Iran Occupational Health
Year:2006 | Volume:3 | Issue:1-2|Papers Count:14

Background and Aims: Noise barrier is one of the most promising methods for environmental as well as industrial noise control. Basically a barrier prevents sound waves from reaching a listener in the shadow zone by the direct path. If the barrier structure is properly designed, sound can only reach the listener by other indirect ways. Based on previous knowledge on barrier methods and design's history the method and result of an investigation about the acoustic performance of noise barriers with Quadratic Residue Disfigure (QRD) top, and with Arrow-T, Y and Cylinder tops are introduced in this paper.Method: Noise barrier is one of the most promising methods for environmental as well as industrial noise control. Basically a barrier prevents sound waves from reaching a listener in the shadow zone by the direct path. If the barrier structure is properly designed, sound can only reach the listener by other indirect ways. Based on previous knowledge on barrier methods and design's history the method and result of an investigation about the acoustic performance of noise barriers with Quadratic Residue Disfigure (QRD) top, and with Arrow-T, Y and Cylinder tops are introduced in this paper.Results: The results of rigid and with absorptive coverage are also calculated for comparisons. Good agreement between the prediction results of BEM with whole surface modeling has been shown with that of the method assuming the diffuser surface as boxes with variable admittance. Using QRD on the top surface of almost all barrier models presented here is found to improve the efficiency of barriers compared with using absorptive coverage at the examined receiver positions. T-shape and Arrow-shape barriers are also found to provide better performance than other shapes of barriers. The best shape of barriers for utilising QRD among the tested models is the T-shape profile barrier.Conclusion: It is found that reducing the design frequency of QRD shifts the performance improvement towards lower frequency, and therefore the most efficient model for traffic noise is a barrier covered with a QRD tuned to around 400 Hz.

Backgrand and Aims: Paper currencies are widely exchanged for receiving goods and services throughout our country as well as rest of the world. Money bills are used everywhere and in all capacities, and are being exchanged among a lot of people during the period of their circulation. If some of these bills are infected with pathogenic bacteria, there will be a potential hazard for the well-being and health of those who handle them. Contaminated money bills are potentially very dangerous to the health of humans. The aim of this research is to specify the bacterial load of various types of collected bills from different regions in Iran. Method: This research is a descriptive, cross- sectional study. At first, 400 different paper currencies from various provinces in Iran were collected. Banknotes were put into the bottles containing sterile water and then heated for 12-24 hours at the temperature of 37°C. Afterwards, the banknotes were removed by a sterile forceps and the remaining solution was incubated. The separated microbes were identified by using microbiologic methods. Results: Data analysis revealed that 46% of different types of paper currency were contaminated with Gram positive and 54% with Gram negative bacteria. Klebsiella pneumoniae and Gram positive cocci in particular Staphylococcus aureus were the most separated bacteria, which are known as pathogens in various diseases in human body. Conclusion: These bacteria cause serious illnesses particularly in elder people, children and specifically immuno-deficient patients. We concluded that paper money in this study was contaminated. Replacement of money bills with credit/ debit cards may reduce the potential hazards substantially.

Background and Aims: Noise is one of the important injurious agents causing hearing loss or various incidents. High levels of noise pollution affect workers in stone industries. Iran has the world second rank in production of 9 million tone stone. There are 1806 stone cutting and 230 stone processing units with 6 million tones processing in the country, of them 22 stone cutting and 3.2 percent of stone processing units are located in Hamedan province.Method: In this survey 10 stone cutting units of Malayer district were chosen. Noise pollution was measured by sound level meter (model 2230 B&K). General noise using grinding method and worker posture was measured. One octave band frequency analyzing was measured in 21 stations (more than 85 dBA). Equivalent levels (leq) and Noise Induced Hearing Loss (NIHL) were calculated for 40 workers in the units. Results: Average leq was 91.1 dBA (SD: 5.5) and mean work experience was 10.9 (SD: 5.5) years). Regression analysis showed a significant correlation between NIHL and Leq (8hr) (p<0.05). NIHL and work experience was also correlated (P< 0.05). Granite stone industries octave band noise analysis had a major SPL in high frequency while other industries had low frequency. Conclusion: NIHL results in this study revealed minimal loss; however, the workers did not have long experience. A severe hearing loss in subsequent years is expected. Selection of acoustic absorbers for stone cutting units should be considered.

