Journal of Health and Safety at Work

Evaluation of sound propagation inside the cabin and outside the agriculture machinery of sugarcane industry in both mobile and stationary state

Introduction: Agriculture is one of the oldest jobs in the world and almost 7-2 billion people all over the world are working in this field. In the field of agriculture workers may be always in danger, due exposure to various chemical and physical factors. Despite the dramatic technological developments in agricultural science, this field is still among one of the most dangerous workplaces in the world.

Material and Method: This study is conducted in the suger cone industry. It is about agricultural machines and their major role in noise production. In order to identify the dominant- source index model was proposed.

Result: All the agricultural machines were classified and the main characteristics of each group such as type of the machines, their number, the number of operators, and existence of cabin, were determined. Also operator's annual exposure to noise was measured according to the international standards. The data was analyzed with the proposed model formula, and the noise – source indices were calculated.

Conclusion: The results show that the suger cane reaper poster case I H7000 has the highest noise- production index among all other agricultural equipments. So the suger cane reaper was identified as the main source of sound production in the agricultural industry. This machine in usually being used in harvesting the suger can farms. After identifying this device as the main source of sound in the suger can farming industry, a sound – controlling method was proposed in order to reduce the operator exposure in the caloin. First a fall, the noise frequently of the inside and outside of the cabin was analyzed in case the engine speed was 2100 rpm. After identifying the dominant frequency, the capacity of cabin sound reduction was determined with the usage of cabin transferring reduction index the proposed control method was based on increasing the absorption of the cabin. The results shows that the Sound pressure level indices in the dominant frequencies of 125, 250, 500, 1000, 1000.2, 90.3 were respectively 100.2,90.3, 86.6,83.6 but after performing the control method the numbers were reduced to 82.1,75.2,80.5,80.2 in the other hand. Sound pressure level in frequencies of 8000, 4000, 2000 was below the permutable limit and does not cause significant dangers. So there will be no need for further reduction in noise levels.

Health, Safety and Environmental Risk Assessment in Laboratory Sites

Introduction: ”Exposing to danger” or in other words, “risk” is a process which is led to an uncertain result in every field. Project risks are uncertain contingent events or situations that if they occur will have positive or negative effects on project’s objectives. Todays, research and educational process and more complicated and the professional risk management become much more difficult, as a result.

Material and Method: In this research, the health and safety issues have been studied and analyzed using ISO 14121 and the environmental issues by EMEA to determine the risk level separately for research laboratories and to prioritize corrective measure in each field (school).

Result: The finding in this study showed that from all the main risks within the rage of 38-86 percent have been decreased. Moreover average of the risk level for the health, safety and environment cases showed a significant decrease (Pvalue<0.0001) by implement controlling and protective countermeasures compariy to the priority state without any measures.

Conclusion: The risk assessment with hazards control strategy based on ISO 14121 is a compatible method in laboratory site as universities and other reasearch sites.

The prevalence of musculoskeletal disorders and occupational risk factors in Kashan SAIPA automobile industry workers by key indicator method (KIM), 1390

Introduction: work related musculoskeletal disorders are the most wide spread type of occupational diseases among workers. Awkward body postures during work and manual material handling are among the most important risk factors of musculoskeletal disorders in different jobs. Due to importance of recognizing these factors prevalence and risk factor of work related musculoskeletal disorders, this research was aimed to study the among employees of Kashan City’s Saipa automobile industry in 2011.

Material and Method: This study is a descriptive-cross sectional study conducted among workers with manual material handling 37 activities and 84 work duties. To recognize musculoskeletal disorders, body map questionnaire was applied and occupational risk factors were evaluated using Key Index Method (KIM). Data was analyzed using SPSS and Excel software.

Result: Highest prevalence of musculoskeletal disorders was in low and upper back region (%92). Based on the results from KIM, workers in the installing the tire, shuttle-aided fitting of seat, and engine work station had higher risk level with the scores of 66, 52 and 52, respectively. Risk level among three individuals (%3.6) was at 1, 40 (%47.6) at 2, 38 (%45.2) risk level 3, and 3 (%3.6) at 4.

Conclusion: Awkward body posture, improper twisting and flexion of low back were major risk factor among worker doing manual material handling tasks. Regarding the high prevalence of musculoskeletal disorders, appropriate ergonomic interventions such as engineering and organization interactions can reduce this risk factors (posture, heavy load, duration, workplace conditions) as much as the risk level reach to an acceptable level.

Evaluation of Photo ionization detector performance in experimental studies of chemical agents in the workplace

Introduction: Nowadays, in many different fields of chemical agents several experimental researches is being done on volatile organic compounds using gas chromatography, which is time consuming and expensive methods. Photo ionization detector as an alternative method is used by researchers in this field. This feasibility study was conducted to replace the photo ionization detector with gas chromatography.

Material and Method: In this study, after making pre-determined concentrations of Xylene, the results of measurements using photo ionization detector and reference method were compared. This comparison was done in 4 humidity levels and 3 concentration ranges.

Result: The results showed significant differences in photo ionization detector readout and the reference method. However correlation coefficient of two methods were more than 0.99 in all cases regardless of the humidity rate.

Conclusion: Although the results obtained by the photo ionization detector are different from those extracted from the reference method in the current study, due to linear response of the method correlation coefficient was at good level. Consequently, in case of studying concentration changes in a research, this alternative method would be applicable, otherwise calibration of the photo ionization detector with the target material is recommended.

