Journal of Health and Safety at Work

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Introduction: According to previous researches, working at the airport is one of the most vociferous jobs in the world. Airport workers are at risk of noise induced hearing loss. The present study was done to evaluate the Sound Pressure Level (SPL) in the closest aprons to Ground Safety department at Mehrabad airport and to investigate the effect of airport noise on the employees of this department.

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Material and Methods: Evaluation of SPL in the given aprons was done using sound meter and sound analyzer. Measurement stations at specific intervals to the sound source were identified inside and outside of the participants 'workplace and SPL was measured at night and day. The mean estimated values were compared with those presented by Ministry of Health. The annual participants' audiometry information was extracted from medical records. Then a self-administered questionnaire was distributed among the study sample in order to measure quality of noise exposure. The questionnaire was developed based on three general criteria including the knowledge toward the noise pollution, job satisfaction, and the exposure to the noise source and the purpose of this questionnaire was to find the relationship (correlation) between these parameters among the study population.

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Result: The measured equivalent for 8 hours noise exposure was obtained 94 dB(A) and no relation was observed between octave band sound of aircraft and recorded audiometry. Analysis of the questionnaire showed that people with more knowledge about noise pollution used more hearing protective equipment. Subsequently, by using more hearing protection equipment the level of hearing loss was reduced significantly (P<0.05). There was a significant and negative correlation between noise exposure and job satisfaction, as well (P<0.05). Also there was a significant and negative correlation between using of ear muffs and catching Noise-Induced Hearing Loss (P<0.1). The percentage of noise-induced hearing loss was calculated 51.4% among study sample.

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Conclusion: The noise exposure of employees of Ground Safety working in Mehrabad airport was higher than the permissible limit which implies the necessity for use of earmuffs and implementation of noise reduction programs.

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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).

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Introduction: Domino effects are a chain of low-probability and high-consequence accidents in which a primary event (fire or explosion) in one unit causes secondary events in adjacent units. Bayesian networks have been used to model the propagation patterns of domino effects and to estimate the probability of these effects at different levels. The unique modeling and flexible structure provided by Bayesian networks allow the analysis of domino effects through a probabilistic framework, taking synergistic effects into account.
Material and Methods: Firstly, collecting the basic information related to the location of the storage tanks and determining the scenario of the accidents were done. Furthermore, the values of the heat radiation as escalation vectors in case of a fire in one tank were determined using ALOHA software. The received heat flux values were compared with the heat radiation threshold of 15  kw/m² and the escalation probability of the primary unit and the propagation of the initial scenario to nearby storage tanks were determined using Bayesian networks.
Results: The analysis of the heat flux values showed that among the 8 studied storage tanks, two storage tanks had the highest potential for spreading domino effects due to their location in a tank farm. Also, the implementation of Bayesian networks in GeNIe revealed that, compared to other storage tanks, the probability of domino effects propagating to other nodes is higher when a primary fire accident occurs in the two mentioned tanks, while considered as primary units.
Conclusion: Domino effect modeling and appropriate preventative measures can decrease the escalation probability in the process industries. Consideration of the synergistic effects of events at different levels by taking the escalation vectors into account leads to proper risk management and the determination of emergency response measures in storage tank farms.