Assessment of semen quality of taxi drivers exposed to whole body vibration.

Whole body vibration (WBV) is a recognized occupational hazard for many workers such as drivers and operators of heavy and light machinery and exposure to it is accompanied by physical and mental repercussions. Only the limited studies have been done on the effects of vibration exposure on reproductive indices, however vibration exposure has been indicated as being a hazardous agents with the potential of being able to directly affect the reproductive system. Considering the importance of infertility, the present study was conducted with the aim of investigating semen quality among taxi drivers in Tehran and determine the effect of exposure to WBV on sperm parameters. The study population consisted of 70 taxi drivers and 70 office employee who attended infertility clinics for diagnostic purposes in the past year. The participants had to meet the entry criteria of the study while also being willing to recruit. Data was collected in the form of demographic questionnaires and general health questionnaires as well as sperm analysis conducted in an infertility clinic according to standard laboratory guidelines. The 8-hour time-weighted average (TWA) exposure to of WBV in automobile was measured as per ISO 2631-1. The TWA exposure to WBV among the taxi drivers and office employees were 0.697 ± 0.13 m/s2 and 0.068 ± 0.09 m/s2 respectively (P < 0.05). A statistically significant difference in total sperm count, progressive motility, non-progressive motility and total motility was observed between the taxi drivers and the office employees (P < 0.05). According to the univariate analysis of variance, exposure to WBV had negative effect on sperm concentration, progressive motility and normal morphology (P > 0.05); moreover exposure to WBV resulted in the larger effect size (B) on sperm parameters than the demographic variables (P > 0.05). Being taxi drivers increase the chance of the decreased semen quality (P > 0.05). It is difficult to draw definitive conclusions regarding the effects of WBV while intervening factors exist, such as psychological stressors, quality of sleep, background issues as well as environmental factors such as chemical pollutants (heavy metals) or ergonomic factors (body posture and working while sitting down).

Development and validation of assessment tool of knowledge, attitude, and practice of outdoor workers regarding heat stress.

BACKGROUND: Improving the level of knowledge, attitude and practices of workers exposed to heat stress using a suitable tool can be a cheap and effective method. This requires the consideration of personal, environmental and social factors, which, the PRECEDE model is highly applicable for. Thus, the aim of the present study is the development of a tool assessment for measuring the knowledge, attitude and practices of workers in outdoor occupations regarding heat stress exposure using the PRECEDE model. METHODS: In the present study, a tool was designed and constructed using the PRECEDE model by analyzing the relevant literature and expert opinion. The face validity of the tool was determined based on the opinion of ten experts with experience in the field of occupational weather conditions. The content validity of the tool was determined using the Content Validity Ratio (CVR) and the Content Validity Index (CVI). Cronbach's alpha reliability coefficient was used to determine the reliability of the tool's internal consistency. SPSS version 23 was used for statistical analysis. RESULTS: A PRECEDE based questionnaire was designed with a total of 55 questions consisting of predisposing factors (28 questions for knowledge and 14 questions for attitude), enabling factors (5 questions), reinforcing factors (3 questions) and preventive behaviors (5 questions). The Content Validity Index (CVI) of all questions was above 0.79. The Content Validity Ratio (CVR) of all questions was above 0.62 (Lawshe method). The Cronbach's alpha reliability coefficient of all PRECEDE domains were above the 0.7 acceptable value. Based on the results obtained, all 55 questions were approved and thus the content validity and reliability of this tool was deemed acceptable. CONCLUSION: Considering the reliability and validity of this tool, its application is recommended in all health and safety inspections within various industries for measuring the heat stress knowledge, attitude and practices of workers engaged in outdoor occupations and also for presenting suitable solutions or preventive measures.

Relationship between occupational exposure to whole-body vibration and noise with sex hormone levels: An empirical assessment in an automobile parts manufacturing plant.

The present study investigated the relationship between occupational exposure to noise and whole-body vibration (WBV) with the levels of sex hormones in an automobile parts manufacturing plant. The level of workers' exposure (n = 162) to each of the mentioned stressors was measured through standard methods, and the time-weighted average of exposure was calculated for each person. In order to determine serum sex hormones (free testosterone, luteinizing hormone, and follicle-stimulating hormone), blood samples were taken from all participants after 8-10 h of fasting between 7 and 9 am and then the blood samples were analyzed by an enzyme-linked immunosorbent assay method. In general, regarding testosterone as the main male sex hormone, only 49% of the participants were in the normal range. In a total of three sections, the lowest mean testosterone levels were observed in the third exposure group (WBV > 1.93 m/s2; noise >92.69 dB) of the studied stressor; however, only the difference in testosterone levels between the three different groups of exposure to noise was statistically significant (p = 0.001). The relationship between demographic variables and levels of noise and WBV exposure with sex hormones was not linear and only the relationship between noise exposure and testosterone levels was statistically significant (R = -0.201, p = 0.013). According to the results of logistic regression, the WBV had the greatest effect on testosterone levels. However, according to the results of the correlation test, only the relationship between noise exposure and testosterone levels was statistically significant.

Assessment of sexual hormones in foundry workers exposed to heat stress and electromagnetic fields.

