Journal of Health and Safety at Work

Introduction: The human factor played major role in the accident causation. Statistics show that human error and human mistake are the primary cause for more than 80 percent of the accidents in petrochemical industry.The aim of this study wasidentification and assessment of human error due to unsuitable design which causeaccident and damage to the equipment in thesour water and SRP unit of arefinery plant.

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Material and Method: This research was qualitative case study to identify and assessment of human errors of worker in the control room of sour water within a oil refinery plant. The group of tasks with potential to causing accidents wereidentifiedby direct observation of activities and documents and individual interview. Hierarchical Task Analysis method (HTA) was used tojob analyze and the results were presented in HTA charts. All possible human errors in work stages were identified and assessed using SHERPA method.Action Errors, Checking Errors, Retrieval Errors, Communication Errors, Selection Errors were analyzed and their related data were entered in SHERPA work sheet.

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Result: The findings showed that from all of the 118 identified errors 50% were Retrieval, 22/22% wereAction Error22/22% Communication and 5.55% Selection Error.

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Conclusion: To prevent and control occurring each of the identified errors and to limit the consequences of them, appropriate counter measures such as proper control measures in the form of changes in design, including install the appropriate colored tag, digital indicator and warning lights which must be used base on the kind of system consequently, of this study showed that SHEPA can be an efficientmethod to study humanness in operational site.

Introduction: Nowadays,industries managers face to lots of information from internal and external sources in one hand,challenges andthreats in the other hand, that need proper decisions to fix the problems. One of the most important challenges in developing countries is selecting and coordinating Health, Safety and Environment program proportional to organizations needs. Because, organizations have life cycles with special characteristics and needs like human.

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Material and Method: In this article life cycles characteristics used to proper corporate life cycle questionnaire, and organizations separate to 5 categories according to their life cycles.Then, we compare HSE programs that were required to the organization life cycle with score cards results that shows available HSE programs in studied organizations, and offer suggestions to perform programs proportional to corporate life cycles.

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Result: Corporate life cycles questionnaire with 10 indicators, available HSE programs score cards with 47 indicators according to OGP model and corporate life cycles proper programs table were results of this article.

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Conclusion: The results showedweakness in the HSE programs implementation.Therefore, we offered the management methods like upgrade HSE culture and leadership for modification.

Introduction: In the steel industry,air blowers used to supply compressed air are considered as sources of annoying noise. This study aims to acoustics analysis of theairblower workroomand sound source characteristics in order to present noise controlmeasuresinthe steel industry.

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Material and Method: Measurement of noiselevel and its frequency analysis was performed usingsound levelmetermodelof CASELLA-Cell.450. Distribution of noise level in the investigated workroom in form of noise map was provided using Surfer software. In addition, acoustic analysis of workroom and control room was performed in view point of soundabsorption andinsulation. Redesignofdoor and window of controlroom and installation of soundabsorbing materialson theceiling of the workroom were proposed and the efficiency of these interventionswasestimated.

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Result: The totalsound pressurelevelin the blower workroom was 95.4 dB(L) and the dominant frequency was 2000Hz. Sound pressure level inside the room control was 80.1dB(A). The average absorption coefficient and reverberation time in the blower workroom was estimated equal to 0.082 Sab.m2 and 3.9 seconds respectively. These value in control room was 0.04 Sab.m2 and 3/4 seconds respectively. In control room, sound transmission loss between the two parts of the wall dividing was 13.7 dB(A). The average of noise dose in blower operators was 230%. With the installation of sound absorber on ceiling of workroom, average of absorption coefficient can increase to 0.33 Sab.m2 and sound transmission loss of the new designed door and window was estimated equal to 20dB.

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Conclusion: The main cause of noise leakage in the control room was insufficient insulation properties of door and windows. By replacing the door and window and installation of sound absorbing on ceiling of workroom, the noise dose can reduce to 49.6%. New Improved door and window of control room can reduce noise dose to 69.65% solely.

Introduction: Job satisfaction is a feeling of increased motivation, productivity and growth of personnel at work. Considering the negative effects of burnout, this syndrome can effect on occupational functions, such as quality of work, public health and job satisfaction. This study investigated the relationship between job satisfaction, general health and burnout is one of the automotive industries.

