Concurrent Lead and Noise Exposure Effects on Testicular Tissue of Rat: An Experimental Study.

Objective: Environmental stressors such as physical and chemical factors can have a destructive testicular function. The present study aimed to determine the effect of concomitant exposure to lead and noise on testicular tissue in male rats. Materials and methods : Twenty male Wistar rats (250-300 g, 12-13wk) were divided into four groups (n=5/each): 1) Control group, 2) Lead group treated with 4 mg/kg lead acetate by gavage for 30 days, 3) Noise group exposed to 4 kHz octave band at 105 dBA for eight hrs./ day for 30 days, and 4) the exposed group to lead plus noise concurrently. The testes' weight was measured, and testes abnormalities were assessed after staining with Hematoxylin and Eosin. Results: The results showed that the weight of testes in experimental groups was significantly decreased compared with the control group (p<0.0001). Also indicated edema, degeneration and necrotic cell debris in the lumen, congestion and atrophy of seminiferous tubule in rat testes tissue due to sub-acute exposure to lead and noise. Conclusion: Exposure to 105 dB and lead can cause damage to the seminiferous tubules, intubation edema, and testicular weight loss compared to control. We also found that simultaneous exposure to noise and lead could have more detrimental effects on testicular histology and weight than others.

Relationship between risk perception toward hearing conservation and using hearing protection devices among offset printing workers in Tehran province, Iran.

The way workers perceive noise exposure can play an important role in the adoption of safety behaviors. Therefore, the determination of the relationship among risk awareness, behavior, and exposure can be an extremely important issue in controlling noise exposure. The aim of this study was to investigate the association between risk perception and practice of workers. Workers from 16 printing houses in Tehran province participated in present study. A questionnaire was used for determining the level of risk perception and practice about hearing conservation. The results revealed a significant relationship between risk perception and safety behavior adoption (P < 0.001). A positive and significant correlation was found between these two variables (P < 0.001; rs = 0.912). Also, the results showed that workers with hearing impairment had a better practice. In addition, attention should be paid to preventive principles and encouragement of hearing protection devices usage among employees.

The effect of listening to Iranian pop and classical music, on mental and physiological drowsiness.

Driver's drowsiness is one of the high-risk road behaviors that quadruples the risk of road accidents. Measures to deal with drowsiness during driving include listening to music. The present study investigates the effect of two types of music, namely Iranian high-tempo pop and classical music, on mental and physiological drowsiness during driving. Twelve male students at Tehran University of Medical Sciences within the normal range of the Epworth Drowsiness Scale (ESS) participated in this study. Two types of music (classical and pop) were assessed on two separate days with an interval of one week. The mental aspect of drowsiness was evaluated using the Karolinska Sleepiness Scale (KSS), the physiological aspect by monitoring the EEG and heart rate, and the functional aspect through the mean and standard deviation of speed and the Standard Deviation of Lateral Position (SDLP) in a driving simulator. The results showed that the brain waves (four algorithms (1) (θ + α)/ß, (2) α/ß, (3) (θ + α)/(α + ß) and (4) θ/ß), the KSS score, SDLP and standard deviation of speed all decrease while the mean heart rate increases when listening to music during driving compared to driving without music. No significant difference was observed in the mean speed when exposed to music. Moreover, no difference was observed between the effect of the two music styles, i.e. Iranian classical and pop music. Listening to Iranian classical and pop music while driving improves the driver's performance and reduces drowsiness. The present study showed that higher tempo music during driving can reduce drowsiness and change physiological responses and driving performance.

Influences of Occupational Burnout and Personality on Lipid Peroxidation Among Nurses in Shahroud City, Iran.

Considering the relationship between occupational burnout and oxidative stress, identifying the factors that affect occupational burnout, such as recognizing individual characteristics, would be beneficial for implementing strategies to reduce oxidative stress levels. This study was conducted on 92 nurses from a hospital in Shahroud, a city in northeastern Iran, who were chosen at random. The data was collected through the Demographic Questionnaire, Maslach Burnout Inventory and Personality Factors Inventory. Each participant's serum markers of oxidative stress were also measured. Total antioxidant capacity (TAC) and neuroticism were found to have a negative relationship in this study. Furthermore, marital status, the ward where nurses work, the type of contract, emotional exhaustion, and depersonalization were all found to be significant predictors of malondialdehyde (MDA). Neuroticism, emotional exhaustion, and depersonalization were the most important predictors of oxidative stress levels.The results of this study suggest that some approaches to reducing oxidative stress can be implemented by identifying the factors influencing occupational burnout and also by recognizing individuals' personality traits.

