28 research outputs found
Anthropogenic factors and spatio-temporal conditions affecting occupational accidents in fishery sector, Iran (2007- 2011)
The high occupational accident rate in fishery sector is a worldwide issue. The aim of present study was to investigate the characteristics of occupational accident in fishery sector of Iran during 2007- 2011. In the present study, a total of 1076 fishery occupational accidents being recorded during 2007- 2011 by the Ministry of Labor and Social Affair were invetigated. A Chi-square test was used to investigate the association between factors influencing accidents. The most victims aged less than 35 years old (45.47%), with elementary and secondary educations (64.58%), married (75.84%) and based in south of Iran (46.1%). The most accidents occurred on summer (27.23%), during 8-12 hours of day (32.78%) and among workers with less than 1 year experience (44.89%). Significant associations were found between accident time (season), educational levels of victims, age of victims, geographical location and victim’s experience with accident occurrence. The accident control programs, especially related occupational accidents, identifying groups at risk and factors' affecting the accidents were the crucial issues to be identified. There are some possible management actions that most likely would reduce occupational accident rate in fishery sector including: raising safety awareness, encouraging workers to participate in safety programs, encouraging workers to use protective equipment during fishery
Improvement of electromagnetic shielding effectiveness for radar frequencies (X-band) using dispersion factor
Background and aims: X-band with 8-12.5 frequencies range has various applications such as air control traffic, navy communication etc. Uncontrolled exposure with microwave can lead to adverse effect on workers. Currently, application of the shielding is a superior control for prevention of microwave exposure. This study investigated the effect of dispersion on shielding effectiveness improvement about a novel nanocomposit shiled. Methods: Nanocomposites prepared by epoxy resin and nano nickel oxide (7wt) with 2, 4 and 6 mm thicknesses. In order to investigate the effect of dispersion, 10 and 66 minutes was considered as mixing time. Nanoparticles characterized by X-ray Diffraction and Field Emission Scanning Electron Microscope. Shielding effectiveness measured with vector network analyzer. Results: Dispersion of nanoparticles in group 2-nanocomposites was better than group 1-nanocomposites. Average of percentage attenuation in group 2-nanocomposites was better than group 1- nanocomposites. The Average of shielding effectiveness for three thicknesses in group 1 was 46.5, 69.03, 70.83 and for group 2 was 52.02, 78.48 and 84.14dB, respectively. Maximum attenuation obtained by the 6mm thickness in group 2- nanocomposites at 8.8 GHz frequency (91.12). The Average of shielding effectiveness increased with increasing the thickness. Conclusion: With increasing the mixing time, the dispersion and shielding effectiveness be improved. These nanocomposites could be used as appropriate shielding for exposure control of X-band frequency in workplace and nanocomposite with 4mm thickness is appropriate shield in this study. Both 4mm and 6mm thicknesses in group 2 are useful in specific frequency such as 8.8 and 12.5 GHz.the average of percentage attenuation for above thicknesses is more than 87. © 2016; MA Healthcare Ltd. All rights reserved
Changes in body mass index and lipid profile in psoriatic patients after treatment with standard protocol of infliximab
Psoriasis is a chronic and inflammatory dermatologic disease. Psoriasis may predispose to cardiovascular disease and diabetes. However, the role of tumor necrosis factor (TNF) inhibitor in mediating this risk is controversial. Regarding frequent use of infliximab in psoriasis, and the hypothesis that anti TNF-α treatment may increase Body Mass Index (BMI) and alter lipid profile in these patients, the aim of this study was to assess changes in BMI and Lipid Profile and level of leptin in Psoriatic Patients under Treatment of Standard Protocol of Infliximab in a 24 week period. This study was accomplished as a before-after study. Twenty-seven psoriatic patients were included, and standard infliximab therapy was applied. All patients underwent 3 times of blood collection and in each session; LDL, HDL, Total Cholesterol, Triglycerides, Leptin, and PASI score were measured at the start of the study and at the 12th and 24th week of follow-up. Twenty-five patients consisted of 18 (72) male and 7 (28) female subjects were evaluated. The mean age of the patients was 36.91±13.31 years. PASI score demonstrated significant decrease after 24 weeks; however, BMI and HDL and leptin showed a significant increase during treatment. Significant negative correlation was seen between Leptin and PASI score changes (r=0.331, P=0.042). HDL and BMI had the most correlations with leptin (positive correlation) and PASI score (negative correlation). Results demonstrated a dramatic decrease in PASI, increase in BMI and HDL and increased in leptin; somewhat correlated to each other. These results suggest that patients taking infliximab should take more care of their weight and lipid profile, while on treatment. © 2016 Tehran University of Medical Sciences. All rights reserved
Assessment of outer hair cell function and blood antioxidant status of rabbits exposed to noise and metal welding fumes
Objectives: To investigate the interaction between welding fumes and noise in causation of hearing impairment. Methods: Groups of rabbits (n = 6) were exposed to noise, welding fumes or combination of both prior to Distortion Product Otoacoustic-Emissions (DPOAEs) analysis. The function of outer hair cells (OHCs) was examined by DPOAE assessment over a broad range of frequencies. Variations in DPOAE amplitude were compared between control (n = 6) and exposed (n = 18) groups. Results: The DPOAEs levels measured at different frequencies (1379-6299 Hz) were found to decrease significantly (P < 0.05) in rabbits exposed to 110 dB sound pressure level (SPL) broadband noise (8 h/day, 12 days). In rabbits, exposed to carbon-steel welding fumes alone (157 mg/m3), the threshold shift was limited to the high frequencies (2759-6299 Hz), whereas, mixed exposure to noise and fumes resulted in reduction of DPOAEs at all the frequencies. Changes in DPOAEs were associated with increased susceptibility of erythrocytes to oxidation (P < 0.05). Exposure to noise or fumes alone or simultaneously, suppressed total antioxidant ability of plasma as measured by ferric reducing ability of plasma (FRAP). Noise alone or in combination with fumes resulted in depletion of blood glutathione (GSH). Despite suppression of FRAP in the exposed groups, GSH was found to remain unchanged due to welding fumes suggesting that antioxidants other than GSH are affected by toxicants present in metal welding fumes. Conclusion: Exposure to very high levels of welding fumes can increase noise-related effects on OHC function by extending hearing threshold shift to wide band frequencies. © 2006 Elsevier Ireland Ltd. All rights reserved
