Tibbi- i- kar
Year:2016 | Volume:8 | Issue:3|Papers Count:14

Introduction: the rating of perceived exertion (RPE) scale is an index for evaluating personal strain during dynamic activities. This study was carried out to determine the relationship between RPE and heart rate in the people with normal weight and overweight individuals during light and moderate physical activity levels under warm and hot experimental conditions.Methods: This interventional study was conducted on 70 male students and employees (35 individuals with normal weight (BMI<25) and 35 with overweight and obesity (BMI≥25)). Each participant rested for 30 minutes and then performed a 60 minute light activity (2.8 kph on treadmill) with exposure to hot climatic conditions (370C). In the other phase, the participant was asked to rest for 30 minutes and then performed a 60 minute moderate activity (4.8 kph on tread mill) with exposure to warm climatic conditions (320C). The heart rate (by sport tester) and RPE 1-10 scale were recorded every 4 minutes. Finally, SPSS (ver. 16) was used using t-student test and Pearson correlation.Result: There was a significant difference in the mean values of heart rate and RPE between two groups with normal weight and overweight in two climatic conditions (P<0.001). Also The Pearson's correlation coefficient showed that there was a positive relationship between RPE and heart rate in warm (r=0.75, p<0.001) and hot conditions (r=0.52, p<0.001).Conclusion: The mean values of heart rate and RPE were higher in overweight and obese participants than those with normal weight. Also there was a significant correlation between heart rate and RPE but correlation coefficient was lower than other studies in warm and hot condition.

Introduction: Protective clothes are among the basic needs of firefighters against their occupational risks. Combination of heat stress effects caused by muscle activation and protective clothing, result in a high level of strain in the regulating system of body temperature. The aim of this study was to evaluate the practical cooling method of hand and forearm immersion in water. Methods: In this study, fourteen professional firefighters were assessed. Each fire fighter wore protective clothing and heart rate, core body temprature and skin temprature were measured in sitting position. Then each subject walked on a treadmill in two 20-min bouts (5 km/h, 7.5% gradient) separated by a 15-min recovery period, during which firefighters were cooled (case) via application of hand and forearm water immersion and remained seated without cooling (control). During exercise and recovery time, firefighters, physiologic parameters (heart rate, core body temperature and mean skin temperature) were measured and recorded every five minutes.Results: The results of marginally modeling of longitudinal responses using generalized estimating equations method showed that paremeters of heart strain (core body temprature, skin temprature and heart rate) were significantly reduced after intervention (p<0.05).Conclusion: In situations that intense fire actions must be faced, the cooling strategy of dipping hands and forearms in water could be considered as an effective and simple method in comparison to other cooling strategies.

Introduction: Absenteeism is one of the challenging issues in managing human resources. Many social, economic and personal factors may affect sickness absence. We studied effects of some personal factors on sickness absence in a governmental organization.Methods: In a cross-sectional study, we invited all of white collar workers of one governmental organization to participate in this study. Data regarding personal factors collected for volunteers and combined with long-term sickness absence data which extracted from sickness absence certification files.Results: A total of 527 workers, including 408 males and 119 females participated in our study. Of these 527 participants, 70 (13.3%) had a history of long-term sickness absence in the past three years. Sickness absence spells were significantly associated with female sex, smoking, less than three person kinship responsibility, chronic disease and poor self-rated general health, in regression analysis. Working days lost due to sickness absence were significantly associated with female sex, smoking and chronic disease, in regression analysis.Conclusion: Diseases are not the sole cause of sickness absence and other personal factors may play a significant role on making a decision to withdraw from the workplace.

Introduction: Musculoskeletal disorders are predominant causes of workers, disabilities and reducing productivity in industrial countries. Studies should one of the jobs that may cause musculoskeletal disorders, is welding. To investigate the causes of these disorders, this study attempts to find relationships between workplace ergonomics, human anthropometry and the amount of force and torque acting on the lumbar vertebrae of welders.Methods: In this study, two modeling and analysis methods in CATIA V5R20 software and reverse dynamic calculations, were used to assess biomechanical characteristics of 10 manikins with different anthropometric dimensions in 2 different welding positions. Also by using of occupational health and safety standards in software, the motor position of manikins limbs were judged.Results: Inverse dynamics calculations and CATIA software showed that by increasing the stature of American workers about 13%, the torque and force acting on the L4-L5 vertebrae increase approximately 45-47%. Also, by increasing the length of the upper and lower body segments, the percentage of workers who are not capable of welding, increased. In addition, Comparison between sitting and standing welding showed in sitting welding position, the force acting on the vertebrae is 26-28% more than standing position.Conclusion: The results of this study compared with international standards such as NIOSH, indicate that by increasing the length of the upper and lower body segments in welders, the force and torque acting on the lumbar vertebrae increased and because of more force and torque in sitting than standing welding position, perils threaten the low-lying levels welders.

