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Objective: To analyze and understand the level of occupational external radiation personal dose of radiation workers in a hospital, and provide a reference for radiation protection. Methods: In May 2023, the personal dose monitoring data of all radiation workers in the hospital from 2018 to 2022 were collected, and their occupational external radiation exposure levels were analyzed and evaluated. All radiation workers were divided into radiation diagnosis, radiotherapy, interventional radiology, and nuclear medicine according to their occupational categories. Results: A total of 1626 person-times were monitored from 2018 to 2022, and the average annual effective dose per person (0.13-0.36 mSV) was lower than the national limit of 20 mSv. The average annual dose of nuclear medicine was the highest (0.36 mSv), and interventional radiology was lower (0.13 mSv). The average annual dose of individuals was the highest in 2020 (0.24 mSv) . Conclusion: The average annual effective dose per person of radiation workers in this hospital is lower than the national standard, and it is still necessary to strengthen the inspection of the wearing of personal dosimeters and the using of protective equipment for radiation workers.

Objective: To investigate the individual external dose level of some interventional radiology staffs from 2016 to 2020 in Tianjin City. Methods: All 2068 interventional radiology staffs who were included in the work of the Radiation Monitoring Project from 2016 to 2020 were selected as study subjects in March 2021. The individual dose monitoring results of interventional radiology staffs of different ages, working years, time and medical institutions were analyzed. Results: Among 2068 interventional radiology workers, 1406 (67.99%) were male and 662 (32.01%) were female. The age was 44.6 (39.2, 50.3) years, and the working years was 10.5 (4.3, 14.6) years. The annual effective doses per capita of 40-49 age group and ≥50 age group were higher than that of 30-39 age group ( P <0.05) . The annual effective dose per capita of 5-9 working years was higher than that of <5 working years, and the annual effective dose per capita of 10-29 working years was higher than that of 5-9 working years ( P <0.05) . The median per capita annual effective dose of the interventional radiology staffs was 0.164 mSv. There were 1976 interventional radiology staffs with an annual effective dose of <0.50 mSv/a (95.6%) . The collective dose distribution ration SR (0.5) was 41.1%. The difference of effective dose per capita in each year was statistically significant ( H =19.23, P <0.05) . The per capita annual effective dose of interventional radiology staffs in tertiary medical institutions was higher than that in secondary medical institutions, and the difference was statistically significant ( P <0.05) . Conclusion: The personal dose of interventional radiology staffs in Tianjin City is at a low level. It is necessary to emphasize the radiation hazard protection of interventional radiology staffs in tertiary medical institutions, 40-49 years old, ≥50 years old age groups and 5-9, 10-29 working years groups.

As an essential form of material migration on the surface of the earth, soil erosion is one of the primary causes of soil fertility reduction and environmental degradation. Quantifying soil erosion rate is the precondition and foundation for regional soil erosion control. The Pu isotopes produced by atmospheric nuclear tests have a long half-life after settling into the soil and could be easily adsorbed by clay minerals and organic matter. In recent years, Pu isotopes have become principal trace elements in the quantitative studies of soil erosion rate, especially with the development of mass spectrometry technique. The measurement time of Pu isotopes has been shortened, and the sensitivity of Pu isotopes has been improved, both of which help improve the radionuclide tracing technology for soil erosion. Here, we summarized the distribution characteristics as well as the adsorption and migration behavior of Pu isotopes in soil. We described the basic principles for the application of Pu isotopes in tracing soil erosion, and elaborated the research progress concerning relevant applications. Moreover, we compared the applicability of Pu isotope and 137 Cs tracing techniques in soil erosion research and proposed research directions in the future. This review would provide a reference for the scientific applications of Pu isotope tracing technique in soil erosion research.

