Journal of Health and Safety at Work

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Introduction: Possible contamination in nuclear medicine centers, in addition to health problems, affect the tests and much effort and cost is required for decontamination. Given the effects of ionizing radiation on human health, rules and regulations have been enacted to avoid contamination, that in working with radioactive materials should be followed to minimize them.

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Material and Method: After mapping of nuclear medicine centers in the province, areas that should be studied for measuring the amount of radioactive contamination were determined. The site selection for the tests were based on the area in which the possibility of further contamination were existance. After measuring the background count rate the radioactive contamination in studied areas were performed using Wipe Test.

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Result: The mean level of background contamination in centers 1, 2 and 3 were 1.75±0.150 μCi, 4.43±0.615 μCi and 2.47±0.055 μCi, respectively. In center 1, only region of Hood pollution was much higher than the permissible limit. In center 2, radioactive contamination of the waiting room, patient rooms, warehouse radiotracer, control room, hood, desk and floor center was exceeded. Also, in center 3, contamination of the doorway, hallway patients, control room, hood, desk, sink, cabinets, room and floor imaging injection (control), respectively, were higher than the permissible limits.

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Conclusion: In centers 1 and 2, most of the radioactive contamination occurred under the hood due to labeling of radiopharmaceuticals activity. Also, in center 3, the highest contamination rate belonged to patients’ corridor that could be due to frequent the area. According to this subject, necessary measures in this regard should be considered by the department responsible for health physics.

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Introduction: During recent years, carcinogenic effects of X-ray have been proven. Todays, lead is used in many equipment such as  coats, thyroid shield, and gloves for body protection against X-ray. However, these equipments have several disadvantegous including toxicity, heaviness, and inflexibility. Hence, newer methods like protective semisolid products (cream, ointment) for topical application are being replaced. Therefore, the feasibility of using an ointment containing bismuth oxide nanoparticles (Bi2O3) as a X-ray adsorbent was evaluated in this study.
 

Methods and Materials: First, synthesis of Bi2O3 and then formulating it in the form of ointment was investigated. In this study, X-ray device and dosimeter was employed to check the X-ray absorption in different thickness of bismuth oxide nanoparticles ointment.
 

Results: In dosimetry test, the protective effect of the ointment containing Bi₂O₃ nanoparticles was evaluated significantly (P<0.05) better than control group and equal sheet lead group. Dosimetry tests showed that the bismuth oxide nanoparticles ointment and cream absorb  56% of the radiation whereas this value is  41% for lead. K absorption edge for bismuth is higher than other metals and its nanoparticles have more absorbent surface to volume ratio (S/V).
 

Conclusion: It seems that due to higher atomic number and lower toxicity, Bi₂O₃ nanoparticles have better efficiency in X-ray absorbtion, comparing to the lead. Cream and ointment of bismuth oxide nanoparticles can be used as X-ray absorbant for different professions such as physicians, dentists, radiology experts, and operating room staff and consequently increase health and safety of these employees.

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Introduction: The important parameters for evaluating the performance of particle filtering respirators in international standards are the filtration efficiency and respiratory resistance of the mask filter against airflow passage. To improve nanofiber filtration efficiency while creating the least breathing difficulty for the wearer, various research has been or is being conducted worldwide. This study investigated the effect of using polyacrylonitrile (PAN) nanofiber composite membrane and montmorillonite clay nanoparticles (MMT) in enhancing particle-filtering respirators’ filter performance, achieving higher filtration efficiency while maintaining optimal respiratory resistance conditions.
Material and Methods: First, PAN polymer solution containing zero, 1%, 2%, 3%, and 5% MMT nanoparticles was prepared, and then PAN/MMT nanofiber composite membrane was synthesized in an electrospinning machine. Filtration efficiency was measured in diameter range of 0.3, 0.5, 1, and 3 microns using sodium chloride aerosol. Additionally, filter breathing resistance was measured at flow rates of 30, 85, and 95 liters per minute.
Results: The efficiency of synthesized composite nanofilters for particle purification can be improved by adding MMT nanoparticles to PAN nanofibers. Optimal MMT concentration was found to be 2%. This addition resulted in an increase in filtration efficiency for particles with sizes of 0.3, 0.5, 1, and 3 microns by 4.2%, 4.88%, 3.77%, and 2.75% respectively without causing significant difference in respiratory resistance. Improved filtration efficiency can be attributed to enhanced morphology of composite nanofilters resulting from addition of MMT nanoparticles. Adding 2% MMT nanoparticles to PAN nanofibers resulted in uniform distribution and smaller fiber dimensions which did not significantly affect Packing density and porosity.
Conclusion: If 2% of MMT nanoparticles are added to PAN nanofibers and used to produce particle respirators, resulting respirator will exhibit a 4.2% increase in particle filtration efficiency without increasing breathing difficulty for user. This result can help protect users from particulate pollutants in air pollution conditions.