Journal of Health and Safety at Work

Application of dotmocracy technique in assessment and management of unsafe behaviors

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.

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.

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.

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

Noise Induce Stress Assessment via Salivary Cortisol Measuring

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.

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.

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.

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

The effect of occupational exposure to formaldehyde on blood platelets of employees in a wood industry company

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.

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.

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.

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

Study on the efficiency of the two phase partitioning stirred tank bioreactor on the toluene filtration from the airstream by Pseudomonas putida via

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.

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.

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).

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.

Room acoustic analysis of blower unit and noise control plan in the typical steel industry

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.

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.

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.

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.

The relationshipbetweenjob satisfactionwith general healthand job burnout workers inanautomotive industry

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.

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.

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.

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.

Identification and Assessment of Human Error Due to design in damagingto the Sour Water Equipment and SRP Unit of Control Room in A Refinery Plant using SHERPA Technique

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.

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.

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.

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.

Determination of HSE program proportional to organizational Corporate life cycles

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.

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.

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.

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