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Material and Method: This study was a descriptive - analytical study conducted among. 120 workers in an automobile manufacturing industry in Tehran.the samples were selected using simple sampling method. Data were collected using, job satisfaction questionnaire Barry field, GHQ-28 and self-evaluation scale questionnaire. The data were analyzed using SPSS software.

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Result: In this study 95% of individuals had low job satisfaction and moderated. In addition, 73/6% significant of people were likely to burnout, and 55% were people with mental health disorders. There was Inverse relationship between job satisfaction and general health the whole item. The direct correlation between the variables of general health and burnout, and there was a significant variable. The inverse relationship between job satisfaction and burnout, there was significant.

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Conclusion: Given the obvious relationship between burnout and job satisfaction with public health, industry executives need to learn and improve incentive programs to promote employment, human relations and feelings of efficacy and bring into force.

Introduction: There are different methods for controlling gaseous pollutants formed from air pollution sources that one of the most economical and efficient of them, is bio-filtration. The purpose of this study is Toluene removal from airstream by using the pure Pseudomonas putida bacteria as a fluidized bed in a two phase partitioning stirred tank bioreactor.Toluene ( Metyle benzene) is one of the aromatic compounds which uses as a chemical solvent.low to moderate concentration of Toluene causes fatigue, dizziness, weakness,unbalance behaviour, memory loss, insomnia, loss of appetite, loss of vision and hearing.

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Material and Method: In this experimental study at first, pure Pseudomonas putida in an aqueous phase containing nutrients and trace elements solution was duplicated and accustomed with Toluene. then solution contained microorganisms with 10% silicon oil was entered to bioreactor. The amount of CO2 and pollutant concentrations in the entrance and exhaust of bioreactor containing Pseudomonas putida was studied during 17 days for each variable.

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Result: Experimental findings showed that in the 0.06 m3/h and 0.12 m3/h flow rate, the efficiency of bioreactor containing Pseudomonas putida in the concentration ranges of 283 Mg/m3 to 4710 Mg/m3 was at least 97% and 25% respectively. Statistical analysis (ANOVA) showed that in two flow rates of 0.06 m3/h and 0.12 m3/h removal efficiency and mineralization percentage had significant differences .(Pvalue =0.01).

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Conclusion: Achieving high efficiencies in pollutants removal was because of the prepared optimum conditions for Pseudomonas putida in the two phase partitioning stirred tank bioreactor with 10% organic phase.

Introduction: Existing literatures indicate that occupational exposure to formaldehyde may decrease blood platelets. In this study, the influences of occupational exposure to formaldehyde on the number of blood plateletsand clinical symptoms were studied while determining the occupational exposure of employees of a wood industry to formaldehyde.

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Material and Method: In a case study, the occupational exposure to formaldehyde was determined among 30 workers from production line and 30 administrative staffs of a wood company using US-NIOSH method No 2541. The number of blood platelets was determined using the normal blood count method and related indices. Demographic data as well as the clinical symptoms of exposure to formaldehyde were collected using a standard questionnaire. The smokers and those using drugs interacting with similar symptoms and blood characteristics were excluded from the study. Ethical principles for medical research involving human subjects announced in Helsinki declaration were considered. The research proposal had been approved by the university committee of ethics prior to its execution. Details of tests were explained for all subjects and a written consent was signed by each subject.

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Result: Occupational exposure of workers in various parts of particle board production line ranged from 0.5 ppm to 1.52 ppm which was higher than the ceiling level (0.3 ppm) recommended by US-ACGIH. The prevalence of all studied symptoms from formaldehyde exposure in workers was significantly higher than the administrative staffs. In case group, tearing rate was the highest average 8.98 while the chest pain with an average rate of 3.20 was the lowest. In control group, the prevalence of coughing with an average rate of 6.62 was the highest and the chest pain with an average rate of 5.53 was the lowest. The average number and standard deviation of blood platelets of workers in production line and staffs were statistically different with the range 207.33±41.79 and 254.60±71.05, respectively. The statistical tests showed no relationship between the level of occupational exposure to formaldehyde and the number of blood platelets (p>0.05). This means that, increasing the exposure level would not lead to a further reduction in the number of platelets.

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Conclusion: Occupational exposure to formaldehyde significantly changed the number of blood platelets.

