Journal of Health and Safety at Work

Introduction: IBioaerosols are usually defined as aerosols or particles with microbial, plant or animal origin. Textile industries are of the working environments in witch workers are exposed to bioaerosols. In textile industry, the highest contamination concentration is the belonged to carding step. Since, textile industry in iran is native and a large number of employers are working in this industry, this study was undertaken to assess bacterial bioaerosols concentration in a textile in industry in iran.
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Material and Method: In cross-sectional study was done in different units and also outdoor environment of a cotton textile plant. The concentration of bioaerosols were sampled and measured according 0800 method presented by NIOSH, during summer. Diagnosis of type of colonies and bactories, grown on blood agar, was done using gram staining.
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Result: The mean bioaerosols concentration obtained the highest and lowest values in outdoor environment (94±9.5 CFU/m3) and unit 2 (Ring site) (64±18.0 CFU/m3), respectively. The mean difference of bioaerosols concentration in unit 1 (Carding sites) and unit 2 (Ring site), was statistically significant in this study. The highest number of bioaerosols colony was for staphylococcus Epiderms (N=1743) and the lowest number was for streptococcus pneumonia (N=64) in the whole plant.
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Conclusion: Although the bioaerosols concentration obtained in the present study is lower than those reported in other studies, these values are above the threshold recommended.

Introduction: The present study was carried out to compare contrast sensitivity among three groups of professional welders including (1) those who use gas metal Arc welding (GMAW) (2) those who use shield metal Arc welding (SMAW) and the group that uses resistance welding.
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Material and Method: In this research, all the welders who use GMAW, SMAW and resistance welding working in an industry who were all male, performed contrast sensitivity test, using Freiburg. The contrast sensitivity test was done at three spatial frequency of 1cpd, 5cpd and 15 cpd under a constant condition. The three selected groups were similar regarding age and work experience. The result of the three groups at each spatial frequency were recorded and compared with other groups.
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Results: ANOVA test showed that decrease contrast sensitivity in spatial frequency of GMAW group at the spatial frequency 15cpd, significantly decrease comparing to SMAW group (p=0.028) and resistance welding group (p=0.041). The mean (SD) of contrast sensitivity at frequency of 1cpd, 5cpd and 15cpd was respectively 140.69±51.8, 172.7±43.75 and 39.8±25.92 for the GMAW group and 157.8±42.2, 183.21±32.01 and 60.57±54.30 for the SMAW group and 149.10±50.68, 180.60±35.42 and 57.38±39.22 for resistance welding.
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Conclusion: Although all welders use goggle or other personal protective equipment, loss of contrast sensitivity of GMAW workers can be attributed to the cumulative effects of the radiation.

Introduction: One of the factors influencing on indoor air quality of the buildings is performance of HVAC (heating, ventilation, and air conditioning) systems. These systems supply clean and odorless air, with temperature, humidity, and air velocity within comfort ranges for the residents. The aim of this study was to evaluate performance HVAC system in an administrative building in Tehran.

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Material and Method: A questionnaire, developed in their research was used to assess the building occupants’ perception about the performance of HVAC system. To evaluate the performance of HVAC systems, air velocities were measured in the diffusers using a thermal anemometer. Moreover, CO2 concentration, air temperature and relative humidity were measured in the whole floors of the building. Air distribution inside the building was evaluated using smoke test.

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Results: Most of the studied people complained about the direction of airflow, thermal conditions and cigarette odor. The highest level of carbon dioxide was measured at 930 ppm inside the restaurant. The maximum and minimum air temperatures and relative humidity were measured 28.3-13.8° C and 28.4-23% respectively. Smoke test showed that the air distribution/direction wasn’t suitable in one third of air diffusers.

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Conclusion: Improper air distribution / direction was the main problem with the studied HVAC system which could be corrected by adjusting and balancing of the system.

Introduction: Work conditions in kerbside ticket booths intensify the risk of health threats. In this research, it is aimed to introduce solutions for improving ergonomics conditions of these booths, by ranking and analysis the risk factors.

