Journal of Health and Safety at Work

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Introduction: Volatile organic compounds from industrial activities are one of the most important pollutants released into the air and have adverse effects on human and environment. Therefore, they should be removed before releasing into atmosphere. The aim of the study was to evaluate xylene removal from air by nano-grapheme and nano-graphene oxide in comparison with activated carbon adsorbent.

Material and Method:  After preparing adsorbents of activated carbon, nano-graphene, and nano-graphene oxide, experiments adsorption capacity in static mode (Batch) were carried out in a glass vial. Some variables including contact time, the amount of adsorbent, the concentration of xylene, and the temperature were studied. Langmuir absorption isotherms were used in order to study the adsorption capacity of xylene on adsorbents. Moreover, sample analysis was done by gas chromatography with Flame Ionization Detector (GC-FID).

Results: The adsorption capacities of activated carbon, nano-graphene oxide and nano-graphene for removal of xylene were obtained 349.8, 14.5, and 490 mg/g, respectively. The results of Scanning Electron Microscope (SEM) for nano-graphene and nano-graphene oxide showed particle size of less than 100 nm. While, the results of Transmission Electron Microscope (TEM) showed particle size of 45nm for nano-graphene and 65 nm for nano-graphene oxide. Also, X-Ray Diffraction (XRD) showed cube structure of nano-adsorbents.

Conclusion: In constant humidity, increase in exposure time and temperature caused an increase in the adsorption capacity. The results revealed greater adsorption capacity of xylene removal for nano-graphene compared to the activated carbon, and nano-graphene oxide.

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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.

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Introduction: Nowadays, many modern industries require an environment with no contamination by particles and bacteria. An enclosed clean room environment is a place where parameters such as airborne particles, temperature, humidity, air pressure and air flow pattern is controlled. The aim of this study was to evaluate functional parameters of a clean room  in a selected pharmaceutical industry.  

Material and Method: This study was an experimental study conducted in 2015 in a pharmaceutical industry.  The air flow rate and flow rate with airflow capture hood was used and multi sensor devices for measuring temperature, humidity and pressure of multi-sensor device. HEPA filter leakage test and counting concentration of particles in the cleanroom was done according to the ISO 14644 – 3(2005) standards using aerosol photometer and aerosol generator. In this study, 6 clean room relating to the 3 cleanliness classes B, C and D (in accordance with standard EU GMP) were evaluated. Meanwhile, both the 2 and 3-dimensional flow model using Computational Fluid Dynamics Software was simulated in this study.   

Result: Measuring the parameters flow rate and air velocity, temperature (average temperature 20 ° C), relative humidity (below 50%), pressure (pressure less than 15 psi) for every three classes of cleanliness are all acceptable and less than the proposed standard. Furthermore, the results of modelling showed that the pattern of air flow in the room is correct paths in circulation. In the case of leakage test filters, the filter 29 filters tested 5 was leaking and ultimately determine the HEPA filters remove particles that average efficiency is 99.99%.

Conclusion: This study showed that the high volume and good quality of air entering the clean room affect the optimal efficiency and air flow rate, pressure drop and air penetration of the HEPA filters Also, the results of study show that the concentration of airborne particles in clean room is depend on the air flow rate and speed and adopting a good air flow pattern will affect the particle concentration.

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Introduction: Correspondence analysis method and preparation of accidents and occupational hazards pattern is able to predict and anticipate accidents and is automatically prioritize the risks and injuries. The aim of this study was to present accidents and occupational hazards pattern based on risk-injury groups, which use it to manage of occupational accidents.

Material and Method: The report of occupational accidents, registered in the social security organization was collected in a period of ten years from 2005 to 2015 (222,300 accidents). Types of risk and injuries to any of the accidents specified based on International Labor Organization criteria and risk of injury were classified in a matrix (18 × 18). Risk-injury groups were separately identified using correspondence analysis and collapse process, as patterns of accidents and occupational hazards. In the mentioned patterns, the relationship between risks and damage can be identified, as it facilitates decision-making in risk assessment in companies covered by the social security organization.

