Journal of Health and Safety at Work

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.

Introduction: Whole-body vibration is one of the factors which may have adverse effects on the comfort of passengers and crew of rail transportation vehicles. In this study, the probable impacts of whole-body vibration were explored on the convenience of the passengers of Tehran metro.
 

Material and methods: Planning, measurement, and pre-analysis calculations were mainly done based on ISO guidelines No. 2631-1, 4. Moreover, measurements and calculations were done using SVAN 958 sound & vibration analysis and Microsoft Excel software, respectively.
 

Results: Average calculated RMS acceleration values on the levels of seat cushion, seat back, and legs were 0.57, 0.44, and 0.64 m/s² on the dominant axes, and total r.m.s acceleration in all these three levels equaled to 1.02 with the standard deviation of 0.11 m/s². Mean Vibration Dose Value (VDV) of total exposure in the minimum and maximum exposure durations were 6.44 and 9.63 m/s ^1.75, respectively.
 

Conclusion: Calculated amounts of dominant axes were mainly ranked as “relatively unpleasant” in the convenience limits of ISO 2631-1, but the total calculated amount of exposure based on WRMS was at “unpleasant level”. The measured VDV amounts were mostly on the z axis, as the dominant one.

Introduction: Nowadays, many modern industries require an environment with no contamination by particles and bacteria. An enclosed clean room environment is a place where parameters such as airborne particles, temperature, humidity, air pressure and air flow pattern is controlled. The aim of this study was to evaluate functional parameters of a clean room  in a selected pharmaceutical industry.  

Material and Method: This study was an experimental study conducted in 2015 in a pharmaceutical industry.  The air flow rate and flow rate with airflow capture hood was used and multi sensor devices for measuring temperature, humidity and pressure of multi-sensor device. HEPA filter leakage test and counting concentration of particles in the cleanroom was done according to the ISO 14644 – 3(2005) standards using aerosol photometer and aerosol generator. In this study, 6 clean room relating to the 3 cleanliness classes B, C and D (in accordance with standard EU GMP) were evaluated. Meanwhile, both the 2 and 3-dimensional flow model using Computational Fluid Dynamics Software was simulated in this study.   

Result: Measuring the parameters flow rate and air velocity, temperature (average temperature 20 ° C), relative humidity (below 50%), pressure (pressure less than 15 psi) for every three classes of cleanliness are all acceptable and less than the proposed standard. Furthermore, the results of modelling showed that the pattern of air flow in the room is correct paths in circulation. In the case of leakage test filters, the filter 29 filters tested 5 was leaking and ultimately determine the HEPA filters remove particles that average efficiency is 99.99%.

Conclusion: This study showed that the high volume and good quality of air entering the clean room affect the optimal efficiency and air flow rate, pressure drop and air penetration of the HEPA filters Also, the results of study show that the concentration of airborne particles in clean room is depend on the air flow rate and speed and adopting a good air flow pattern will affect the particle concentration.