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Material and Method: Demographic information as well as physical, mental, and safety conditions of 47 booths are collected through questionnaires, interview and video recording. Following, critical index was identified using a hybrid method including QEC checklist, ANOVA statistical test and innovative methods for determining ergonomic indices. Improvement strategiesfor the critical index were analysed,using CATIA V5 R20 software and RULA technique, and solutions were presented.

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Result: Based on F-test at the 0.05 significance level, anthropometric characteristics and personal informationshowed no difference betweenmale and female vendors, except for weight. Comparison of ergonomic indices manifested the maximum occupational exposurefor physical-motor factors (45.39) and environmental factors (41.28). Additionally, the highest risks determined by Nordic questionnaire and QEC checklists belonged to arms and shoulders (38) and wrist (26). Three dimensional model of vender with current and suggested postures were analysed using RULA and accordingly it was found that risk levels were improved for right and left side of the vendor body from 7 and 5 to 3 and 1, and for customers from 6 to 1.

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Conclusion: Vendors of electronic ticket booths are exposed to musculoskeletal and environmental health threats, in Mashhad. Relocating the booths, adjustingcounterand desk height can significantly reduce the risk of mentioned hazards

Introduction: The bank employees usually require the use of computers for long duration in a static position to get the work done. The present study aimed to evaluate the risk factors for musculoskeletal disorder using the ROSA method among the employees of Sepah Bank. An ergonomic intervention was also performed in order to improve the working conditions.

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Material and Methods: This interventional descriptive-analytical study was carried out among 165 office employees of central building of Sepah Bank. Using random sampling, the subjects were initially divided into two groups of case and control. Before and after the intervention, ROSA method and Nordic questionnaire was respectively used to evaluate the risk factors that cause musculoskeletal disorders and the prevalence of musculoskeletal disorders. The data were collected two weeks prior the interventions and 9 months after the interventions. SPSS software version 16 was utilized for data analysis and the effectiveness of intervention was determined.

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Results: Before the intervention, the mean ROSA scores of all groups' workstations were above 5 with high risk. The results obtained 9 months after the interventions manifested a statistically significant decrease (P<0.001) in the ROSA mean scores and its components in the groups who received the interventions. 9 months after the intervention, the prevalence of musculoskeletal disorders among the subjects who had received intervention showed a significant reduction, as well (0.001> p).

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Conclusion: Using the ROSA technique was seemed to be beneficialto assess the ergonomic risk factors of office works, and the deficiencies in the workstation can be identified through this method. Moreover,by design and implementation of an educational intervention program along with engineering interventions which comply with the elements of this technique, the defects can be eliminated.

Introduction: Each year tens of millions of labors are victims of occupational incidents leading to the disablement or death of many of them. The present study has been conducted with the aim of predicting the performance monitoring indicators of incident after implementation of the integrated management system in order to reduce number of incidents, safety monitoring, and giving priority to safety programs in the organization policies.

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Matherial and Methods: Using safety performance indicators, this descriptive-analytical study has been done in two stages in a combined cycle power plant on 254 incidents before the implementation (2004) and the years after the implementation of integrated management systems(a seven year period). The required data was gathered through checklist and interview with the injured workers. Kolmogorov-Smirnov, Chi Square, and Cubic regression tests were utilized for data analysis at significance level of 0.05.

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Results: Of the 1131 labors during a seven year period, 254 occupational incidents were recorded. The highest value of accident frequency rate was in 2004 (32.65) while the highest accident severity rate was in the year 2008 (209). Moreover, the lowest frequency rate and severity rate were related to the year 2011 with value of 9.75 and 29.26, respectively. Regression graphs, between the observed values and the estimated values, showed that the coefficients of all the indicators, except for β1of ASR,are significant(P< 0.05) as expected. This result implies the improvement in the safety performance and integrated management systems.

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Conclusion: Findings show that Cubic regression can be an appropriate to olforinvestigating the indicators trends and for their predictionin planning and monitoring the performance ofsafety unitso that the decision-making for determining the priority of organizations’ safety programs would be facilitated.

