out the questionnaires, including demographical information and accident history questionnaire, the NIOSH generic job stress questionnaire, and the Nordic safety climate questionnaire. In addition, information on occupational experience and accident history was obtained from the health unit of the petrochemical company. In the end, data were analyzed using statistical tests of bivariate correlation, multivariate correlation, and logistic regression. Based on the bivariate analysis, the variables of job satisfaction (0.998), problem at work (0.900), depression (-0.836), and physical environment (-0.796) among the job stress dimensions had the highest correlation coefficients with the total score of the safety climate, respectively. The results of the logistic regression analysis with the adjustment of the effect of the safety climate indicated that the relationships between the dimensions of the job satisfaction (Wald = 6.50, OR = 4.96, and p-value<0.05) and social supports (Wald = 5.88, OR = 3.20, and p-value<0.05) with the accident occurrence were significant. To increase the positive safety climate and decrease the accident occurrence, industries must try to reduce job stress in the workplaces through controlling the important factors, such as low job satisfaction and poor social supports.This work was supported by Tehran University of Medical Sciences (97-03-61-38355)