Journal of Occupational Hygiene Engineering
Year:2020 | Volume:7 | Issue:2|Papers Count:8

Background and Objective: Workplace air quality is a very important factor in community health, which is measured using airborne contaminants evaluation and measurement. One of these airborne pollutants in industries is ammonia gas. Spray towers are important components of air pollution control. This study aimed to investigate the effects of dilute sulfuric acid solution on the efficiency of ammonia removal in a spray tower. Materials and Methods: This study evaluated the rate of ammonia removal from the air stream using a spray tower with laboratory criterion by altering the liquid pressure and nozzles, as well as the inlet density. The volume of the used airstream was 3737. 82 l/min; moreover, one, two, and three 20micron diameter nozzles were used with the dilute sulfuric acid solution. The data were analyzed in SPSS software (version 21) through one-way ANOVA. Results: An increase in the number of nozzles and washing liquid pressure of the spray tower increased the ammonia removal efficiency and enhanced the input load of the system which reduced the elimination efficiency (P<0. 05). Conclusion: An increase in the number of nozzles, the operating pressure of the washing liquid, and the density of the pollutant gas lead to a higher level of spraying tower efficiency in terms of eliminating the ammonia gas from the air stream.

Background and Objective: The exposure of hospital personnel to anesthetic gases in various parts of health centers, such as operating rooms and recovery rooms, can exert serious effects on a person's physical and mental health. The present study aimed to investigate the effect of demographic variables on the prevalence of neurotoxic symptoms in operating room personnel. Materials and Methods: This cross-sectional study was conducted on 404 operating room personnel in western Iran. Euroquest questionnaire and demographic checklist were used for data collection. Data were analyzed in SPSS software (version 23) using t-test, ANOVA, and Pearson correlation. A p-value of 0. 05 was considered statistically significant. Results: Based on the obtained results, the rate of neurotoxic symptoms was higher in men, compared to women, and this difference was statistically significant. Nevertheless, no significant difference was observed between single and married employees and morning and shift staff in neurotoxic symptoms. Moreover, there was no significant correlation between neurotoxic symptoms with age and experience of the subjects. Conclusion: Symptoms were higher in some demographic groups; therefore, it is recommended to use appropriate training programs or management techniques, such as job rotation in operating room personnel.

Background and Objective: Medical diagnostic laboratories face a myriad of problems in the field of safety, health, and/or the environment (HSE) due to their sensitive functional characteristics. Therefore, the audit of these issues is of utmost importance. The present study aimed to evaluate EHS audit in medical diagnostic laboratories of North Khorasan province and their measurability among 37 public and private laboratories and 148 employees in 8 cities of this province. Materials and Methods: For the purpose of the study, a checklist (approved in the terms of validity and reliability) was used to assess the level of HSE audit. SPSS (version 24) and SMART-PLS software were used to analyze the obtained data. Results: As evidenced by the obtained results, the variables under study are in good condition in laboratories. Nonetheless, except for maintenance, the various dimensions of HSE audit have better conditions in public laboratories, compared to private ones. Moreover, it was found that different dimensions of HSE audit, except for sewage, are the same in different cities of the province. Conclusion: Current laws and inspections of medical laboratories of North Khorasan province, following the guidelines and directives of the Ministry of Health and Medical Education, are very well evaluated and implemented. Therefore, it can be concluded that public and private laboratories investigated in the present study were in good condition.

Background and Objective: Central oxygen is one of the vital parts of hospitals responsible for supplying oxygen. Therefore, any defect in this system can result in human and financial losses. Therefore, effective risk analysis is of utmost importance in the prevention and mitigation of such potential accidents. In the light of aforementioned issues, the current study aimed to analyze the scenarios of accidents in the oxygen central unit of the hospital using Fault Tree Analysis (FTA) and Layer Of Protection Analysis (LOPA) methods. Materials and Methods: In the first step, probable errors in oxygen leakage were identified and then FTA was plotted. Dangerous scenarios in central oxygen were identified and the risks were analyzed using the semiquantitative LOPA method. Finally, control measures were proposed to reduce oxygen leakage. and semi-quantitative LOPA method was used for risk analysis. Finally, control measures to reduce oxygen leakage were predicted Results: As evidenced by the obtained results, the most important accident scenarios include oxygen release, explosion, and fire. Independent protection layers are suitable for oxygen storage and production tanks, and the use of Independent Protection Layers (IPL) can significantly reduce the risk. The most important cause of leakage in the patient's room was due to the mask being removed from the respiratory area or the lack of fit with the patient's face. Conclusion: The results of this study showed that the independent protective layers in central oxygen are sufficient to prevent oxygen leakage. It is also necessary to use a sensor to determine the concentration of oxygen in the patient's room and a special alarm to increase the concentration of oxygen in order to reduce the risk of oxygen leakage in the environment. Furthermore, periodic training to all employees and maneuvers should be implemented in the crisis management measures in hospitals.