Introduction: Installation of wind turbines in residential areas due to their unique sound characteristics may cause noise annoyance. Noise annoyance can increase the risk of health problems and sleep disturbance. Thus, this study was conducted to assess the effect of wind turbine noise annoyance on sleep disturbance among the Manjil wind farm workers.

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Material and Method: All the Manjil wind farm workers have been divided into three groups according to their noise exposure levels, including maintenance, security, and administrative workers. The equivalent A weighted noise levels were measured for each of the study working groups, using ISO 9612 standard method. Information related to the noise annoyance and sleep disturbance were determined by ISO15666 standard and the Epworth Sleepiness Scale, respectively. Data were analyzed using R software.

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Result: Findings of ANOVA and Kruskal-Wallis statistical tests showed that noise annoyance and sleep disturbance were statistically different among workers with various occupational, age, and work experience groups. Also, noise annoyance and sleep disturbance had a significant association in a way that regardless of the effects of other variables, it can be stated that for every one unit increase in noise annoyance, 0.26 units will be added to the amount of sleep disturbance.

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Conclusion: In this study, workers with more wind turbine noise annoyance had more sleep disturbance. Therefore, in addition to the direct effects of noise on sleep disturbance, it can indirectly exacerbate sleep disturbances.

Introduction: In Laboratory accusations a wide range of hand-held tools are used due to nature of their work. Long-term and repeated use of these tools has led the laboratory workers to suffer from upper limb disorders. The present study was designed and implemented with the aim of investigating the usability of different models of pipettes used in the laboratories of the Tehran University of Medical Sciences, employing subjective assessment methods for selecting the best pipette models.

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Material and Method: This cross-sectional and analytical-descriptive study was performed among 35 laboratories employees of Tehran University of Medical Sciences. First, four models of the widely used pipettes were selected and their usability-related characteristics were investigated by a visual analog scale (VAS). Judgments concerned the usability of the pipettes done based on the criteria provided by the International Organization for Standardization 9241-11(1998) and 20282-2(2006). Data analysis was performed, using SPSS software version 22.

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Result: The overall evaluation of the users in relation to the characteristics of the pipettes indicated that the highest VAS score was belonged to pipette A, C, and D, respectively. Furthermore, pipette B was selected as the most undesirable one by users. Results related to the usability criteria of pipette showed that of the four models of study pipettes, pipette A has been ranked first in two criteria (satisfaction and effectiveness). Regarding the efficiency, the first rank was for C pipette and the second rank was for pipette A. Pipette B obtained the lowest scores for all given criteria.

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Conclusion: Shorter and lighter pipettes, which were designed according to ergonomic principles, had greater usability from the perspective of users and it could cause a better subjective assessment comparing to the other models.

Introduction: During recent years, carcinogenic effects of X-ray have been proven. Todays, lead is used in many equipment such as  coats, thyroid shield, and gloves for body protection against X-ray. However, these equipments have several disadvantegous including toxicity, heaviness, and inflexibility. Hence, newer methods like protective semisolid products (cream, ointment) for topical application are being replaced. Therefore, the feasibility of using an ointment containing bismuth oxide nanoparticles (Bi2O3) as a X-ray adsorbent was evaluated in this study.
 

Methods and Materials: First, synthesis of Bi2O3 and then formulating it in the form of ointment was investigated. In this study, X-ray device and dosimeter was employed to check the X-ray absorption in different thickness of bismuth oxide nanoparticles ointment.
 

Results: In dosimetry test, the protective effect of the ointment containing Bi₂O₃ nanoparticles was evaluated significantly (P<0.05) better than control group and equal sheet lead group. Dosimetry tests showed that the bismuth oxide nanoparticles ointment and cream absorb  56% of the radiation whereas this value is  41% for lead. K absorption edge for bismuth is higher than other metals and its nanoparticles have more absorbent surface to volume ratio (S/V).
 

Conclusion: It seems that due to higher atomic number and lower toxicity, Bi₂O₃ nanoparticles have better efficiency in X-ray absorbtion, comparing to the lead. Cream and ointment of bismuth oxide nanoparticles can be used as X-ray absorbant for different professions such as physicians, dentists, radiology experts, and operating room staff and consequently increase health and safety of these employees.

