Journal of Health and Safety at Work

Introduction: In the process industries, especially industries with hydrocarbons uses, due to flammability and reactivity of materials, high temperature, operation pressure, volatility and evaporability of liquid, fire and explosion hazard always has a great significances.The purpose of this study was to assess the quantitative fire safety using DOW’s fire and explosion index, in an oil extraction industry.

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Material and Method: The required information for conducting this research was obtained from process documents, DOW’s fire and explosion guideline,the measured operational parameters and also interviews and consultation with the supervisors and experts. Following, the study was conducted in three phases: 1) determination of DOW index, the radius and area of contact, 2) determination of loss control credit factor and finally 3) loss estimation.

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Result: Fire and explosion index in the understudy process unit was calculated 243.68 and thus severity of risk was extremely high and unacceptable. Radius of exposure and loss control credit factor wasobtained62.38 meters and 0.69, respectively. Finally,the most probable loss was estimated about 2863500 dollars.

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Conclusion: DOW’s fire and explosion index is a suitable technique to measure the fire risk of whole plant or a part of it. Thus, this criterion can be used to propose the changes or amount of protective equipment according to their effect in reducing the losses.

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.

Introduction: Heat is one of the hazardous physical agents in the workplace. Exposure to heat and consequent thermal stress influence workers productivity in addition to adverse health effects. The aim of this study was to determine the heat stress induced productivity loss related to different tasks of farmers in Darreh Shahr city, during summer.

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Material and Method: This cross-sectional study was conducted in summer, 2014, among farmers in Darreh Shahr city. After determining the sample size, farmers’ activities were determined using hierarchical task analysis (HTA), and WBGT measurements were done according to the ISO7243. Metabolism was estimated by the ISO8996. Following, the type of activities were identified according their required metabolism. Knowing WBGT and workload and using the work capacity model, the productivity loss in different tasks and ultimately total productivity loss were calculated.

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Result: The mean WBGT activities for plowing, terracing, planting seeds, watering, fertilizing, weeding, spraying, and harvesting were 29.98 °C, 31.28 °C,30.66 °C,31.39 °C,31.99 °C,31.75 °C,31.08 °C, and 30.3 °C, respectively. WBGT values were higher than the permissible level provided by ISO7243 in all farming activities. Maximum value of WBGT was belonged to fertilizing activity (31.99 °C) and the lowest value was for plowing (29.98 °C). ANOVA test results did not show a significant difference in WBGT at head, waist, and ankle height. The highest and lowest amount of productivity loss was estimated respectively for weeding and plowing activities. The total productivity loss for farming was calculated 69.3 percent in an hour which is due to high physical activity, working outdoor, with exposure to direct solar radiation, and consequent heat stress imposed to workers.

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Conclusion: Productivity is a factor which is affected by the workplace heat stress. According to results of the present research, the amount of productivity is reduced in different tasks due to heat and this reduction is exacerbated by increase in temperature and might impact the local economy. Thus, further studies are needed to improve the working conditions.

Introduction: One of the important consequences of globalization and development, especially in developing countries, are occupational accidents. As, today the economic burden due to these accidents is remarkable on the country’s economy. The aim of this study was financial estimate of the productivity loss due to work-related deaths in Iran in 2013.

Material and Method: In this study, occupational accident data were used registered in the environmental and occupational health center, in Iranian Ministry of Health and Medical Education. A formula used by the Centers for Disease Control and Prevention America (CDC) was used to estimate the productivity loss. Finally, after replacing the necessary parameters amount of productivity loss was calculated.

Result: The total lost years of life were calculated 1293.15 years due to the deaths caused by occupational accidents. The total amount of monetary loss due to the productivity loss in the country, was estimated 730513.06 Rials. The greatest loss was in the 59-50 years old age group.

Conclusion: The negative rate of productivity, the large quantity of the discount rate, low life expectancy in the country as well as the low wages of the workers, are the likely reasons for minimal negative impact of the workforce deaths on the country’s productivity.

Introduction: The use of hearing protective devices (HPDs) is the last way for noise control. It is important to know the information about the duration time using these devices to ensure protetion effectiveness. The aim of this study was to investigate the effect of increasing duration time of the using of the devices on hearing loss in tile industry workers with application of the BASNEF education model.  

Material and Method: Task Base Method (TBM) and ISO9612(2009) standard methods through a noise dosimeter device were used to exmine workers’ noise exposure level when they didn’t used of HPDs. Actual performance of HPDs was determined by using the NIOSH standard before and after training intervention and measuring time of use and protection device type. Data were analyzed using SPSSVv19 and conducting t-test and ANCOVA statistical tests.   

Result: Before training intervention, the actual noise level for case workers was 89.76 dBA. On the contrary, this value was 84.04 dBA for after intervention, with a significant difference with control group (P<0.0001) using ANCOVA analysis. In control group, the actual level of noise has not changed because this group has not received any training.

Conclusion: The results revealed that, based on BASNEF education model, duration time of using hearing protection devices is effective on increasing their function and performance.