Introduction: Noise exposure is known as a risk factor for hearing loss and one of its effects is noise-induced stress. Cortisol, as stress hormone- is used in noise-induced stress assessments studies. The aims of this study were:(1) measuring and comparing saliva cortisol concentrations in the morning and evening in normal work day and rest day between two groups, (2) assessing the relationship between industrial noise exposure and salivary cortisol concentrations between two groups.

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Material and Method: Two hundred male workers (100 industrial and 100 office employees) participated in this study. Morning and evening saliva samples were collected at 7 a.m and 4 p.m, respectively. Noise exposure levels were assessed by sound level meter and noise dosimeter. All measurements occurred in two days: one in rest day and other in working day. Descriptive statistics, paired and independent sample t-test and regression analysis were used as statistical tools with α=0.05.

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Result: On the rest day and work day, between morning salivary cortisol was no significant difference in two groups. Comparing evening cortisol concentrations in work day with rest day a significant difference was observed, in worker group, but it was not significant in the other group. The evening cortisol in the working day in was significantly higher among workers than officers.

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Conclusion: This study revealed that industrial noise exposure with levels higher than 80 dBA has a significant effect on salivary cortisol elevation.

Introduction: Industrial accident is one of the most minatory elements for worker’s health, productivity and organizational performance. Unsafe behavior is the main reason associated with occurrence of accidents. The main goal of this study was application of participatory techniques to achieve control measures of these behaviors.

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Material and Method: Using safety behavior sampling technique in this study, behaviors of staffs were evaluated and then the most risky behaviors were determined by paired comparison method. By application of participatory approach of dotmocracy in six steps, controlling ideas were derived by participation of operators, supervisors, engineers, HSE team and managers.

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Result: 48.8% of the behaviors were unsafe. Misuse or notusing of the personal protective equipments with 63.4% was the most frequent unsafe behavior. Awkward postures, aggregation or passing under suspended loads were also followed by the unsafe behaviors. By application of participatory approach of dotmocracy, several applicable ideas in personal protective equipment, education, reinforcementand punishment, aggregation or passing under suspended loads and other ideas were achieved.

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Conclusion: Dotmocracy participatory technique is an effective way to achieve various practical solutions in control of worker’s unsafe behaviors.

Introduction: Due to the increasing population and the need for setting in cities, we witness an increase in high-rise building in Iran. Moreover, because of the ambiguity and complexity, they have various risks potential. Health problems are among this risks for the residents. These risks have short term or long term effects,which can cause illness or even death.

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Material and Method: In the present study, health risks in high-rise buildings are identified, assessed and ranked. Health issue are identified by conducting interview with experts in high-rise building an using specific health and safety related checklists. Due to ambiguous nature of risks and existence of uncertainly, fuzzy logic technique with trapezoidal distribution was used for quantification. Finally, after risk evaluation and calculation of critical degree of each risk, the risks were ranked.

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Result: Risk factors obtained over 0.5 for most of the risks that indicate the importance of Health in high-rise projects during construction phase. The results also showed that the health risks should be assessed before the start of the project in order to reduce or eliminate their impacts.

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Conclusion: Safety risks in High-rise Building projects is very important. These risks have many impacts directly and indirectly on the time, quality and costs of projects. Therefore, evaluating and controlling each health risk in the design and implementation phases are essential. Most of the risks factors identified in this study, can be prevented by using personal protective equipment. The role of the training people involved in this projects are essential to use personal protective equipment.

Introduction: Exposure to Bioaerosols is related to a grand range of sanitation’s effects including intense poisoning effects, allergy and cancer. This study has done to determine the type and concentration Bioaerosols in the air of one of the industrial live stocks slaughterhouse in Shiraz.

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Material and Method: A total of 112 air samples from different parts of industrial live stocks slaughterhouse are collected in this cross-sectional study. According to the NIOSH method, Bioaerosols sampling was done in blood agar medium and dextro agar and by Anderson one-stage sampler with flow rate of 28.3 Lit/min, sampling duration of 10 minutes and concentration measured in CFU/m3.

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Result: According to the result, the most pollution is in blood cook place (3281.44 CFU/m3) and the least pollution exists in meat delivery place (99.1 CFU/m3 ). Also the result of the study showed that Bioaerosols concentration in industrial live stocks slaughterhouse is 28 times more than its concentration in reference site. Which is 5 km from slaughterhouse and 5 species of fungi were observe which aspergillus niger and penicillium were dominat.