The role of a new electromagnetic shielding in reducing the microwave radiation for the X-band frequencies
Background and aims: X-band microwave with 8-12.5 frequency range has various applications such as air control traffic, navy communication etc. Uncontrolled exposure with microwave can lead to adverse effect on workers. Application of the shielding is superior control for prevention of microwave exposure. The aim of this study is production a new electromagnetic shielding for exposure control of X-band frequency by nano nickel oxide and epoxy resin. Methods: Nanocomposites prepared by epoxy resin and nano nickel oxide (7 wt) with 2, 4 and 6 mm thicknesses. Nanoparticles characterized by XRD and FESEM. Shielding effectiveness measured with vector network analyzer. Results: The Average of shielding effectiveness for three thicknesses were 2.68, 5.09 and 5.35 dB respectively that were equivalent to 45.98, 69.01 and 70.87 attenuation percentage. Maximum attenuation (8.96 dB or 87.29 attenuation percentage) obtained by the nanocomposite with 6mm thickness at 8.51 GHz frequency. The Average of shielding effectiveness increased with increasing the thickness. Conclusion: these nanocomposites could be used as appropriate shielding for exposure control of X-band frequency in workplace.Both Epoxy and nanocomposite with 6mm thicknesses are useful in specific frequency such as 8.52 and 8.51 GHz. However, According to economical and technical issues, nanocomposite with 4mm thickness is appropriate shield in this study. In according to required attenuation and economical benefit, attenuation matrix can be used for selecting the appropriate electromagnetic shield
Evaluation of chlorine dispersion from storage unit in a petrochemical complex to providing an emergency response program
Background and aims Chlorine gas is a dangerous material that is used in chemical industries. In spite of the attempts for chlorine gas release control, sudden releases still occur in the related installations. Not taking proper emergency measures after chlorine gas dispersion may result in serious harm to health of the personnel and the people residing around the industrial area. The present study considers chlorine gas dispersion scenarios, determines emergency levels and presents an optimized pattern for more effective and faster response with the least required measures for emergency conditions control. Methods In the present paper by using Hazard and Operability Study (HAZOP) and risk matrix the possible scenarios of chlorine gas dispersion in storage tanks unit of a petrochemical complex were considered. Then the intervals of these scenarios were determined with a view to Emergency Response Planning Guideline 1-2-3. With a view to the intensity of pollution extension and the population exposed to risk the scenarios were classified in the four emergency levels defined by Center for Chemical Process Safety (CCPS). Finally for each class of scenarios with a view to the related emergency level an optimum pattern of response plan in emergency conditions was presented. Results On the basis of the results of this study, chlorine gas dispersion scenario of the catastrophic explosion of the tank and scrubber system failure in the summer was classified in emergency level 4, in the winter in emergency level 3, chlorine gas dispersion due to chlorine lines rupture in the summer and winter in emergency level 3 and chlorine gas dispersion due to leakage of flanges and gaskets in emergency level 2 according to emergency levels of CCPS. Conclusion The results of this study showed that systematic process risks analysis by use of risks recognition methods such as HAZOP and consequence analysis may have an effective role in recognition of the possible major events. Also by classification of release scenarios in CCPS emergency levels, we can select the best pattern for emergency conditions management
The relationship between safety climate factors and workers behavior working in potentially dangerous situations in height among construction workers
Background and Aims Falling from height is considered one of the most important risks in construction sites and many workers through non-compliance with safety tips lose their lives. This study was conducted in order to survey the relationship between safety climate factors and behavior of workers working in potentially dangerous situations in height among construction workers . Methods For evaluation of safety climate factors a safety climate questionnaire and for behavior of workers in potentially dangerous situations behavioral questionnaire including potentially dangerous situations, work on ladders and scaffolding has been used. Factor analysis to analyze safety climate factors and Binary logistic regression using SPSS software for the influence of factors on behaviors in potentially dangerous situations are used. Results Factors of safety attitudes of workers, the level of risk in construction site and working relationships derived from factor analysis are 57% of the total variance. Situations of working on scaffold without Guard rail and protect the edges, access to the scaffold by going up and down connections and the ladder not secure are usually seen in the most construction sites. ConclusionResults indicate that workers have awareness of work in dangerous situations but perhaps management ignorance of safety issues and not doing engineering controls to eliminate potentially dangerous situations can be mentioned as the causes of accidents as may result safety issues to be ignored by construction workers working in dangerous situations.
