Showing 5 results for Bacteria
M. Jahangiri, M. Neghab, R. Rostami, M. Aghabeigi, V. Kahdemain, F. Zare Derisi,
Volume 3, Issue 4 (2-2014)
Abstract
Introduction: Bioaeroslos released from wastewater treatment plants may contain pathogens existing in the sewage which could endanger the health of workers. The aim of this study was to evaluate the status of bioaerosol emissions form in a sanitary wastewater treatment plant.
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Material and Method: This cross-sectional study was carried out in different units of a sanitary wastewater treatment plant. For this purpose, air samples were collected on blood agar and dextro agar in an Andersen single-stage sampler with flow of 28.3 lit/min for 10 minutes. Collected samples were shipped to the lab immediately and incubated for 48 hours. Then, incubated samples were counted for colonies concentration.
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Result: Based on the result of this study, the mean density of bacterial and fungal bioaerosols in all wastewater treatment plants were 412.86±23.30 and 53.72±23.99 CFU/m3, respectively. Microbial contamination of the air within a kilometer away from the site (control areas) was 17 times less than its average density.
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Conclusion: Wastewater treatment processes can contaminate the air surrounding the plant, particularly with bacteria bioaerosols. Therefore, it is necessary to control the emissions and protect the health of workers against risks arising from exposure to bioaerosols.
M. Ghasemkhani, M. Sheikh Alishahi, M. Asghari,
Volume 4, Issue 2 (7-2014)
Abstract
Introduction: IBioaerosols are usually defined as aerosols or particles with microbial, plant or animal origin. Textile industries are of the working environments in witch workers are exposed to bioaerosols. In textile industry, the highest contamination concentration is the belonged to carding step. Since, textile industry in iran is native and a large number of employers are working in this industry, this study was undertaken to assess bacterial bioaerosols concentration in a textile in industry in iran.
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Material and Method: In cross-sectional study was done in different units and also outdoor environment of a cotton textile plant. The concentration of bioaerosols were sampled and measured according 0800 method presented by NIOSH, during summer. Diagnosis of type of colonies and bactories, grown on blood agar, was done using gram staining.
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Result: The mean bioaerosols concentration obtained the highest and lowest values in outdoor environment (94±9.5 CFU/m3) and unit 2 (Ring site) (64±18.0 CFU/m3), respectively. The mean difference of bioaerosols concentration in unit 1 (Carding sites) and unit 2 (Ring site), was statistically significant in this study. The highest number of bioaerosols colony was for staphylococcus Epiderms (N=1743) and the lowest number was for streptococcus pneumonia (N=64) in the whole plant.
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Conclusion: Although the bioaerosols concentration obtained in the present study is lower than those reported in other studies, these values are above the threshold recommended.
Farnaz Valedeyni Asl, Sadegh Hazrati, Mohsen Arzanlo, Mehdi Fazlzadeh,
Volume 8, Issue 1 (4-2018)
Abstract
Introduction: Microorganisms in hospitals are potential sources of infection to patients and staffs. Bioaerosol exposure is associated with a vast range of adverse health effects including infectious diseases, acute toxic effects, allergy. This study aimed to survey the type and density of bioaerosols in ambient air of different wards of educational hospitals Ardabil in 2016.
Material and Method: This cross-sectional study was conducted in 2 educational hospitals of Ardabil city in 2016. ZTHV02 sampler and Tryptic soy Agar along with Cycloheximide antibiotic were used to evaluate and determine the airborne bacterial counts. The average sampling time was 10 minutes. Air samples were transported to the lab just after sampling and incubated for 48 hours at 37 ºC. Then, raised colonies were counted. Bacterial density was expressed as CFU/m3 ± SD.
Result: Mean bacterial concentrations were 10.3 and 23.4 CFU/m3 in Imam and Alavi hospitals, respectively. X-ray room in Imam Khomeini hospital and ICU room in Alavi hospital had the highest bacterial count. But, the least bacterial loads were observed in ICU and Angiography wards of Imam Khomeini and CTSCAN ward in Alavi hospitals. The most prevalent bacteria species isolated from air samples of Imam hospital was Enterococcus spp followed by Pseudomonas spp, coagulase negative Staphylococci spp and Non -Enterococcus group D Streptococci and for Alavi hospital; Coagulase negative Staphylococci spp followed by Psodomonas spp, Klebsilla spp and, Enterococcus spp.
