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Objective To detect the radiation of 131I in treatment site of a grade A tertiary hospital. Methods A total of 25 patients with thyroid cancer were administrated 131I at a total dose of 82880 MBq. After administration, the ambient dose equivalent rate of the ward was detected with X- and γ-ray detectors. After patient discharge, surface contamination of the ward was detected with α/β surface contamination meter. During patient hospitalization and on the day of discharge, air samples were collected from 131I treatment site and office area. The air samples were measured using a HPGe γ-ray spectrometer and the concentration of 131I in air was calculated. Results The ambient dose equivalent rate in the ward ranged from 0.15 to 0.46 μSv/h. Before ward cleaning, surface contamination ranged from 0.53 to 40.1 Bq/cm2 and the highest value was recorded on the toilet. Within 4 h after administration, the concentrations of 131I in air in treatment site and the corridor of the office area were 1.74 Bq/m3 and 0.66 Bq/m3, respectively. The ventilation air flow rate in the treatment site was 0.50 m/s. Ventilation decreased the concentration of 131I in air by 29.7%, 79.7%, and 53.3% compared with the previous day during hospitalization and on the day of discharge. Conclusion The radiation of external exposure of 131I in the treatment site is low and the shielding is effective. Before ward cleaning, the surface contamination is lower than the required limits except for the toilet. Ventilation is the primary way to reduce the concentration of 131I in air.
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PURPOSE: The aims of this study were to evaluate the dentist's awareness and the actual status of infection control of noncritical dental instruments. MATERIALS AND METHODS: 40 dental clinics in Daejeon, South Chungcheong, North Chungcheong and North Jeolla provinces were surveyed. The questionnaire was delivered to the dentists belonging to those clinics, and the awareness and the practice of infection control were examined. The microbial contamination on the surface of five noncritical instruments (impression gun, light curing unit, 3-way syringe, shade guide, and dental floss dispenser) used by them was measured with an ATP luminometer. Correlation analysis between the awareness and the actual state of infection control was conducted. RESULTS: Awareness and frequency of infection control was highest in the 3-way syringe. Surface disinfection using disinfectant was most frequent in all instruments. 3-way syringes and shade guides were less contaminated than impression guns, light curing units, and dental floss dispensers. CONCLUSION: 3-way syringes had a significant correlation between user awareness of infection control and surface contamination, and the higher awareness, the lower the contamination measurement was shown.
Subject(s)
Humans , Adenosine Triphosphate , Dental Clinics , Dental Devices, Home Care , Dental Instruments , Dentists , Disinfection , Firearms , Infection Control , SyringesABSTRACT
Objective: In late 1970s, occupational exposure to antineoplastic agents was reported. Various countries, including Japan, have published guidelines for handling antineoplastic agents. Surveys are still being conducted to determine the levels of environmental exposure to antineoplastic agents at individual hospitals, and incidents of contamination are often reported. This study provides details regarding a literature survey conducted to evaluate the actual state of environmental contamination by antineoplastic agents and identify the related issues in order to promote environmental monitoring.Methods: The literature search was carried out from January 1, 1990 to July 31, 2017. PubMed and Ichushi-Web were searched with the following keywords: “antineoplastic agents,” “occupational exposure,” “surface contamination,” and “environmental monitoring.”Results: Following the literature search, 117 papers were included in the analysis. The findings showed that contamination by antineoplastic agents was widely reported in hospitals and places where antineoplastic drugs were not handled. The findings of this study regarding the actual state of environmental exposure are partial, as there is a lack of information on retail pharmacies and homes of outpatients who have received chemotherapy.Discussion: Therefore, further investigation is warranted. In addition, according to the current Japanese guidelines, published in 2015, environmental surveillance is not required to reduce contamination by antineoplastic agents. To promote environmental monitoring, we feel that it is necessary to determine a new survey method and the clarify optimum interval of environmental monitoring.
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Objective:To summarize the performance of surface contamination meters was using through applied national standard to calibrate them so as to provide helpful suggestion for radiation protection.Methods: 18 surface contamination meters were enrolled in this research. Depend on the national standard (GB/T 5202-2008/IEC 60325:2002) to implement calibration. In the calibration, two groups of241Am alpha plane source and two groups of204T1 beta plane source were chosen as standard source. The holder was used to fix the distance of measurement between source and detector, and then the efficiency of apparatus, statistical fluctuation and relative inherent error were measured depended on the standard procedure.Results: The efficiency of apparatus of 18 surface contamination meters in detection forαray mainly focused on 20%-40%, and forβ ray, it mainly focused on 20%-60%. All of statistical fluctuations of 18 meters forαray were lower than 10%, and forβ ray, there were 14 meters were lower than 10% and 4 meters focused on 10%-20%. In the measurement of relative inherent error, most of results were lower than 6%.Conclusion: The performances of 18 surface contamination meters conform with national standards, although individual indicator of individual apparatus still lower than the level of same kind of apparatus. This paper recommends paramedic should pay attention to maintain the apparatus, and ensure the normal function and measurement accuracy of apparatus so as to provide strong support for radiation protection.
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PURPOSE: To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS: A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non-quantitatively. RESULTS: All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION: The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.
Subject(s)
Acetone , Ceramics , Ethanol , Spectrum Analysis , Steam , UltrasonicsABSTRACT
PURPOSE: To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS: A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non-quantitatively. RESULTS: All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION: The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.
Subject(s)
Acetone , Ceramics , Ethanol , Spectrum Analysis , Steam , UltrasonicsABSTRACT
A constatação de que Bacillus cereus é um microrganismo que constitui problema especial em plantas de processamento de alimentos, dentre as quais se incluem restaurantes universitários, levou a realização deste trabalho, que teve como objetivo contribuir para a avaliação de riscos a que se expõem os usuários de cozinhas de grande porte, por meio da identificação de pontos do ambiente, a partir dos quais o microrganismo pode ser transferido aos alimentos. A presença de B. cereus foi detectada em 38,3 por cento das amostras de equipamentos e utensílios estudados. As contagens atingiram até 5,7x10² UFC/cm², sendo que os valores mais elevados foram obtidos a partir de amostras dos setores de distribuição, indicando a importância destes locais como fontes potenciais de transmissão do microrganismo para os alimentos.
The confirmation that Bacillus cereus is a microorganism that represents a special problem in food processing plants, such as university cafeterias, inspired this work, the scope of which was to evaluate the risks consumers are exposed to by identifying the contamination points from whence the microorganism can be transferred on to food. The presence of B. cereus was detected in 38.3 percent of the equipment and utensils studied. Counts of up to 5.7x10 ² CFU/cm² were found, with the highest values being found in samples from distribution sectors, indicating the importance of these areas as potential sources of microorganism transmission on to food.