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Conclusion: Bioaerosols concentration in live stocks industrial slaughterhouse is higher than the threshold limit and suggested range. Therefore, it is essential to take measures, such as improving the process and technical-engineering interventions including the use of suitable ventilation systems and also management personal monitoring measures.

Introduction: Process industries, often work with hazardous and operational chemical units with high temperature and pressure conditions, such as reactors and storage tanks. Thus, probabilities of incidence such as explosions, and fire are extremely high, The purpose of this study was to present a comprehensive and efficient method for the quantitative risk assessment of fire and explosion in the process units.

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Material and Method: The proposed method in this study is known as the QRA and includes seven steps. After determination of study objectives and perfect identification of study process, first, qualitative methods are used to screen and identify hazard points and the possible scenarios appropriate are identified and prioritized. Then, estimation of frequency rate are done using past records and statistics or Fault Tree Analysis along whit Event Tree. PAHST professional software and probit equations are used in order to consequence modeling and consequence evaluation, respectively. In the last step by combination of consequence and frequency of each scenario, individual and social risk and overall risk of process or under study unit was calculated.

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Result: Applying the proposed method showed that the jet fire, flash fire and explosion are most dangerous consequence of hydrogen generation unit. Results showed that social risk of the both fire and explosion caused by full bore rupture in Desulphrizing reactor (Scenari3), Reformer (scenario 9) and Hydrogen purification absorbers are unacceptable. All of the hydrogen generation unit fall in ARARP zone of fire individual risk (FIR) and FIR up to 160 m of boundary limit unit is unacceptable. This distance is not only beyond of hydrogen generation unit boundary limit, but also beyond of complex boundary limit. Desulphurization Reactor (75%) and Reformer (34%) had the highest role in explosion individual risk in the control room and their risks are unacceptable.

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Conclusion: Since the proposed method is applicable in all phases of process or system design, and estimates the risk of fire and explosion by a quantitative, comprehensive and mathematical-based equations approach. It can be used as an alternative method instead of qualitative and semi quantitative methods.

Introduction: In the interaction between man and machine, the human behavior plays a key role in the accidents occurrence and the risks. Safety culture models can be a base to safety culture assessments and may lead scientists toward effective aspects of organization safety. The aim of present study was to develop and offer a specific questionnaire for safety culture assessment according to the customized model in an automotive industry.

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Material and Method: In this cross-sectional analytical study, a questionnaire including 16 items and 37 questions was developed based on management, individual, and organizational factors. Then, the reliability and validity of the developed questionnaire, it were studied among 30 employees of an automotive company.

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Result: Concerning the reliability of the questionnaire, the Cronbach’s alpha was 0.855. In the context of validity of the questionnaire, the simplicity and clarification of contents were investigated by means of Expert Analysis. Moreover, in terms of the integral components of culture, according to the factorial analysis, this evaluation regarded to have ten main components.

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Conclusion: So far, there was no exclusive tool for evaluating safety culture based on a customized model. The findings of the present study showed that evaluating safety culture using the administered questionnaire is valid and reliable in the understudied industry.

Introduction: Occupational exposure to manganese can cause neurobehavioral symptoms. The aim of present study was to survey neurobehavioral symptoms of welders exposed to manganese- containing welding fumes and compare the frequency of these symptoms with unexposed group.

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Material and Method: Twenty seven of welders as exposed group, and 30 administrative workers as unexposed controls, were participated in this study. Neurobehavioral symptoms data were gathered using Q16 questionnaire. Manganese concentrations were determined according to the NIOSH 7300 method. After preparing of blood samples using microwave assisted acid digestion method, all samples were analyzed to determine manganese by graphite furnace- atomic absorption spectroscopy (GF-AAS).

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Result: The mean exposure to air manganese was 0.023± 0.012 mg/m3. Manganese concentrations in blood samples of welders (15.88± 7.11 µg/l) were significantly higher than unexposed workers (9.37± 8.70 µg/l), (P-V<0.05). The frequency of neurobehavioral symptoms of welders was significantly higher compared to unexposed workers (P-V<0.05). The correlation between neurobehavioral symptoms and blood manganese was significant for welders (P-V<0.05).