The presence of hazardous agents in workplaces has raised concerns regarding their possible impacts on male reproductive system. The present study investigated the individual and combined effects of exposure to heat stress and electromagnetic fields with low-frequency characteristics on the levels of sex hormones in two foundry sections (Aluminum and Cast Iron) of an automobile parts manufacturing plant. The level of workers' exposure (n = 110) to each of the mentioned stressors, was measured through standard methods and for each person and the time-weighted average (TWA) of exposure was calculated. The participants of each sections were classified into separate exposure groups based on the 33rd and 66th percentile of the level of to heat stress and electromagnetic fields exposure. In order to determine serum sex hormones, blood samples were taken from all participants between 7-9 am and then the blood samples were analyzed by ELISA method. In total of two sections, the lowest mean testosterone levels was observed in the third exposure group of the electromagnetic fields (magnetic field>1.40 µT; electric field >0.42 V/m), however, the mean difference in testosterone levels between the three different groups of exposure wasn't statistically significant (P > 0.05). According to the results of Logistic Regression, the electric field had the greatest effect on testosterone levels as the main male hormone. Drawing a definitive conclusion regarding the effects of each harmful physical hazards is difficult due to the existence of psychological stressors and other environmental stressors such as chemical pollution, ergonomic hazards and other physical stressors.

Application of Universal Thermal Climate Index (UTCI) for assessment of occupational heat stress in open-pit mines.

The purpose of this article is to examine the applicability of Universal Thermal Climate Index (UTCI) index as an innovative index for evaluating of occupational heat stress in outdoor environments. 175 workers of 12 open-pit mines in Tehran, Iran were selected for this research study. First, the environmental variables such as air temperature, wet-bulb temperature, globe temperature, relative humidity and air flow rate were measured; then UTCI, wet-bulb globe temperature (WBGT) and heat stress index (HSI) indices were calculated. Simultaneously, physiological parameters including heart rate, oral temperature, tympanic temperature and skin temperature of workers were measured. UTCI and WBGT are positively significantly correlated with all environmental parameters (p<0.03), except for air velocity (r<-0.39; p>0.05). Moreover, a strong significant relationship was found between UTCI and WBGT (r=0.95; p<0.001). The significant positive correlations exist between physiological parameters including oral temperature, tympanic and skin temperatures and heart rate and both the UTCI and WBGT indices (p<0.029). The highest correlation coefficient has been found between the UTCI and physiological parameters. Due to the low humidity and air velocity (~<1 m/s) in understudied mines, UTCI index appears to be appropriate to assess the occupational heat stress in these outdoor workplaces.

Assessment of the effect of welding fumes on welders' cognitive failure and health-related quality of life.

INTRODUCTION: This study examined whether cognitive symptoms and health-related quality of life can be affected by welding fume exposure. METHOD: Participants consisted of welders (n = 40) and welder assistants (n = 25) from welding units as the exposed group, and office workers (n = 44) as the non-exposed group. All participants were studied using ambient air monitoring and two types of questionnaires: the Cognitive Failures Questionnaire (CFQ) and the 36-item Short Form Health Survey (SF-36). RESULTS: Welders and welder assistants were exposed to higher concentrations of all airborne metals than office employees, except for aluminum and chromium (p < 0.05). Mean (95% confidence interval) CFQ score was higher in welders (26.42 (12.74)) compared with welder assistants (22.68 (14.37)) and the non-exposed group (21.38 (8.75)), although these differences were not statistically significant. Mean total score of the SF-36 significantly differed among the three groups (p < 0.05) and welders had the lowest score (M (SD) = 54.84 (17.88)). The relationships between total CFQ score and the measured concentration of nickel at peak work rate was significant for welders. CONCLUSION: Cognitive symptoms and health-related quality of life were not related to the measures of welding fume exposure and further research should be performed to find other influencing factors.

Applicability of Universal Thermal Climate Index (UTCI) in occupational heat stress assessment: a case study in brick industries.

The present study aimed to investigate the applicability of Universal Thermal Climate Index (UTCI) as an innovative and science-based index in public health researches, in occupational heat stress assessment. All indoor and outdoor workers (200 people) of Brick industries of Shahroud, Iran participated in the research. First, the environmental variables such as air temperature, wet-bulb temperature, globe temperature, air velocity and relative humidity were measured; then UTCI and WBGT (wet-bulb globe temperature) indices were calculated. Simultaneously, physiological parameters including systolic and diastolic blood pressure, oral temperature, skin temperature, tympanic temperature and heart rate of workers were measured. UTCI and WBGT indices were 34.2 ± 2°C, 21.8 ± 1.8°C in the outdoor environments and 38.1 ± 4.4°C, 24.7 ± 3.3°C at the indoor environments, respectively. There were the weak inverse relationships between UTCI and WBGT indices at the outdoor environments and physiological responses such as systolic blood pressure, and diastolic blood pressure. However, there were no similar results for indoor environments. The significant relationships were found between UTCI and WBGT at both indoor and outdoor environments. Both UTCI and WBGT indices are suitable for assessing the occupational heat stress. Although, UTCI index seems more appropriate for heat stress assessment in the environments with low humidity and air velocity.

A prioritization approach for noise risk management in a petrochemical complex.

OBJECTIVES: Noise is probably the most common occupational hazard facing workers today. This paper presents a model to evaluate and select a unit as the first priority for implementing noise control measures from the different parts of an industrial complex. METHODS: For this purpose, a formula was proposed as a priority risk index (NCPI) by considering some criteria, including: the number of exposed workers in each part, their exposure times and the range of sound pressure level. The above criteria were weighed by appending weighting factors, which can be different based upon the environmental noise levels. The environmental noise measurements were also carried out by lattice method according to ISO 9612:2009. At the next stage, the numbers of stations that fell within the desired ranges in the weighting factors table were found. then the priorities were identified using the above criteria and the NCPI. RESULTS: The results indicate that the compression unit of air plant had the highest score among the different departments of the company under study (NCPI=0.3). Using this model is easy and fast. It is applicable to similar industries and also offers valuable information for prioritizing noise control measures. CONCLUSIONS: Therefore, it will be possible to minimize worker exposure to noise in the most polluted places in any industry by identifying the main noise sources and implementing measures suitable for controlling the risk.