The Effect of Mobile Radiation on the Oxidative Stress Biomarkers in Pregnant Mice.

Objective: Due to the growing use of communication instruments such as cell phones and wireless devices, there is growing public concern about possible harmful effects, especially in sensitive groups such as pregnant women. This study aimed to investigate the oxidative stress induced by exposure to 900 MHz mobile phone radiation and the effect of vitamin C intake on reducing possible changes in pregnant mice. Materials and methods: Twenty-one pregnant mice were divided into three groups (control, mobile radiation-exposed, and mobile radiation plus with vitamin C intake co-exposed (200 mg /kg)). The mice in exposure groups were exposed to 900 MHz, 2 watts, and a power density of 0.045 µw /cm2 mobile radiation for eight hours/day for ten consecutive days. After five days of rest, MDA (Malondialdehyde), 8-OHdG (8-hydroxy-2' -deoxyguanosine), and TAC (Total Antioxidant Capacity) levels were measured in the blood of animals. The results were analyzed by SPSS.22.0 software. Results: The results showed that exposure to mobile radiation increased MDA (P=0.002), and 8-OHdG (P=0.001) significantly and decreased Total Antioxidant Capacity in the exposed groups (P=0.001). Taking vitamin C inhibited the significant increase in MDA and 8-OHdG levels in exposed groups. Conclusion: Although exposure to mobile radiation can cause oxidative stress in the blood of pregnant mice, vitamin C as an antioxidant can prevent it.

The relationship between emotional intelligence, personality traits and safety behaviors in metal industries workers: Confirmatory factor analysis.

BACKGROUND: Human errors cause accidents in the workplace. Screening workers at employment can prevent future accidents from happening. Two important tools that can be helpful in screening are determining the emotional intelligence score and personality traits score of the workers. OBJECTIVE: The purpose of this study was to evaluate the relationship between emotional intelligence, personality traits and safety behaviors in metal industries workers. METHODS: This is a cross-sectional survey. Confirmatory factor analysis was performed to determine the relationship between the components of emotional intelligence, unsafe behaviors, and personality. To collect data for this study, Five-Factor Goldberg questionnaire, Bar-On Emotional questionnaire and Safety behavior questionnaire were used. The collected data were entered into software (SPSS version 22) and refined. RESULTS: The results of this study showed that there was a significant positive correlation between personality traits, emotional intelligence and safe behaviors (p-value = 0.000). The confirmatory factor analysis showed that personality traits influence safe behaviours. Also, studies have shown that emotional intelligence has a positive effect on safe behaviours. The amount indicators of goodness of fit (GFI), Comparative Fit index (CFI), Tucker-Lewis index (TLI) and root mean square error approximation (RMSEA) were 0.944, 0.970, 0.965 and 0.061, respectively. CONCLUSIONS: The results of this study suggest that personality traits and emotional intelligence influence safe behaviours in the workplace. Employers can use these two tools in the employment phase and prevent future human-related accidents.

The effect of occupational noise exposure on systolic blood pressure, diastolic blood pressure and salivary cortisol level among automotive assembly workers.

Introduction. Both auditory and non-auditory health can be affected by exposure to occupational noise. The aim of this study was to evaluate the association of high occupational noise (at three levels) with systolic blood pressure (SBP), diastolic blood pressure (DBP) and salivary cortisol concentration in an automotive factory. Methods. This study was carried out on 78 male workers from a factory who worked in the warehouse unit (control group: 60-70 dB(A)) and assembly units (two test groups: 75-85 and 85-95 dB(A)). Data were collected through questionnaires and measurement of SBP, DBP, saliva cortisol concentration and body mass index (BMI), prior to and post occupational noise exposure. The measurements were performed twice/day and repeated after 10 days. Results. For each occupational noise level group, there was no significant association between cortisol level with age and BMI. The SBP and DBP in all groups increased significantly. Also, the average cortisol levels were similar in different groups before noise exposure, but were statistically different after occupational noise exposure. Conclusions. High occupational noise exposure increases the cortisol level and blood pressure, which are the major risk factors of cardiovascular disease.