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Conclusion: Welders’ exposure to manganese and its potential health effects should be evaluated periodically and effective control measures should be applied in order to to prevent neurobehavioral symptoms.

Introduction: Manual material handling activities in long and short periods may lead to complications such as laceration, fracture, cardiovascular stress, muscle fatigue, and musculoskeletal disorders especially in the vertebrae column. The purpose of this study was to assess manual handling of oxygen cylinders by casting workers and to implement ergonomic intervention to reduce the risk of musculoskeletal disorders.

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Material and Method: This is an interventional study conducted among 18 male workers of a steel casting unit. Assessment of manual handling of oxygen cylinders, was done using in order Snook tables. The manual handling of oxygen cylinders was changed to mechanical handling and making a box with the capacity of 16 oxygen cylinders which can be moved by crane.

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Result: According to the results, lifting and lowering cylinders was not suitable for most of the workers. Moreover, caring, pulling and pushing was suitable for less than 10 percent of the workers. Condition of lifting cylinders by fire workers was suitable only 25 percent of them. According to the snook tables material handling activities must be suitable for at least 75 percent of workers.

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Conclusion: With the implementation of ergonomic intervention is casting unit, the risk of exposure to musculoskeletal disorders caused by manual handling of oxygen cylinders was eliminated and safety of employees against the risk of explosion of the cylinders in comparison with before the intervention was improved.

Introduction: In HSE management systems competency has been considered as an important tool for selecting managers and resource allocation. Lack of proper HSE managers can undermine the performance of the management system. On the other hand competent HSE managers can improve the performance of management system and reduce the time to perform activities. This study was aimed to present a model to select the HSE managers.

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Material and Method: In this study, similar models were examined to select the basic framework. Model dimensions and weights were determined using the focus group technique. The model was used in a large industrial company. The model was approved by the evaluation of the results and correction of the identified defects.

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Result: The approved model included technical, behavior and concept competence. Technical competence for managers in level 1 and 2 and behavior competence for managers in level 3, were the most important dimensions.

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Conclusion: HSE managers in various level should have different competencies which can be evaluated by presented model in the current study, before employment and also it can be used as a basis for monitoring individuals during specific period of time.

Introduction: Illumination standards especially Illumination Engineering Society of North America (IESNA) and Iran lighting standards (ILS) are just based quantitative measurements. However, lighting has psychological effects and can influence quality and quantity of productivity and comfort of workers. Therefore, Illumination standards were undergone some changes. EN 12464-1 standards focus on the quality and quantity of lighting as well as the energy consumption. The aim of this study was to evaluate quality and quantity of lighting in Shemiranat health center.

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Material and Method: In this study, first work tables were divided into 20×20 squares and illuminance was measured by putting HANGER S3 luxmeter sensor on the center of each square. In next stage, the luminance of each lighting source was measured from the view of observe and the average luminance of work table surface was calculated in the divide square. Furthermore, vertical, horizontal and lateral distance between observes eye and lighting source was measured. The gathered information was put in the equation and glare rate was calculated. Finally, according to the table we obtained color rendering index of lighting sources.

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Result: Results of this study showed that maintained illuminance dose not mach the standards (500 lux) in any of the work station. Moreover, the glare match the standards just in less than 10 percent of the work area. Therefore, it is essential to reform the artificial lighting system and keep the maintained luminance and glare at the standard level.

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Conclusion: There is a dramatic difference between the current lighting condition and the standard values. Therefore, making changes in lighting system is obviously essential.

Introduction: Following the presentation of Domino model by Heinrich in 1931 this idea was formed that human is the most important cause of accidents. According to Heinrich, unsafe behavior (88%), unsafe condition (10%) and unexpected factors (2%) are involved in accidents causation. Thus, the aim of this study was to investigates workers safety, culture and its influencing factors in detergent and cleaner company.

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Material and Method: In order to determine the level of safety culture in the understudy detergent producing company a questioner developed in 2010 was used. It was included dimensions of management commitment, training and information exchange, protective environment, inhibitory factors and priority to safety. After collecting the questionnaires, data were analyzed using SPSS version 17.