Introduction: In recent years, use of compact fluorescent lamps has increased in order to optimize energy consumption. The aim of this study was to evaluate the radiations of electromagnetic spectrum from usual compact fluorescent lamps.Methods: In this study, 48 compact fluorescent lamps from different brands and cover (warm – cool) were selected. For studied lamps, operational factors consisted of: UVA, UVB illuminannce, intensities of electromagnetic field in very low frequency (VLF) and extremely low frequency (ELF) ranges were measured using calibrated devices.Results: The results showed that intensities of electromagnetic fields and UVA were below the exposure limits, but UVB was above the exposure limits. UVA lamps based on different light color (cover) had significant difference (P=0.008), UVA radiation between companies had significant difference. (P<0.001). Difference between the intensities of electromagnetic fields based on manufacturer was significant (p<0.05).Conclusion: According to the study, compact fluorescent lamps had different amounts of UVA, UVB and electromagnetic fields, and UVB was above the exposure limits. Therefore, it is recommended not to use these lamps as the local electric lightings source without shield at distances of less than one meter. Observing the safety notes against the radiation of electromagnetic spectrum, increasing the distance from the source ,and training seems necessary.

Introduction: In many industrial and mining environments, heat stress not only leads to a lower productivity and poor morale, but also it increases the cost of accidents. Heat stress indices have been developed to assess heat stress at workplace. The objective of this study was to evaluate heat stress and to investigate the correlation between ESI index and some physiological parameters of workers in an open pit mine.Methods: This cross-sectional study was conducted on 120 healthy miners. Tympanic and skin temperatures were measured using a FT70 model thermometer manufactured by Beurer Co, Germany. Heart rate and blood pressure were measured using Emsig BO26 model (Taiwan) digital instrument. All environmental and physiological parameters were simultaneously measured and recorded during rest and work. The ESI index was calculated using the formula. Finally, the correlations were determined using Pearson's correlation test.Results: The average ESI index calculated for individuals was 29.23oC. Drilling and transportation units had the highest and lowest ESI values of 30.45oC and 28.03oC, respectively. The statistically significant correlation was found between ESI heat stress Index and physiological parameters (p<0.01). The Pearson's correlation coefficient of ESI with tympanic temperature, skin temperature, heart rate, systolic and diastolic blood pressure was 0.614, 0.507, 0.482, 0.355 and 0.247, respectively. The highest correlation of 0.614 was related to the tympanic temperature.Conclusion: Heat stress at the studied open pit mine was high. Drilling workers were faced to higher thermal stress and ESI had an acceptable correlation with physiological parameters. Further studies on ESI at different working environments are recommended.

Introduction: Noise is one of the most important physical agents in the workplace which causes numerous effects on physical and mental health. Hence its elimination or control is necessary in noisy industrial workplaces. Saab dyamples device is one of the most important sources of noise in the sub line in granite industry. Thus, this study intended to reduce noise using enclosure method in Behsaram granite company. Methods: Due to the high level of noise produced by dyamples, in this study, the enclosure technique was used to encapsulate the noise area. After measurement and analysis, the required noise reduction was determined. A chamber with dimensions of 1.5×1.55×1.8 m3 with an opening in front for observation and another opening in the back for access to control keys. The chamber was manufactured from galvanized stainless steel with 0.55 thickness and 6 kg/m2 density with a glass wool cover with 2 inches thickness.Results: The noise level before and after enclosure was 93.63 dB and 86.91 dB, respectively. According to the measured values before and after the installation of the chamber.Conclusion: Considering noise reduction, it is recommended that engineering controls (enclosure) in similar industries could reduce exposure of the workers to high level of noise.

Introduction: Due to the large numbers of staff employed in health care services, the hospital should be seen as a big industry, with many workers mostly females. This fact along with the lack of sufficient manpower, and also frequent handling and transport of load (patient) in hospitals causes an increase of musculoskeletal disorders among personnel, so that most of the hospital personnel in the first few years, of employment suffer from Musculoskeletal disorders.Methods: The study was designed and implemented in four parts of the Nahavand Alimoradiyan hospital with aim of reducing musculoskeletal disorders resulting from handling and transport of patients. Data was collected using Nordic questionnaire and data analysis was performed by SPSS (ver. 16). The Questionnaires were completed for 46 personnel of the four parts of the hospital who complained a lot about musculoskeletal disorders, before and after the use of ergonomic stretcher designed and also the improvement of several rooms.Results: The main results of the initial investigations before the intervention, was a high prevalence of musculoskeletal disorders among personnel, especially disorders of lower back, shoulder and ankle, in which low back pain by %69.6 had the highest prevalence among personnel. The results of intervention by an ergonomic stretcher and improvement in layout of the hospital rooms significantly reduced the frequency and intensity of disorders.Conclusion: This study showed that the use of ergonomic equipment and proper layout of the rooms especially when the hospitals are designed, with proper training can significantly reduce musculoskeletal disorders resulting from patient handling.

Assessment of the ability of employees to work without risk to health and safety for themselves and others is the concept of job fitness. The five main criteria, i.e. work capacity, risk of health and safety, ethical indices, economic indicators and indicators of legal, occupational health physician must be considered in assessing fitness for work.This review article consists of different parts including: occupational fitness evaluation indices, safety and health risk, workers' capacity, legal and moral indices, economical index, evaluation tools, decision making process, consequences and challenges. Naturally, for each of the mentioned indicators there is a tool to assess the sensitivity, specificity and cost-effectiveness.Consequences of job fitness assessment can range from suitable to unsuitable. Changes in maintenance and adjustment of work or working conditions should be considered in assessing job fitness. But with all the explanations, in many cases an occupational health physician may face problems in decision making for job fitness. He/She may not be able to make a precise decision which is probably due to different causes such as lack of appropriate tools and atandards, workers' malingering, social laws and etc.