Identification, Selection and Prioritization of Key Performance Indicators for the Improvement of Occupational Health (Case Study: An Automotive Company).

Regarding the important role of occupational health in the continuous improvement of organizations, the aim of this study was to identify, select and prioritize key indicators for improvement of occupational health in an automotive company. This cross-sectional descriptive study was carried out in three stages. First, a semi-structured interview as well as an inspection and a review of the company's documentation and studies were carried out, and a set of key indicators were identified and selected. Then, the validity of the indicators were determined by experts (N = 11). Following that, the indicators were prioritized based on SMART criteria. Following the study framework, we collected a set of indicators that included 45 health indicators and 17 educational ones. The results of examining their content validity showed that among the 45 primary health indicators and 17 educational ones, 12 and 9 indicators had acceptable validity, respectively, and a total of 21 indicators were suggested for the purpose of the study by the expert team. The results of prioritizing showed that the leading indicator such as the percentage of corrective and preventive health actions done with the weight of 0.146 was the first priority. A set of key indicators was proposed according to the results, based on the objective of the study, which can help managers and industrial hygiene experts to assess performance in the automotive industry.

Relationship between Noise Annoyance and High Blood Pressure in Workers Exposed to Chronic Noise Among the Workers of an Automotive Industry.

BACKGROUND: Chronic exposure to noise in workplaces is one of the most important physical agents that affects workers' health and causes social and individual problems. The aim of this study was to investigate the relationship between noise annoyance and blood pressure (BP) of workers of an automotive industry. METHODS: In this cross-sectional study, 250 workers were randomly selected. The subjects were classified in two groups based on the exposure to sound pressure levels lower and higher than 85 dB (106 and 144 workers, respectively). In this study, BP was measured using an ALPK2 mercury pressure gauge. To measure annoyance levels, an annoyance questionnaire containing a numerical question numbered 0-11 was used. RESULTS: The mean age of the subjects was 36.19 (±3.75) years. The results showed that the systolic (SBP) and diastolic blood pressure (DBP) of the subjects exposed to the sound pressure levels higher than 85 dB were significantly higher than those exposed to a sound pressure level lower than 85 dB (P < 0.01). Also, the results of the multivariate regression showed a significant relationship between the annoyance and DBP and SBP caused by chronic exposure to noise and sound pressure levels (P < 0.01). CONCLUSION: The results of this study showed that the annoyance caused by exposure to chronic noise in the workplace causes stress in the workers and, in the long term, could increase the risk of high SBP and DBP.

Relationship Between Noise Annoyance and Cognitive Performance in Automotive Workers Exposed to Chronic Noise.

Among the most important complaints of people exposed to noise are the feelings of resentment and annoyance, and the changes in mental conditions, which are among the main psychological consequences affecting the concentration and accuracy of workers. This study was designed to investigate the relationship between annoyance and cognitive performance of workers exposed to chronic noise. This is a descriptive-analytical study conducted on workers in an automotive company. Three hundred workers exposed to noise were entered into the study in two groups: administrative (150 people) and industrial (150 people). The Tower of London and the Stroop computerized psychological tests were used to determine the cognitive status of the workers, and a questionnaire with numbered questions (numbered 1 to 11) was used in order to determine their level of annoyance. There was a significant correlation between the workers' cognitive performance and annoyance levels (P value <0.001). Linear regression results showed that cognitive performance had a significant relationship with the received sound intensity, while the workers' annoyance had a significant relationship with cognitive performance only in the number of wrong answers, the number of unanswered questions, and the number of correct answers in the Stroop test (P value <0.001). The researchers concluded that exposure to chronic noise in work environments could bring about occupational annoyance, and consequently, cognitive disorders, which could increase the risk of errors. More studies are needed to further explore this relationship.

Combined Effect of Noise and Smoking on the Cognitive Performance of Automotive Industry Workers.