Background and Aims: Lead is an important environmental constituent widely used in industrial processes for production of synthetic materials and therefore can be released in the environment causing public exposure especially around the industrial residence area. For evaluation of human exposure to trace toxic metal of Pb (II), environmental and biological monitoring are essential processes, in which, preparation of such samples is one of the most time-consuming and errorprone aspects prior to analysis. The use of solid-phase extraction (SPE) has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquid-liquid extraction (LLE). The aim of this study was to investigate factors influencing sample pretreatment for trace analysis of lead in biological samples for evaluation of occupational exposure. Method :To evaluate factors influencing quantitative analysis scheme of lead, solid phase extraction using mini columns filled with XAD-4 resin was optimized with regard to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume (up to 500 ml), elution volume, amount of resins, and sample matrix interferences. Results: Lead was retained on solid sorbent and eluted followed by simple determination of analytes by using flame atomic absorption spectrometery. Obtained recoveries of the metal ion were more than 92%. The amount of the analyte detected after simultaneous pre-concentration was basically in agreement with the added amounts. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. The developed method promised to be applicable for evaluation of other metal ions present in different environmental and occupational samples as suitable results were obtained for relative standard deviation (less than 10%). Conclusion: This optimized method can be considered to be successful in simplifying sample preparation for trace residue analysis of Pb in different matrices for evaluation of occupational and environmental exposures.

Background and Aims: Work related musculoskeletal disorders are common in midwifery practice which requires extensive labor-intensive tasks. Therefore midwives are prone to musculoskeletal disorders. This study aims at investigating the risk factors and musculoskeletal symptoms among in midwives.Method: we conducted this cross-sectional study in Hamedan, western Iran. Active Midwives (n=134) were asked to complete the questionnaires (demographic and a version of the Nordic questionnaire) if they had at least 1 year experience in practice and were not pregnant during the previous year. 102 Midwives completed the questionnaires. Data were analysed by SPSS v.10 software. Results: 66.7% of the Midwives reported some musculoskeletal symptoms, of which 54% was work related. The most common musculoskeletal symptoms were low back pain (50%), shoulders and wrists (46%). There were significant associations between musculoskeletal symptoms and marital status (p< 0.001), duration of employment (p<0.02), shift work (p<0.0001), work place (p<0.002) and hours per month spent for performing tasks (p<0.01). However, there was no significant association between the symptoms and age, BMI, and the number of childbirth. 51.9% of Midwives required treatment, 33.3% missed work for seven days or more and 22.2% changed their work place.Conclusion: These findings indicate that midwives require more in-service training about their posture to reduce the prevalence of work- related symptoms and improve their overall performance.

Background and Aims: People, equipments and properties are continuously exposed to numerous hazards while technology develops. The global increasing rate of accidents and work related injuries, especially in Iran, is an evidence for these hazards. There are numerous methods for hazard analysis such as the Energy Trace & Barrier Analysis (ETBA), which is a process of analysis based on system safety for detecting and definition of hazards and also risks that may cause system damage. Method: This is a case study in the Isomax unit of Tehran refinery and allied section. Date collection and completion of the ETBA sheets were conducted through observation and interview method with experts, walking - talking through method, investigation of technical and operative documents. Results: Twelve different kinds of energy and 28 subgroups were investigated. The types of energies, existence barriers, vulnerable targets, risk assessment code, and adequacy of barriers as well as recommendations for decreasing risk level through tolerable risk were identified. Conclusion: The results of this study show potential application of ETBA in different industries, especially chemical industry, which is a method for identification hazards and prevention of work-related injuries.

Background and Aims: Background and aim: About 30-40% of lead entered the respiratory system, is absorbed to the bloodstream. Some studies have demonstrated that cigarette smoking results in blood-lead levels elevation as well as decreased blood ascorbic acid. This study has performed on this issue in lead exposed welder workers. Method: A descriptive cross-sectional study was performed to evaluate associations of smoking habit with blood lead, hemoglobin and plasma ascorbic acid levels in 32 welders. All the cases used to work in a car factory in Tehran suburb as welders 8 hours a day. They were divided into three groups based on blood lead level quartiles. The blood lead levels were determined by 8003 NAIOSH method and blood ascorbic acid level was determined by Lowery method. Results were compared (based on mean values) using independent sample t-test and analysis of variance (ANOVA) methods. Results: Results indicated that the blood lead levels in those who smoke 7+ cigarettes per day was significantly higher than those who smoke <7 cigarettes per day (p<0.05) or no smoking group (p<0.001). The hemoglobin concentrations in 7+ group was significantly lower than of the <7 (p<0.01) and no smoking (p<0.05) groups.Conclusion: Smoking habit in population, who occupationally exposed to lead, causes an increase exposure to lead and, hence, elevation of blood-lead levels as well as inhibition of hemoglobin synthesis and therefore reduces hemoglobin concentration.