Result: According to the findings, three groups of occupational accidents were obtained and variables of these three groups extracted from the obtained patterns. The first group included six risks and seven injuries that the risks variables were: contact with hot materials, accidents caused by caustic  and corrosive substances, contact with chemicals, accidents caused by toxic substances, contact with electrical equipment, explosion and fire, and injuries were: burns, other injuries, multiple injuries, gas poisoning, suffocation, poisoning, environmental hazards. The second group included seven risks and six injuries that the risks variables were: accidents caused by displacement, projections of fragments or particles, accidents caused by machine tools, slipping, falling people, falling objects, other accidents and injuries were: twists and sprains, dipping the objects in the body, objects in the eyes, cuts and amputations, superficial wounds, deep wounds. Finally, the third group included five risks and five injuries that risks variables were: Falling under the rubble, accident with vehicle, accidents caused by displacement, colliding of persons against objects, projections of fragments or particles, accidents caused by manual tools, trapped between objects, accidents caused by machine tools and injuries were: fractures, dislocation, back pain, hitting, contusions and crushing. It should be noted that the study of these patterns can be used to identify and prioritize of occupational accidents.

Conclusion: The proposed groups make new opportunities for development of the applications to analyze, interpret and automate management of occupational accidents in order to minimize uncertainty and increase its objectivity. Its advantage over other similar analyses can be considering both the risks and injury and to obtain groups of two variables. Due to the frequency and distribution of mass of risk and injury variables in the groups, the risk and injury variables of group 3 are the most important, and the risk and injury variables of group 2 are less important and the risk and injury variables of group 1 have the least importance.

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Introduction: Extensive human and economic losses due to the fire accidents shows the necessity of scientifically dealing with major industrial fires, , investing in the development of fire protection technologies and determination of the most effective techniques to limit damages. This study is conducted to evaluate the effect of active and passive protection methods on reducing the level of fire risk, in the control room of a thermal power plant.

Material and Method: In the first phase of this study, fire risk level for buildings, goods, occupants and activities was calculated using Fire Risk Assessment Method for Engineering. In the second phase, from 36 sub-factors affecting risk level, three sub-factors of passive protection measures and two sub-factors of active protection measures were analyzed and modified, in reducing the fire risk level of occupants.

Result: The results of the present study showed that occupants’ fire risk level (20.64) is above the acceptable level. Correction of three sub-factors, including constant fire load, floor number, and changing the dimensions and area of the control room up to 40% and installing an automatic fire extinguishing system and training the occupants to use fire extinguishing equipment and emergency evacuation up to 33%, is effective in reducing the fire risk level.

Conclusion: Passive and active protection methods, despite their impacts on reducing the level of risk, cannot provide an acceptable level of fire safety independently. Therefore, combined use of these methods is essential to protect buildings and people, and prevent any interruption in the system’s activities.

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Introduction: Occupational health is one of the important issues that can affect productivity and economic development of an organization. This study aimed to determine the effect of didactic interventional Ergonomic-Safety program on workers’ productivity of an assembling industry.
Methods and Materials: This interventional study was conducted on 54 workers of assembling part of an electronic industry. Firstly, QEC method was used for Ergonomic assessment of work place and Hersey-Goldsmith questionnaire was applied for assessment of productivity. Then a comprehensive program was provided using findings of first stage assessment and identifying of existing failures. Second assessment of Ergonomic condition and productivity was done again by using QEC method and Hersey-Goldsmith questionnaire within three month of interventions. Data was analyzed by using of R software.
Results: Mean total productivity score and mean whole body score of QEC were 75.24 and 99.40 in before intervention phase respectively. In after intervention phase, Mean total productivity score and mean whole body score of QEC were 80.16 and 97.92 respectively. Data analysis by paired-samples t-test shows that difference of productivity score in before and after intervention phase was significant (P-value˂0.05). But difference of whole body score of QEC score in before and after intervention phase was not significant (P-value>0.05).
Conclusion: Accomplishment of Ergonomic-Safety intervention had a positive effect on productivity score whereas had not significant effect on general condition of body limbs.