INTRODUCTION: Noise is an environmental stressor and can cause or exacerbate mental disorders, and affect the individual performance in certain conditions. This study aimed to evaluate the combined effects of noise and smoking on the cognitive performance of the workers in the automotive industry. METHODS: This research is a descriptive-analytical study with a cross-sectional design conducted on 300 workers randomly assigned into two groups of noise-exposed and nonexposed. They were examined using computerized tests, including the Tower of London test (TOL), Continuous Performance test (CPT), and Stroop test. The sound pressure levels were measured based on an 8-hour equal-loudness contour in each group according to ISO 9612 standard, using the Testo CEL-815 sound level meter. RESULTS: The study of combined effects of noise and smoking on 12 CPT indicators using the 2-way Analysis of Variance (ANOVA) indicate that noise and smoking factors had a significant impact on the mean number of errors and correct responses in the third 50-stimuli stage, the mean number of errors and correct responses in the second 50-stimuli stage with P<0.001, P<0.001, P=0.012 and P<0.001 for smoking respectively, but only noise affected the other 7 indicators (P<0.001). CONCLUSION: Smoking and noise have negative impacts on concentration, attention, and cognitive processing speed, which can lead to an individual's mistakes and delayed decision making at the workplace.

Effect of Chronic Noise Exposure on Aggressive Behavior of Automotive Industry Workers.

BACKGROUND: Noise pollution is one of the important harmful physical factors in work environment in developed and developing countries. It not only causes a variety of physiological effects, but also accounts for psychological disorders. OBJECTIVE: To investigate the effects of chronic exposure to noise on aggression in automotive industry workers. METHODS: In a cross-sectional study conducted in an Iranian automotive industry, a group of workers were randomly selected from different parts of the paint shop. The workers' aggression level was measured using the Buss and Perry's questionnaire. The noise level was also measured at the workplace. Using linear regression analysis, the relationship between the level of aggression and noise level was evaluated. RESULTS: 250 workers with a mean age of 36.1 (SD 3.7) years were studied. There was a significant (p<0.05) correlation between the measured noise intensity and the aggression level of the studied workers. CONCLUSION: Exposure to noise in work environment increases the incidence of tension and inappropriate behavior associated with aggression. Controlling noise through use of protective equipment might reduce the deleterious effects of noise on workers.

The effects of radiofrequency radiation on mice fetus weight, length and tissues.

The public concern of harmful effects of radiofrequency radiation exposure, especially with rapid increase in the use of wireless and telecommunication devices, is increasing. Some studies show fetal and developmental abnormalities as the result of radiofrequency radiation exposure. We aimed to investigate possible teratogenic effects of radiofrequency in 915 MHz on mice fetus and protective role of vitamin C. 21 pregnant mice were divided into 3 groups. Control group was in normal condition without any stressor agent. Exposure group was exposed to 915 MHz RFR (8 h/day for 10 days) and 0.045 µw/cm2 power density. The exposure plus vitamin C group received 200 mg/kg vitamin C by gavage and was exposed to 915 MHz RFR (8 h/day for 10 days) and 0.045 µw/cm2 power density. The fetus weight, C-R length were measured by digital balance and caliper. Tissues were assessed after staining with H & E. Our results showed significant increase in fetus weight and C-R length and also enlarged liver, tail deformation in mice fetus in exposure group. Although usage of vitamin C caused significant decrease in mentioned parameters. The outcome of this study confirms the effects of radiofrequency radiation on growth parameters such as body weight, length and some tissues in mice fetuses and protective effect of vitamin C. However more studies on non-ionization radiation in different frequencies and severity, during pregnancy are needed to clarify the exact mechanisms of these changes and better protection.

A prospective study of psychomotor performance of driving among two kinds of shift work in Iran.

BACKGROUND AND AIM: Driving after a night shift imposes a risk on health care professionals and other road users. The aim of this study was to measure psychomotor performance of driving of night shift nurses compared to day-shift nurses. METHODS: Forty-seven volunteer female nurses working at Sina hospital in Tehran, Iran, with a call in all departments of hospital, participated in this study (23 night shift and 24 day shift nurses) in 2016. The tests included RT for simple reaction time, ATAVT for perceptual speed, LVT for visual orientation and ZBA for time anticipation. Data collection tools were individual characteristics, 11-item circadian type inventory (CTI), Stanford sleepiness scale (SSS), and Swedish occupational fatigue inventory (SOFI-20) questionnaires. Psychomotor driving performance was assessed using validated computerized traffic psychological battery of Vienna Test System (VTS), before and after the shifts. Data analysis was performed using paired-samples t-test and Linear Regression. RESULTS: The mean age of day and night-shift nurses were 31.4±5.6 and 28.7±3.9 years respectively, no significant difference between two groups. Thirty percent of night shift and 16.7% of day shift nurses reported traffic accidents in the past year. The results revealed that, scores based on viewing times in visual orientation test (p=0.005), and median reaction time score in choice reaction time and reactive stress tolerance test (p=0.045), had a significant association with a 12-hour night shift with a 3-hour nap. CONCLUSIONS: Twelve-hour night shift work impairs choice reaction time and visual orientation in nurses, even though they take a 3- hour nap during the shift. These skills are required for safe driving.