A new microwave shield preparation for super high frequency range: Oc-cupational approach to radiation protection
Background: Widespread use of X-band frequency (a part of the super high frequency microwave) in the various workplaces would contribute to occupational exposure with potential of adverse health effects. According to limited study on microwave shielding for the workplace, this study tried to pre-pare a new microwave shielding for this purpose. Methods: We used EI-403 epoxy thermosetting resin as a matrix and nickel oxide nanoparticle with the diameter of 15-35 nm as filler. The Epoxy/ Nickel oxide composites with 5, 7, 9 and 11 wt were made in three different thicknesses (2, 4 and 6 mm). According to transmission / reflection method, shielding effectiveness (SE) in the X-band frequency range (8-12.5 GHz) was measured by scattering parameters directly given by the 2-port Vector Network Analyzer. The fabricated composites charac-terized by X-ray Diffraction and Field Emission Scanning Electron Microscope. Results: The best average of shielding effectiveness in each thickness of fabricated composites ob-tained by 11-2 mm, 7-4 mm and 7-6 mm composites with SE values of 46.80, 66.72 and 64.52, respectively. In addition, the 11-6 mm, 5-6 mm and 11-4 mm-fabricated composites were able to attenuate extremely the incident microwave energy at 8.01, 8.51 and 8.53 GHz by SE of 84.14, 83.57 and 81.30, respectively. Conclusions: The 7-4mm composite could be introduced as a suitable alternative microwave shield in radiation protection topics in order to its proper SE and other preferable properties such as low cost and weight, resistance to corrosion etc. It is necessary to develop and investigate the efficacy of the fabricated composites in the fields by future studies. © 2016, Health Hamadan University of Medical Sciences. All rights reserved
Combined application of wet-bulb globe temperature and heart rate under hot climatic conditions: a guide to better estimation of the heat strain
Background: Working under hot climatic conditions, especially in summer, has a high potential for inducing heat strain in workers. The wet-bulb globe temperature (WBGT) index has an inherent limitation to estimate the heat strain due to not taking into account the non-environmental factors. The aim of this study was to evaluate the combined application of WBGT index and a physiological strain index (PSIHR) based on heart rate in the estimation of the heat strain under hot climatic conditions.Materials and Methods: This cross-sectional study was conducted on 122 men in the center and south of Iran (51 and 71 workers from Isfahan steel company and Assaluyeh national petrochemical company, respectively) between July and September 2010. The WBGT index, heart rate and the auditory canal temperature were measured at rest and during the work. Data were analyzed using descriptive statistics and logistic regression.Results: Results of the logistic regression analysis revealed that the WBGT index is a poor predictor for heat strain with a sensitivity and specificity of 53 and 65, respectively. However, the combined application of the WBGT and PSIHR indexes was a better predictor for heat strain and its sensitivity and specificity were 75 and 69, respectively. Conclusion: A combined application of the WBGT and PSIHR indexes can be a valid estimator of heat strain for hot climatic conditions in the center and south of Iran
Examination of the optimized conditions for the conversion of NO X pollution in DBD plasma reactor
Since NOx family, one of the most important causes of air pollution, is the primary source of acid rains, ozone layer depletion, and breathing disorders, mitigation of these pollutants is now a global concern. In the off-gases of internal combustion engines running with oxygen excess, non-thermal plasmas (NTPs) have an oxidative potential, which results in an effective conversion of NO to NO2. This paper aims at studying the methods of mitigating and eliminating NOx in an atmospheric and non-thermal condition by means of plasma reactors. It examines some key parameters such as temperature, space velocity, voltage, and propane/NO x mole ratio. The results showed that, the space velocity in the 11500-2300 h-1 domain did not show any significant results on the NOx conversion. Our findings also revealed that the optimal conditions for conversion of NO into N2, O2, and NO 2 are temperature (180 °C), voltage (10 kV), and equal mole ratio of propane in NOx. In this condition, the optimal conversion efficiency of 78 and the standard deviation of 12 were obtained. The optimal temperature, voltage, and the mole ratio of propane in NOx conversion to N2 and O2. (efficiency=53) are 180°C, 5 kV, and 0.3 respectively. Plasma reactor acts as primery treatment in the direct mitigation of NOx into neutral and non-poisonous molecules of O 2 and N2