Background: High prevalence of musculoskeletal disorders have been reported by office workers due to the nature of their work. This study aimed to evaluate the prevalence of musculoskeletal disorders in a group of office workers and also to determine the ergonomics risk factors affecting these disorders.
 

Methods: This is a cross-sectional study, performed among 174 office workers in Kerman city, Iran. Data collection tools included demographic and organization information form, the Nordic Musculoskeletal Questinnaire (NMQ), and the Rapid Office Strain Assessment (ROSA) method. The gathered data were analyzed by SPSS software version 16 using descriptive statistics, chi-square test, and logistic regression.
 

Findings: The prevalence of symptoms of musculoskeletal disorders (MSDs) in the past 12 months was reported 60.4 percent. What is more, significant associations were observed between job tenure and hours a day using computer with MSDs (P-value<0.05). In this sense, with  one unit increase in job tenure (years) and duration of computer use (hours per day), the probability of incidence of MSDs gone up 17.2 percent and 15.8 percent, respectively. Based on the statistical chi-square test, a significant relationship was reported between the incidence of MSDs and Rapid Office Strain Assessment method (P-value<0.05).
 

Conclution: According to results, ROSA assessment method is an efficient tool in the classification and identification of factors affecting the incidence of MSDs among office workers. Performing corrective measures in the dangerous work stations (the second level identified by ROSA technique), reducing the duration of computer use per day, and doing regular sport activities can be noted in order to decrease the prevalence of MSDs in the study group (office workers).

Introduction: Safety climate is the perception of personnel about the priority of safety in an organization. The objective of this study was to evaluate safety climate using Nordic questionnaire in a hospital.

Material and Method: In this cross-sectional study, 92 nurses working in different wards of a hospital in uromia city, Iran, filled out the NOSACQ-50 questionnaire. The responses of nurses were recorded with a 4-point Likert scale. The results were analyzed using descriptive and analytical statistics.

Results: Seventy-two percent of nurses were female and the remainders (28%) were men. The mean score of safety climate dimensions was different. “Management safety priority, commitment, and competence” and “Safety communication, learning, and trust in co-workers safety competence” dimensions obtained the lowest and the highest scores by nurses, respectively. The mean score of safety climate ranged 2.49 to 2.67 in different wards of the hospital. What is more, the mean safety climate was not statistically differed among nurses of various age and work experience categories (P-value> 0.05).

Conclusion: According to the results, it can be noted that the level of safety climate in the hospital was fairly good from the nurses’ viewpoint. However, attempts should be made to improve it, especially in the safety management related dimensions. Corrective control measures should be implemented in all wards of the hospital for all personnel with any age and work experience.

Introduction: Resilience engineering (RE), as a new approach in the system safety domain, is intended to preserve the performance of socio-technical systems in various conditions; and accentuates the positive activities instead of the failure modes. The aim of this study was to develop a new framework for safety assessment on the basis of RE, using the Fuzzy Analytical Hierarchy Process (AHP) method.  

Material and Method: Current study is an analytical cross-sectional survey performed in a petrochemical industry. Initially, six RE indicators were selected, including top management commitment, just culture, learning culture, awareness, flexibility and emergency preparedness and accordingly an assessment framework was established. Then, the selected RE indicators were evaluated and validated by experts in a specialized panel. Following, an indicator was proposed named “resilience early warning indicator”. Finally, the RE indicator score of the total process was determined using the fuzzy evaluating vector.   

Result: Findings revealed that top management commitment and learning indicators have the most and the least effects on the RE level of the process, respectively. Besides, the flexibility (C3) indicator was located in orange early warning zone (OEWZ) while other indicators were positioned in the no early warning zone (NEWZ). Furthermore, the overall resilience level of the process was evaluated as level III (NEWZ).

Conclusion: Management commitment and emergency preparedness are two main indicators of RE and can carry out the most important effect for remaining the RE in the NEWZ level.