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Result: The mean age of the participants of 37.5 years old and the mean work experience 13.7 years. 52.3 % of workers had not experienced any accident during their working year. Moreover, mean (SD) score of safety culture was 180.51 (±35.216).

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Conclusion: The difference of safety culture score were statistically different among occupational groups and also between workers with and without accidents.

Introduction: In Iran country, small enterprise with less than 10 workers comprise about %90 of all industries and 80% of working population. Noise, higher than the permissible level is among the hazardous agents, workers in these plants facing with. The aim of this study was to investigate the correlation between screening estimation and noise measurement in small plants.

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Material and Method: This cross-sectional study was conducted in 51 plants with less than 5 workers. Noise screening was done using screening from. Next, noise level was measured in all the plants by TES-1358 sound level meter and regular grid method. Data were analyzed using chi-square test and linear regression in SPSS version 16.

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Result: The mean (SD) scores of sound pressure level and screening form were 86.5 dBA (4.5) and 64.2 (9.4) in 51 understudy plants, respectively. According to the results of sound measurement, sound level in 34 plants (66.6%) exceeded the permissible level and in 17 plants (33.33%) was below the limit. The results of screening forms showed that 47 plants (92.16%) had permissible level of noise while noise in 4 (7.84%) was not in permissible level. Chi square test revealed no significant relationship between the results of the two methods, based on the permissible and impermissible limits (p-Value=0.288). Furthermore, according to the regression analysis, R2 was obtained 0.357.

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Conclusion: No correlation was shown between the results of the two methods used. Thus, it is recommended to change the parameters used in the noise screening form for small plants, with less than 5 workers.

Introduction: Human and environment exposed to harmful factors, as the result of industrial pollutants. Volatile organic compounds (VOCs) play important role in photochemical reactions in troposphere layer of atmosphere and results in production of ozone and photochemical oxidants.

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Material and Method: In this study, a miniature stirred tank bioreactor was designed for treatment of waste gas containing xylene. In the next step, the bioreactor incubated with microbial consortiums with ratio of 1 to 3. The performance of bioreactor in treatment of xylene vapors in presence of 10% silicone oil, as an organic phase was assessed in concentrations ranging from 551 mg/m3 to 3330 mg/m3 for 432 hours.

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Result: The results of xylene biodegradation showed that removal efficiency up to the concentrations of 2756 mg/m3 was 82 percent. Moreover, adding 10% silicone oil increased removal efficiency of BTX by 85.7% in comparison with context without organic phase. The microbiological experiments on the bioreactor media showed that three spices of Pseudomonas putida, Chryseobacterium and Ralstonia pickettii were found, in the presence of xylene.

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Conclusion: Overall, the results of the present research revealed that application of two phase stirred tank bioreactors (TPPBs) for xylene from contaminated treatment of streams was successful.

Introduction: Introduction: Thermal comforts are one of the most human concerns in working as was as living environments in the past half century. Thermal comfort is the condition in which people are satisfied with the thermal environment, mentally. One of the new heating system employed in individual units is radiant heating system .The purpose of this study was to investigate the performance of radiant ceiling heating system and its impact on thermal comfort of workers.

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Material and Method: In the present analytical-descriptive study, the designed radiant heating systems were investigated in two repair and maintenance units, in Hamadan gas pipeline operation center. Firstly, the environment parameters, witch impact thermal comfort, were measured before and after using radiant heating system, in both understudy units. Then, wind chill index, thermal comfort indices, PMV and PPD were calculated. In addition, PPD and PMV were determined, based on workers subjective feeling by a questionnaire distributed among 22 workers.

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Results: According to the results, the radiant heating system in unit 1, has reduced the wind chill index by 42.3 Kcal/ m2.h, witch is not considered to be significant. In unit 2, wind chill index has been decreased by 109.3 Kcal/ m2.h, witch mean that thermal comfort has been changed from cold to an optimum environment. PMV n unit 1 went up by 37% after turning the system on, witch is equal to 17.24% increase in workers satisfaction. However, in unit 2, the workers satisfaction was 14.3% higher in comparison with unit 1.

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Conclusion: Due to large space of these industrial units, producing appropriate heating by convection mechanism is too difficult and expensive. The results confirmed that if radiant heating system applied based on scientific design principles they could be effective in promotion of thermal comfort due to heating surrounding surface by radiant and also reducing fuel consumption.