No significant correlations were found between bacterial counts, temperature and humidity of the sampling sites. However, bacteria density significantly were higher in morning shift comparing to evening shift (P <0.05).
Conclusion: High concentration of airborne bacteria bio-aerosols in Ardabil hospitals can be important health risks for health workers and the patients.
Zahra Alaei, Roohollah Ghasemi, Mohammad Reza Pourmand, Ali Karimi, Ensieh Masoorian, Farideh Golbabaei,
Volume 12, Issue 2 (6-2022)
Abstract
Introduction: Volatile organic compounds are the most common pollutants in the air, and among them, toluene is the most common form, which is toxic resulting in liver and kidneys damages. Regarding the fact that this compound is widely used in various chemical industries, implementing an efficient method for controlling its concentration is of great importance. The comparative survey of the capability of virgin activated carbon with the one immobilized by pseudomonas putida PTCC, and also the performance of the biofiltration system involving pseudomonas putida bacteria immobilized on activated carbon for the adsorption and degradation of toluene from the air as well as regenerating the activated carbon were aimed in the present study.
Material and Methods: The microbial growth process was initiated by incubation of pre-culture in a rotary shaker, at 150rpm overnight. After 4 days, the strain pseudomonas putida, PTCC No: 1694 was immobilized on a certain amount of activated carbon. Subsequently, an airstream containing toluene was introduced into the biofilter, and the inlet and outlet concentrations of toluene were measured.
Results: The obtained results illustrated that the increase in the volume of the media and decrease in the gas flow rate significantly enhances efficiency. The great performance of the biofilter was confirmed by the high efficiency of the immobilized activated carbon which exhibited 89% yield during 14 hours. On the second cycle, the biofiltration system was able to adsorb toluene at an efficiency of 81%, while the virgin activated carbon exhibited far less efficiency with the value of 28%.
Conclusion: The provided results demonstrated the feasibility and reusability of the biofilter system for toluene removal. The proposed technique also extends the activated carbon’s capacity, which could be a potential solution to re-use the activated carbon in industrial applications.
Saba Kalantary, Mohammad Reza Pourmand, Ensieh Masoorian, Mirghani Seyd Someah, Zahra Barkhordarian, Sara Hajinejad, Farideh Golbabaei,
Volume 14, Issue 2 (6-2024)
Abstract
Introduction: Protection of the respiratory system has been a vital, and for this purpose, various solutions have been proposed, including the use of masks. One of the most important parameters to measure the effectiveness of the mask against the penetration of microbial agents. The present study was conducted with the aim of evaluating the bacterial and particle filtration of medical masks.
Material and Methods: To assess bacterial performance, the national standard 6138, compliant with EN14683, and Type I medical masks were utilized. Staphylococcus aureus bacterial suspension was prepared and passed through the mask using a nebulizer and through an impactor with a flow rate of 28.3 l/min. Plates containing soy agar were placed in the impactor. Subsequently, all plates were incubated, and the bacterial filtration efficiency (BFE) of the masks was determined by counting the bacterial colonies that passed through the mask’s media as a percentage of the total bacteria. It is worth noting that the pressure drop and particle filtration efficiency were also determined for all masks
Results: Based on the results of the particle removal performance for the particle size of 3 µ, the masks were categorized into three groups with efficiency above 99%, above 95% and 90%. According to the standard, all masks had an acceptable pressure drop below 40 Pa. The acceptable bacterial filtration rate for type I masks should be above 95%. The results showed that type A and B masks have an acceptable bacterial filtration rate and there is a significant correlation between the types of masks examined in terms of bacterial and particle efficiency.
Conclusion: The results showed that different types of masks under investigation have significant differences in terms of particle capture efficiency and bacterial filtration performance. In addition, there is a significant correlation between bacterial and particle filtration efficiency.