Introduction: Nowadays, exposure to extremely low frequency (ELF) magnetic field has been interested in many studies due to possible effects on human physical-mental health. Therefore, this study aimed to assess arc welders’ exposure to extremely low frequency magnetic field and to determine its relationship with the secretion of paratormone (PTH) hormone and mood states.

Material and Method: The present study has been conducted among 35 healthy production workers (as exposed group) and 35 healthy administrative personnel (as unexposed group). After checking the work activities of participants according to the guide recommended by the National Institute for Occupational Safety and Health (NIOSH), ELF magnetic fields were measured using an ELF measurement device in the regions including trunk, head, and neck. The plasma levels of PTH hormone of both groups were evaluated by the Electrochemiluminescence method. Stress-Arousal Checklist (SACL) was used to assess the mode states of subjects in both groups. The collected data were analyzed by SPSS software version 16.

Result: There was a significant difference between the exposed and unexposed groups with respect to the exposure level to ELF magnetic fields (P-value<0.0001). Mean PTH hormone level in exposed group (34.54 pg/ml) was lower than unexposed ones (37 pg/ml), however these mean values weren’t significantly different (P-value=0.67). Score of “stress” subscale related to the “pleasure” and score of “arousal” subscale  related to the “activities and alertness” in the unexposed group were significantly higher than those in exposed group (p<0.0001). Regarding the relationship between exposure level to ELF electromagnetic field and scores of  stress, arousal, and PTH hormone level in the two groups, it should be stated that only a significant and positive association was found between the average exposure to ELF magnetic fields and PTH levels in the exposed group (P-value<0.009, r=0.44).

Conclusion: The results of this study showed that continuous welding can be considered as an exposure source to extremely low frequency electromagnetic fields. More accurate and comprehensive laboratory and field studies are needed to prove the hypothesis of the potential impact of extremely low frequency magnetic fields on people’s psychological states and mood through changes of parathyroid hormone level.

Introduction: Nowadays, Shielded Metal Arc Welding (SMAW) is the most widely used arc welding. During the welding operation, typically, various harmful agents such as fumes, gases, heat, sound and ultraviolet radiation are produced of which fume is the most important component from the viewpoint of occupational health. The present study aims to compare the number and the mass concentration emitted in SMAW to determine the most appropriate index of exposure to fumes in the welding processes.

Material and Method: In this study, the portable laser aerosol spectrometer and dust monitor of GRIMM, model 1.106, was used to measure the number and mass concentration of fumes emitted from SMAW on 304 stainless steel with a thickness of 0.4 mm. Air sampling was performed at a distance of 41 cm representing the welder’s breathing zone. The measurements of number concentration (NC) and mass concentration (MC) were taken under the condition of 25 volt voltage and direct current of the electrode polarity.

Result: The total NC and MC of welding fumes in welder’s breathing zone was 1140451 particles per liter and 1631.11 micrograms per cubic meter, respectively. The highest number concentration was found to correspond to the particles with 0.35 to 0.5 micrometer-sized distribution (NC1; 938976 particles per liter) and the lowest was related to the particles with 5 to 6.5 micrometer-sized distribution (NC7; 288 particles per liter) and the particles larger than 6.5 micrometer (NC8; 463 particles per liter). Moreover, the highest mass concentration was related to the particles with 0.35 to 0.5 micrometer-sized distribution (MC1; 450 micrograms per cubic meter) and the particles larger than 6.5 micrometer (MC8; 355 micrograms per cubic meter).

Conclusion: The findings indicated that there is no agreement between number and mass concentration as two particles assessment index, and as the particles’ size become smaller, the mismatch of them is becoming more apparent. Since the smaller particles penetrate into the lower respiratory tract and have higher potential for adverse health effects, it is necessary to measure and assess particles in various size distributions and especially the smaller fraction of particles. Therefore, it is thought that considering the mass concentration alone and not paying attention to number concentration in the assessment of exposure to particles in the industrial workplaces and specifically in welding stations will not be reflected valid assessment of adverse health effects of welding fumes as a systemic poison on body organs.