Background and Aims: Air pollution in the occupational health field is studied from different viewpoints such as health effects, products quality, equipments damages, and environment preservation. Furturemore, nowadays, deep attention has been merely turned toward air pollution control in the shade of economical aspects and air pollution control projects carried out in accordance to cost- benefit analysis.Method: This project was carried out in two press workshops in a tile factory. Airborne dust concentrations were measured and evaluated, using NIOSH 0500 method. Then, in order to determine the cost of press workshops dust, four stages were performed as following: 1. Impact of dust on quality of product tiles by using of the standards developed by the Industrial Research Institute (No. of 4006, changing them from grade one to grade two). 2. Annual cost of production disruption (turning off machines for dust cleansing) 3. Annual cost of dust control device (bag house) 4. Annual cost of house keeping in two press workshop. Finally, results were evaluated by using of the cost- benefit analysis equation. Results: According to the results obtained from this study, concentration of dust in production workshop 1 were higher than workshop 2 (59.262 mg/m3 and 32.158 mg/m3 respectively).Also results showed that, the average of 8.4% from total tile production has changed to grade two, costing 1000 million Rials. Annual estimation for appropriate dust control device based on advised equations (EPAData Sheets) in each workshop was 277,322,578 Rials. There was a yearly production disruption cost of 1375.98 million Rials in the workshop 1 and 564.2 million Rials in workshop 2. There was also 10.88 million Rials cost for house keeping yearly. Conclusion :On the basis of the results obtained from cost-benefit equation (in a period of 20 years) it was revealed that, there is a benefit equal to 7.72 billion Rials in press workshop 1 and 3.31 billion Rials in press workshop 2 (11000 million Rials totally), if employer performs air pollution control project. Finally, according to the results obtained from this study, application of dust control project in two study areas was beneficial and the results are also promising to generalize the viewpoint over the all across the different industries. 

Background and Aims: This study was hold in purpose of recognizing and controlling workplace hazards in production units of a drag Manufacture.Method: So for recognition and assessment of hazards, FMEA Method was used. FMEA Systematically investigates the effects of equipment and system failures leading often to equipment design improvements. At first the level of the study defined as system. Then according to observations, accident statistic, and interview with managers, supervisory, and workers high risk system were determiner. So the boundaries of the system established and information regarding the relevant Components, their function and interactions gathered. To prevent Confusion between Similar pieces of equipment, a unique system identifier developed. After that all failure modes and their causes for each equipment or system listed, the immediate effects of each failure mode and interactive effect on other equipment or system was described too. Risk priority number was determined according to global and local criteria.Results: After all some actions and solution proposed to reduce the likelihood and severity of failures and raise their delectability. Conclusion: This study illustrated that although of the first step drug manufacture may seem safe, but there are still many hazardous condition that could cause serious accidents, The result proposed it is necessary: (1) to develop comprehensive manual for periodical and regular inspection of instruments of workplaces in purpose of recognize unknown failures and their causes, (2) develop a comprehensive program for systems maintenance and repair, and (3) conduct worker training.

Background and Aims: Silicosis is a diffuse interstitial fibronodoular lung disease caused by inhalation of dust containing free crystalline silica. Crystalline silica can cause several forms of silicosis. Silicosis is still a significant health problem around the world and it remains a common and disabling lung disease in developing nations.Exposure to silica occurs by inhalation of dry mineral particles of reparable size (0.2 to 10?m aerodynamic diameter.Method: By a cross-sectional study 100 male workers in silica production factories were surveyed. Information on health status of workers was gathered with questionnaire, Spiro meter and chest x-ray. Results: The results illustrated 21 workers with signs and symptoms and abnormal physical examination. Persons had significant abnormal sign evidence in their chest x-ray, and 14 workers had abnormal Spiro gram patterns.Conclusion: The result also indicated that 10 workers had overt silicosis and 11 workers can come back and start working, provided that improvement workplace and control of silica dust. This study showed a significant association between Dose-response silica exposure and the incidence of silicosis.

Background and Aims: Considering population growth and resource limitation in agriculture field and essential requirement to increase agriculture products, importance of logical against pests is obvious. These programs must consider farmers, community and environment health. There are many way to combat against pests, and chemical poisons are the most method that is used.Human exposure occurs in different way during use of pesticide and their residual in environment. Pesticide don't act selectively, this means that they have effect on not subject (e.g. human) as like as they have effect on pests.According to Iran statistic center, 25.9% of economical efforts, and 26% of worker with age more than 10 year in this country are.Method: The amount of sailed pesticide has reached to 27.2 thousand tons. In this research 50% of samples (farmer) were illiterate, and their average work experience was between 18 and 26 year. In different area according to kind of product and effectiveness specific poisons was used. Results: For example in Rafsnajan and Savojbolagh, more than 25% of used pesticide were organophosphores. Also 68% of farmers did not use any personal protective equipment. Just 25% of farmers said that can understand printed in formation on pesticide tables 55% of farmers left vessel of pesticides in environment and just 27% of them burned or landfill the vessels.Conclusion: According to these result, we recommend to make a educational package consist of pesticide and their uses, the way of management their short and long term effects, the way of effective use of personal protective equipments, and the necessary act after use of vessel. This should be done under sight of special units and experts. This package must be in Farsi language, easy to understand, and if possible in local language. Employer and managers have to give personal protective equipment to farmers and aware farmers about emergency act and give them education regarding burning and landfill poison's vessels in a suitable hygienic way.