Chlorobenzene degeradation by non-thermal plasma combined with EG-TiO2/ZnO as a photocatalyst: Effect of photocatalyst on CO2 selectivity and byproducts reduction.

The non-thermal plasma (NTP) technique, which suffers from low selectivity in complete oxidation of volatile organic compounds to CO2 and H2O, creates unwanted and harmful byproducts. NTP in concert with photocatalyst can resolve this limitation due to additional oxidation. TiO2 and ZnO nanoparticles were coated on the surface of the expanded graphite and placed downstream of the NTP reactor under UV light. In this study, to compare the performance of NTP and the combined system, chlorobenzene removal, selectivity of CO2 and byproducts formation were investigated. The results showed that the combined system enhanced both the removal efficiency and CO2 selectivity. The output gas of the NTP reactor contained chlorobenzene, phosgene, O3, NO, NO2, CO, CO2, HCL and CL. The bulk of these byproducts was oxidized on the surface of the nanocomposite; as a result, the content of the byproducts in the output gas of the combined system decreased dramatically. The removal efficiency and CO2 selectivity increased by rising the applied voltage and residence time because the collision between active species and pollutant molecules increases. Based on these results, the combined system is preferred due to a higher performance and lower formation of harmful byproducts.

The Effect of Occupational Noise Exposure on Blood and Biochemical Parameters: A Case Study of an Insulator Manufacturer in Iran.

INTRODUCTION: Occupational noise is among the most critical occupational hazards, which, in addition to hearing loss, can cause other adverse consequences on an individual's physical and mental health. Long-term exposure to noise can affect blood and biochemical parameters and subsequently lead to increased risk of cardiovascular disease. This study investigated the effect of occupational exposure to noise on blood and biochemical parameters of workers in an insulator manufacturing plant. METHODS: This case-control study was conducted on workers in the production section (49 people as a case group) and the administrative staff (10 people as a control group) in one insulator manufacturing plant from 2010 to 2014. To assess individual exposure of workers to noise, the noise dosimeter model TES-1355 was used. Noise dosimetry testing was done based on the exposure pattern of workers to noise in compliance with the Iranian national standard (the criterion level of 85 dBA and the exchange rate of Q = 3 dBA). Blood parameters such as blood glucose, cholesterol, red blood cells (RBC), white blood cells (WBC), hemoglobin (Hb), and hematocrit (Hct) were studied in production workers (case) and administrative staff (control) over five consecutive years. The data were analyzed by software (SPSS-22) using the t-test, Mann-Whitney test, Fisher exact test, and Greenhouse-Geisser test. RESULTS: No significant difference was found among the demographic data of the two groups (p > 0.05). Average of glucose and cholesterol levels in the two groups was statistically significant (p < 0.05) and blood glucose levels in the case group significantly reduced over time and cholesterol increased (p < 0.001). Mean difference of RBC number, WBC number, and serum levels of Hb and Hct was statistically significant between the two groups (p < 0.05). In addition, these hematological parameters increased among workers during these years. CONCLUSION: Occupational exposure to noise may have a significant effect on an individual's blood parameters, which will cause harmful effects on worker health. Therefore, industrialists must take preventive measures in the field of noise control.

The Effect of Road Traffic Noise on Reaction Time.