Introduction: Due to the importance of engineering controls for prevention of microwave exposure, this study was conducted to design and constract a novel electromagnetic shielding and also to examine the factors influencing shielding efficacy in X band frequency range.

Material and Method: This study used Resin Epoxy as matrix and nano-Nickel Oxide as filler to prepare the composite plates with three different thicknesses (2,4, and 6 mm) and four different weight percentages (5,7,9 and 11). The fabricated composites characterized using X-ray diffraction and Field Emission Scanning Electron microscopy. Shielding effectiveness, percolation depth, and percolation threshold were measured using Vector Network Analyzers. Thermal Gravimetric Analysis was conducted to study the temperature influence on weight loss for fabricated composites.

Result: A maximum shielding effectiveness value of 84.18% was obtained for the 11%-6mm composite at 8.01 GHz and the 7%-4mm composite exhibits a higher average of shielding effectiveness of 66.72% at X- band frequency range. The 4mm thickness was optimum and critical diameter for composite plates; and percolation depth was obtained greater than thickness of composites. However, increasing the nickel oxide content did not show noticeable effect on the shielding effectiveness. Thermal Gravimetric Analysis showed that the study shields were resistant to temperature up to 150 °C without experiencing weight loss. What is more, the results indicated that Nickel oxide Nano particles had desirable distribution and dispersion in epoxy matrix and percolation threshold was appeared in low content of nickel oxide nanoparticles.

Conclusion: A novel electromagnetic shield using low thickness and few content of nanoparticle with noticeable efficacy was properly designed and constructed in the field of occupational health. In addition, this shield has low cost, easy to manufacture, resistance to wet/corrosion, and low weight. Epoxy/nickel oxide composite can represents a new generation of electromagnetic shielding, which is considered as a promising candidate for occupational protection against microwave exposure. It is recommended that future studies improve the shielding effectiveness by decreasing the percolation depth and investigate the efficacy of the fabricated shield in the workplaces.

Diazinon is commonly used for pest control in the agricultural fields because of its relatively low cost and high efficiency. Due to the increasing application of pesticides, reliable and accurate analytical methods are necessary for their monitoring. This work was aimed to design the high selective electrochemical sensor for determining of diazinon in biological and environmental samples. The composition of sensor was modified with multi-walls carbon nanotubes and a molecularly imprinted polymer (MIP). A diazinon MIP was synthesized and applied in the carbon paste electrode (CP). The prepared sensor was used to determine the concentration of analyte. Parameters affecting the sensor response, such as sample pH, electrolyte concentration and its pH, and the instrumental parameters of square wave voltammetry, were optimized in different levels to select the optimum conditions for analysis of diazinon. The MIP-CP electrode showed very high specificity for determining the analyte. The obtained linear range was 1×10-6 to 5×10-10 mol L-1. The detection limit was 2.7×10-10 molL-1. This sensor was successfully used to determine the diazinon in environmental and biological real samples without special sample pretreatment before analysis.

Introduction: To evaluate heat stress in the workplace different indices are used. But, none of these measures have been widely accepted. The aim of this study was to determine effective criteria in selecting a heat stress index and weighting of these criteria.

Material and Method:  This study is a qualitative study that was designed and conducted within 10 stages. In the current study, effective criteria for choosing a heat stress index was determined by using Delphi technique and expert’s opinions (30 people), and then the fuzzy analytic hierarchy process was used for weighting and prioritization of these criteria.

Results: Analyzing the completed questionnaires by the experts and according to the percentage of respondents, 11 criteria were finally selected. “Simplicity” criteria by %76.6 had the highest percentage of response. But, the relative weight of this criteria was 0.041, and had the lowest weight after the “low cost” criteria.  The criteria relating to the “Standard” item was 0.141as the highest relative weight.

Conclusion: It can be concluded that the first step to have a reliable and accurate measurement is to choose a proper and correct index. Based on specialists and expert’s opinions, standardization of the index is the most important selection criteria. Other criteria that must be considered were accuracy, reliability and good correlation with the physiological strain indices.