Objective: To monitor the change of the radiation dose of the rabbits which were implanted rasioactive 125I seed into the normal laryngeal tiseue at different time,and to evaluate the safety of radiation protection. Method: Sixty New Zwaland rabbits, weighing 2.15-2.30 kg，were randomly divided into 5 groups:7 d,1month,2 month,4 month group and the control group, 12 rabbits in each group Iodine-125 of 0.8 mCi were implanted into the right side of the first trachea ring. At the different time and different distance, the surrounding radiation dose was measured after 4 months of implanting. The results were analyzed in statistics. Result: With the increase of the distance and the prolong of the time, the radiation dose was decreasing，and with the increase of distance,the radiation dose decreased slowly. At the site of 1 meter from the seeds, the detected dose is close to the natural background radiation dose. Conclusion: The clinical application of radioactive 125I seed interstitial implant is easy to protected,the surrounding close contacts is satety., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: To explore the dose-length product calibration method for pencil ionization chamber in cobalt beams., Methods: The PTW TM30009 ionization chamber was placed into the central hole of T40017 head phantom and irradiated 60 s in 20 cm x 20 cm cobalt beam. The charge was collected with UNIDOS electrometer. Absorbed doses were measured with TM30013 0.6 mL farmer-type chamber under the same condition. The CT chamber calibration factor was expressed in dose-length product. Dose linearity and spatial response were also investigated., Results: The calibration factor in dose-length product was derived from measured data. Dose linearity and spatial response were good in cobalt beams., Conclusion: It is feasible to calibrate the CT chamber in cobalt beams for patient dose evaluation in MVCT.

Based on the total radiation and photosynthetically active radiation (PAR) observations with net radiometer (CNR1) and quantum sensor (Li-190SB) in 4 ChinaFLUX forest sites (Changbaishan, Qianyanzhou, Dinghushan, and Xishuangbanna) in 2003-2008, this paper analyzed the uncertainties and the radiometers performance changes in long-term and continuous field observation. The results showed that the 98% accuracy of the total radiation measured with CNR1 (Q(cNR1)) could satisfy the technical criterion for the sites except Xishuangbanna where the Q(CNR1) was averagely about 7% lower than Q(CM11), the radiation measured with high accuracy pyranometer CM11. For most sites, though the temperature had definite effects on the performance of CNR1, the effects were still within the allowable range of the accuracy of the instrument. Besides temperature, the seasonal fog often occurred in tropical rain forests in Xishuangbanna also had effects on the performance of CNR1. Based on the long-term variations of PAR, especially its ratio to total radiation in the 4 sites, it was found that quantum sensor (Li-190SB) had obvious performance attenuation, with the mean annual attenuation rate being about 4%. To correct the observation error caused by Li-190SB, an attempt was made to give a post-correction of the PAR observations, which could basically eliminate the quantum sensor's performance attenuation due to long-term field measurement.

Objective: To investigate the condition of microwave radiation pollution from mobile phone base station built in populated area., Methods: Random selected 18 residential districts where had base station and 10 residential districts where had no base stations. A TES-92 electromagnetic radiation monitor were used to measure the intensity of microwave radiation in external and internal living environment., Results: The intensities of microwave radiation in the exposure residential districts were more higher than those of the control residential districts (p < 0.05). There was a intensity peak at about 10 m from the station, it would gradually weaken with the increase of the distance. The level of microwave radiation in antenna main lobe region is not certainly more higher than the side lobe direction, and the side lobe direction also is not more lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place in someplace. The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were more lower than those of outside the aluminum alloys security net (p < 0.05), but the inside or outside of glass-window appears almost no change (p > 0.05)., Conclusions: Although all the measure dates on the ground around the base station could be below the primary standard in "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside or inside of a few window was even higher beyond the primary safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.

In order to improve the diagnostic quality of X-ray device and to promote the implementation of radiation protection in accordance to the ICRU definition and ICRP classification standards for measuring radiation harm to human body, we have made a number of tests, including the kinetic energy released by ionizing air, the Half-value layer, the output dose coincidence, the High contrast resolution, the Consistency between visual light field and project X-ray field, and the Focus of X-ray tube. We have also analysed the measured data and results. The tests were conducted on the XEB150L-20 made by Shimadzu Co. in the middle of 1990s.

Twelve camphor (cinnamomum camphora) tree bark samples were collected from Hiroshima and Kyoto, and the matrix element composition and morphology of the outer surface of these camphor tree bark samples were studied by EDXS and SEM respectively. After a dry decomposition, DOWEX 1-X8 anion exchange resin was used to separate uranium from matrix elements in these camphor tree bark samples. Finally, 235U/238 U isotope ratios in purified uranium solutions were determined by MC-ICP-MS. It was demonstrated that the outer surface of these camphor tree bark samples is porous and rough, with Al, Ca, Fe, K, Mg, Si, C, O and S as its matrix element composition. Uranium in these camphor tree bark samples can be efficiently separated and quantitatively recovered from the matrix element composition. Compared with those collected from Kyoto, the camphor tree bark samples collected from Hiroshima have significantly higher uranium contents, which may be due to the increased aerosol mass concentration during the city reconstruction. Moreover, the 235 U/23.U isotope ratios in a few camphor tree bark samples collected from Hiroshima are slightly higher than 0.007 25.