BACKGROUND: Traffic noise is one of the main important sources in urban noise pollution, which causes various physiological and psychological effects that can cause disturbs in performance, sleep disturbances, hearing loss and impact on job performance. This study was conducted to verify the impact of road traffic noise on reaction time in terms of extraversion and sex. METHODS: Traffic noise was measured and recorded in 10 arterial streets in Tehran, and then the recorded noise was emitted towards participants in an acoustic room. The participants were 80 (40 cases and 40 controls) students. Personality type was determined by Eysenck Personality Inventory (EPI) questioner. Reaction time before and after exposure to traffic noise was measured. RESULTS: Reaction time before exposure to traffic noise did not differ (P=0.437) significantly between introverts and extraverts. However, it was increased significantly in both groups after exposure to traffic noise (P<0.01). Introvert's reaction time was more increased than that of extraverts. CONCLUSION: Traffic noise augmented reaction time of both males and females. This study also revealed that exposure to traffic noise leads to increase in reaction time.

Reliability and validity of a safety climate questionnaire.

BACKGROUND: It is believed that improved safety culture/climate is a fundamental element to accident prevention. Therefore, development a scale to assess safety climate is a step towards accident control. The purpose of this study was to construct a Persian safety climate questionnaire. METHODS: The study took place in Tehran and Esfahan oil refineries in Iran in 2010. An initial questionnaire was formed from two previous studies. This tool was translated to Persian based on back translation. The 61-item questionnaire was tested on operational staffs (N=324). Principle component analysis and Varimax with Kaiser Normalization was used to extract factors, in statistical software package SPSS 11.0. RESULTS: The factors were obtained as Management Commitment to Safety and personnel collaboration 23 variables, 17.33 % of the variance, Safety communication five items, 6.97% of the variance, Supportive environment five items, 6.245% of the variance, Work Environment six items, 5.590% of the variance, Formal Training four items, 4.581% of the variance, Priority of Safety five items, 4.177% of the variance, Personal Priorities and Need for Safety three items, 3.333% of the variance. CONCLUSIONS: Achievement of a valid and reliable safety climate tool may bring enormous benefits to the refineries. However, a reliable and valid tool to measure safety climate could be useful in other refineries. Moreover, the generic nature of the safety climate scale may grant its use for other workplaces.

The effects of road traffic noise on mental performance.

BACKGROUND: Noise is one of the more widespread pollutions of road transportation system, which can cause deterioration in performance. This experimental study was designed to assess the effect of road traffic noise on performance with regard to extra/introversion and sex of participants. The personality trait of extra/introversion has been remarked as relevant factor to mental performance. RESULTS: Thirty six (26 males and 10 females) medical sciences students of Tehran University participated in the study. The students were placed in an unechoing room and performed the Cognitrone test from Vienna Test System in quiet condition and under road traffic noise (71 dBA). The results of this study pointed out that noise increased the percentage of sum of correct answers but had no effect on the speed of performance. Furthermore this study showed that performance was enhanced in extroverts (P=0.001) but no significant difference was found in introverts (P ≤0.05). CONCLUSIONS: The regression analysis revealed that extra/introversion was more important than sex to predict the performance parameters.

The effects of low frequency noise on mental performance and annoyance.

Low frequency noise (LFN) as background noise in urban and work environments is emitted from many artificial sources such as road vehicles, aircraft, and air movement machinery including wind turbines, compressors, and ventilation or air conditioning units. In addition to objective effects, LFN could also cause noise annoyance and influence mental performance; however, there are no homogenous findings regarding this issue. The purpose of this research was to study the effects of LFN on mental performance and annoyance, as well as to consider the role of extraversion and neuroticism on the issue. This study was conducted on 90 students of Iran University of Medical Sciences (54 males and 36 females). The mean age of the students was 23.46 years (SD = 1.97). Personality traits and noise annoyance were measured by using Eysenck Personality Inventory and a 12-scale self-reported questionnaire, respectively. Stroop and Cognitrone computerized tests measured mental performance of participants each exposed to 50 and 70 dBA of LFN and silence. LFNs were produced by Cool Edit Pro 2.1 software. There was no significant difference between mental performance parameters under 50 and 70 dBA of LFN, whereas there were significant differences between most mental performance parameters in quiet and under LFN (50 and 70 dBA). This research showed that LFN, compared to silence, increased the accuracy and the test performance speed (p < 0.01). There was no association between LFN and noise annoyance (p > 0.01). Introverts conducted the tests faster than extraverts (p < 0.05). This research showed that neuroticism does not influence mental performance. It seems that LFN has increased arousal level of participants, and extraversion has a considerable impact on mental performance.