Introduction: Nowadays, HEPA filters is used in hospitals, clean rooms, microbiology hoods, ventilation of surgery rooms, and Pharmacy for removing microorganisms and reduce health hazard. The aim of this study is to increase the efficiency of HEPA filters with UVC radiation to reduce the density of airborne microorganisms.

Material and Method:  The closed–loop chamber was made to evaluate Staphylococcus epidermidis, Bacillus subtilis bacteria and Aspergillus Niger, Penicillium fungi. The concentration of fungi and bacteria suspension Respectively was 106, 107 CFU/ml. After the suspension was prepared, it was sprayed into the closed loop chamber by nebulizer. Sampling was done with UVC radiation (1.8 mW/cm2 Illuminance) and no radiation (dark) that included time periods 60, 90 and 120 minutes. Microorganisms density was determined in term of CFU/m3.

Result: The result showed that there was a significant difference between UVC radiation and dark section for all the microorganisms (epidermidis, subtilis, Niger and Penicillium) at each time periods (P value< 0.05). This indicates that concentration of four microorganisms were decreased at all the time periods. UVC radiation could change the essential molecular substances for cellular factor. UVC can penetrate the cell walls of microorganisms. thus nucleic acids and other cellular vital material affected and will cause the destruction or inactivation of microorganisms.

Conclusion: UVC radiation is effectiveness to decrease concentration of four microorganisms. because UVC radiation could remove both bacteria and fungi. While the other studies in other countries, UVA radiation is only effective in reducing bacteria. Therefore, achieved greater efficiencies of HEPA filters, using HEPA filters with UVC will have a significant effect on reducing the density of microorganisms.

Introduction: Given the increase of road transportation of dangerous materials, if an accident occurs, the first groups that present at the scene are rescue groups (emergency، red crescent and firefighters). The aim of this study was to investigate the validity and reliability of the questionnaire assessing level of knowledge in the rescue personnel regarding warning signs mounted on the road heavy machinery.

Material and Method: Firstly, a multiple-choice questionnaire was designed using the literature and material safety data sheets (MSDS). Validity of the questionnaire was examined using the viewpoints of 10 experts. The reliability of the questionnaire was assessed using test-retest in 20 subjects of the rescue groups in two-week intervals. The cut point of the questionnaire was determined by the Receiver Operating Characteristic (ROC).

Result: The mean of age and work experience of the participants was 32.42 ± 2.57 and 7.75 ± 2.70. The results of correlation between the questions of the test showed that Cronbach’s alpha is 0.708. Also, the stability and reliability of test scores over time showed that the correlation between the questions in the first and second series was significance at acceptable level (r=0.698 with P-value=0.012(. The best value of cut point in the questionnaire of knowledge in the rescue personnel as obtained 18.5, with the sensitivity of 60% and specificity of 50%.

Conclusion: The validity and reliability of the knowledge assessment questionnaire in the rescue personnel were confirmed regarding the warning signs mounted on the road heavy machines; therefore, it can be used in the future studies.

Introduction: Hospital acquired infections recognize as an important risk factor in health care. In this regard health care and hand hygiene is the first step in controlling the infections. This study, carried out with the aim of comparing the effect of hand washings in the usual way with disinfectants without water in microbial contamination of the hospitals hand nurses.

Material and Method: Accordingly, samples were taken from hand of 30 nurses in the wards of surgery, pediatrics, emergency, CCU, ICU and cardiology in 4 steps before and after washing with soap and washing with liquid hand rub. Samples were cultured in EMB and Blood Agar medium, then identified by gram staining, catagase and coagugas tests and growth on manitol salt agar.

Result: The findings showed that 30 samples were not grown on EMB medium، but 30 samples of Blood agar, before and after washing with soap and  liquid hand rub, were grown and applying hand rub alcohol liquid is most effective than washing with soap. Identification of bacteria in manitol salt agar medium and coagulas test revealed %80 were coagulas negative staphylococcus and %20 coagulas positive staphylococcus.

Conclusion: In this study washing with soap dose not effect on hand hygiene of nurses but disinfectant with liquid alcohol shows significant correlation in reducing microbial load on personnels’ hand that is revealed alcohol was more effective in reducing pollution.