Background and Objective: Electrocutions are not very common; however, their consequences are severe. The present study aimed to analyze the parameters that affect electrocution accidents and evaluate the electrical safety of small-scale industrial workshops. Materials and Methods: This study was conducted in 2019 on the electrical accidents that occurred in 232 small-scale industrial workshops during a 7year period. The data collection tools included electrical accident report forms and a researcher-made checklist for the evaluation of the electrical safety of the selected workshops. Finally, the collected data were analyzed using Chi-square, Fisher, and regression tests. Results: According to the results, the rate of electrocution in 125 small-scale industrial workshops without safety (first group) measures was approximately 10 times higher than that of the 107 workshops that had safety measures (second group). Moreover, the disciplines in 79. 5% and 75. 0% of the workshops in the first and second groups were poor, respectively. Furthermore, it was found that 64. 1% and 50. 0% of the electrocutions in the first and second groups were caused by perceptual errors, respectively. Moreover, the rates of personal protective equipment (PPE) training in the first and second groups were 3. 2% and 44. 0%, respectively while the rates of PPE deployment were 5. 6% and 55. 1%, in the first and second groups, respectively. In addition, there was a significant difference between the two groups in terms of safety measures (P<0. 05). The results of modeling the parameters that affected the electrocution revealed that electrical safety training had the highest correlation with other variables. Conclusion: Based on the findings, it can be concluded that electrical safety was poor in small-scale industrial workshops. Therefore, it is recommended to use practical electrical safety training and implement safety systems, such as the grounding system and circuit breaker switches to help reduce electrocution accidents.

Background and Objective: Pulse jet baghouse systems are of interest due to their high filtration velocity. They are used as inlets from the top and bottom. The purpose of this study was to compare the pressure drop and collection efficiency at different inlet positions in a baghouse. Materials and Methods: In this experimental study, a pilot baghouse system was designed at 12ft/min permeability for MDF particles. For each inlet, after several filtration-cleaning periods, the pressure drop was measured by a manometer. Isokinetic sampling was carried out by Grimm monitor model 1. 108 for the determination of the efficiency. To observe the behavior and Tyndall effect of the particles, a light and safety glass were used in one dimension of the baghouse. Results: The mean of pressure drop during the filtration-cleaning was reported as 3 cmWG in the bottom inlet. In addition, the means of the topexpansion inlet and top-flanged inlet were observed to be 2. 42 and 2. 57 cmWG, respectively; however, the particles were settled on the bottom in the expansion. The efficiency means of the top-expansion and top-flanged inlets were 99. 995% and 99. 994%, respectively, which were significantly higher than that reported for the bottom inlet (99. 974%). Nevertheless, after several filtration-cleaning periods, the efficiency values of the bottom, topexpansion, and flanged inlets were obtained as 99. 99%, 99. 97%, and 99. 96%, respectively. There was no significant difference in the means of total efficiency among different inlets. Conclusion: The collection efficiency values were similar for baghouse with the inlet from the top and bottom. The pressure drop for baghouses with top inlets was lower than that reported for the baghouses with bottom inlets. It is recommended to use top inlets in case of predominantly fine particles with low density or in the presence of a pre-separator, and bottom inlets are suggested in case of large particles. However, due to the slight difference of pressure drop and more functional limitation of the top inlet, the bottom inlet is preferred in practice.

There is a need for a systematic approach to reduce the consequences of the coronavirus disease-2019 (Covid-19) outbreak. The most effective way to prevent this disease is to cut off the virus transmission chain. This study aimed to propose a systematic model for the management of the Covid-19 crisis based on the bow-tie analysis model and the concept of Layers of Protection Analysis from the perspective of safety engineering. In this model, five layers of defense have been introduced to reduce the patient's referral to the hospitals and effectively manage the disease transmission chain. In addition to maintaining the health of citizens, the implementation of this model will improve the health of healthcare workers by reducing the burden of patient admission to hospitals.

Background and Objective: Human error is the most common cause of accidents involving operating cranes in the construction industry. Operator errors are caused by various factors during crane loading operations. Success Likelihood Index Model (SLIM) is used as a simple and effective way to assess the probability of human error. Materials and Methods: In this study, the SLIM method was used to evaluate and manage the possibility of human error in loading operations by tower cranes. After forming the expert team, the factors influencing the errors in the operation of the cranes were identified in this study. Subsequently, the rate and weight of these factors were determined, and the probability of human error was calculated for each error using the total SLI. Results: Initially, six effective Performance Shaping Factors (PSF) influencing the operation of the tower cranes were determined by experts. Out of the identified PSFs, training obtained the greatest impact on the likelihood of human error. By calculating the probability of human error based on the calculated SLIs, it was found that the errors of obstacle collisions (1. 70×10-02 ), contact with power lines (1. 69×10-02 ), and overturns (1. 62×10-02 ) obtained the highest Human Error Probability in descending order. Conclusion: The results of this study showed that the highest probability of human error in crane loading operations is related to obstacle collisions. Moreover, the most effective PSFs in creating errors are training, conditions, tools, and experience. Therefore, the reliability and overall safety of the loading operations can be increased by planning and holding continuous training courses, updating instructions, and appointing highly experienced people as crane operators.