Photocatalytic Oxidation of Methyl Ethyl Ketone in a Fluidized Bed Reactor

Introduction: Emission of volatile organic compounds through industrial processes to the environment has been received more attentions currently. Photocatalytic oxidation process as a new emerging technique in air purification can be substituted for conventional techniques such as activated carbon adsorption. In photocatalytic oxidation process, pollutant molecules decompose to water and carbon dioxide molecules. The objective of present study was the examination of influencing parameters such as concentration, relative humidity, and superficial gas velocity on photocatalytic oxidation of Methyl Ethyl Ketone (MEK) in a fluidized bed reactor.

Material and Method: In this study photocatalytic oxidation of MEK was examined in a fluidized bed reactor. Gamma alumina coated titanium dioxide particles under ultraviolet light were used as photocatalyst. The efficiency of photocatalytic oxidation process was determined using measurement of MEK concentrations at the inlet and outlet of the fluidized bed reactor.

Result: The study of MEKphotocatalytic oxidation was carried out in the concentration range of 100 to 800 PPM with 25% and 45% relative humidity. Photocatalytic degradation of MEK at the relative 45 % humidity was slightly lower than 25 %. Increasing MEK concentration from 200 to 800 PPM was led to decrease in degradation efficiency. At concentrations of 100 and 200 PPM MEK, increasing superficial gas velocity did not change the degradation efficiency, whereas, at concentrations of 200 to 800 PPM, increasing superficial gas velocity resulted in decrease in MEK degradation.

Conclusion: In photocatalytic oxidation of MEK, there is a competitive adsorption between water and MEK and at higher relative humidity degradation of MEK decreases. In the fluidized bed reactor increasing superficial gas velocity causes decrement in MEK photocatalytic degradation.Increasinginitial concentration of pollutant results in decreasing ofphotocatalytic efficiency due to the limited number of active sites on the catalyst surface.

Study of nurses’ knowledge on low back pain risk factors in Hospitals of Shiraz University of Medical Sciences

Introduction: Low back pain (LBP) is a common and costly health problem. It has high prevalence in nursing job and caused shortage of nursing staff. This study was conducted to determine the prevalence of LBP, knowledge level of LBP risk factors and assess relationship between LBP prevalence and nurses’ knowledge level of LBP risk factors among nurses of Shiraz University of Medical Sciences (SUMS).

Material and Method: In this cross-sectional study, 118 randomly selected registered nurses participated from SUMS hospitals with at least one year of job tenure. In order to assess nurses’ knowledge of LBP risk factors, a self-administered survey questionnaire consisted of four parts was used as data collecting tool. Statistical analyses were performed using SPSS (version 11.5). Duncan, T-test and ANOVA tests were used for data analysis.

Result: LBP prevalence rate was found to be 79.7% (94 nurses) during the previous year from which 12 nurses were male (63.2%) and 82 nurses were female (82.8%). Nurses’ knowledge level of LBP risk factors in different hospitals was not significantly different. The Results showed that nearly half of the nurses had poor knowledge about LBP risk factors and the remaining had good knowledge level. The main source of information about LBP risk factors among nurses were related to their university education.

Conclusion: A high prevalence of the LBP was found among nurses working at SUMS hospital. Knowledge level of nurses about LBP risk factors needs improvement. In addition to university education, which is the main source of information of nurses about LBP risk factors, on-the-job training seems essential in this field.

Safety level assessment in the production environment using Fuzzy logic

Introduction: In addition to direct and indirect costs of occupational accidents imposing on production companies, they impact the productivity of labor, too. However, gaining more profits and having less costs is always the main concern among industrial managers. Considering safety measures can be effective way to reduce occupational accidents and costs as well as negative impacts on production systems.

Material and Method: In this paper, a risk assessment method using fuzzy and MATLAB software is presented to determine the safety level of production environments. The main parameters of this model include three items: accident probability, accident severity and current safety level. For this purpose, the statistical data of accidents and their causes published by Social Insurance Organization have been used in this study. Furthermore, expert judgments of safety and health professional have been used to determine the severity of accidents. In the fuzzy method, the Mamdani deductive fuzzy model has been adapted due to its easy applicability. Application of the model has been shown using a practical instance.

Result: The defuzzified value for RL is found to be 3.48. Linguistic risk level expression is 100% substantial high risk that is full membership for fuzzy average set.

Conclusion: The application of the proposed method can reveal which safety items and factors are most important in improving workers safety, and therefore decide where to concentrate resources in order to improve the safety of the work environment.

Prioritizing of Noise Control Methods in the Hamadan Glass Company by the Analytical Hierarchy Process (AHP)

Introduction: The purpose of this study was prioritizing the noise control methods using Analytic Hierarchy Process (AHP) technique in Hamadan glass industry.

Material and Method: This is a cross-sectional – descriptive - analytical study. According to a survey of experts by questionnaire and Delphi method four criteria were selected including cost, efficiency, executive capability and not to interfere in the process and eleven alternatives for control options. Prioritizing of the items was conducted based on the study criteria as well as the importance ranking determined in this study.

Result: The results showed all that consistently Ratios were less than 10 % and compatibility of answers has been confirmed. According to expert’s views, the criteria of executive capability (0.277) and using the barrier between the two main sections (0.111) have achieved the highest priority among the criteria and control methods, respectively.

Conclusion: In this study a pattern of decision-making structure was introduced based on Analytic Hierarchy Process for determining the method noise control. This method can improve the decision making process and prioritizing noise control methods as an efficient and effective approach.