Background & Objective: Medical imaging-guided 125I radioactive seed implantation is a new method of mini-invasive therapy. As a component of combined therapy for malignant tumors, 125I implantation has benefits of minimal invasion, accurate position fixing, and certain clinical effects, and has been widely applied to treat tumors at present. Also the environmental phototoxis and radiation protection have been highly regarded. This study was to investigate the environmental radiation dose monitor after 125I radioactive seed implantation., Methods: From Oct. 2004 to Dec. 2005, 20 patients with malignant tumors were randomly selected in this study after 125I radioactive seed implantation. Environmental radiation dose was detected right after operation and 2, 4 and 6 months later with gamma-ray equipment., Results: With the increase of the distance from radioactive source, the radiation dose decreased quickly. The detected dose was close to a natural background radiation dose at a distance of 50 cm from radioactive source. With time passing, the environmental radiation dose was attenuated and the detected dose was close to natural background after 6 months., Conclusions: Addition to the isolation and shielding protection before and after 125I radioactive seed implantation, distance protection and time protection should be considered. With necessary strict protection, 125I implantation is safe to patients and environment.

Objectives: To investigate intensity of extremely low frequency magnetic field (ELFMF) emitted from cathode-ray tubes (CRT) of monitors in various directions and to find ways to avoid its influence., Methods: Two hundred CRT monitors and 10 monitors with liquid-crystal display (LCD) were selected. Their ELFMF was detected for three times in front of the monitor at an interval of every 5 cm from 0 cm to 50 cm, as well as at various directions from the monitor., Results: Intensity of ELFMF significantly attenuated at regular operating position (30 - 40 cm) from 0 cm to 50 cm in front of both 38 cm and 43 cm CRT monitors (P < 0.05). Intensity exceeded 0.4 microT both within 15 cm and 10 cm in front of 38 cm and 43 cm monitors. The highest intensity was found at the upright top position of both kinds of monitors, 9.54 microT for 38 cm monitor and 6.38 microT for 43 cm one, respectively., Conclusions: It is suggested to keep away from monitor screen as possible when operating a computer, to reduce unnecessary operation in front of a monitor screen, and to shorten operating time. To avoid more hazards from interactive interference between computers, it is necessary to increase distance between monitors.

Absorbed doses and the dose distributions at important tissues and organs in an anthropomorphic phantom are measured using TLD under the TBI conditions. The dose for each tissue or organ is also estimated and monitored for TBI treatment.

The ultraviolet-vacuum ultraviolet emission standards including high temperature argon wall-stabilized arc and synchrotron radiation were introduced. The spectral radiometric characteristics of an argon wall-stabilized arc and a deuterium lamp calibrated by synchrotron radiations were studied as ultraviolet-vacuum ultraviolet radiation scales. With the spectroradiometris system of high precision established by us, the comparison of scales between the argon wall-stabilized arc and the synchrotron radiations in the 165-300 nm range has shown agreement to within +/- 5%.

Cancer incidence(1950-1995) among 27,011 medical X-ray workers in comparison with 25,782 non X-ray medical specialists between 1950 and 1980 in China was investigated. The average cumulative dose received by the X-ray workers also reconstructed by retrospective dosimetry methods. Significant cancer risk was seen among medical X-ray workers(RR = 1.2). Significantly elevated risks were found in leukemia, cancer of skin, female breast, lung, liver, bladder and esophagus, the RRs were 2.2, 4.1, 1.3, 1.2, 1.2, 1.8 and 2.7 respectively. The patterns of cancer risk were associated with years since beginning of X-ray work, age and calendar year of initial employment and cumulative dose suggest that the risks of leukemia, skin cancer and female breast cancer, possibly thyroid cancer were related to occupational exposure to X-rays. A significant cancer risk could be induced by prolonged exposure to low dose ionizing radiation when the cumulative dose reached a certain level.

Two Geiger-Mueller radiation dosimeters, equipped with data recorders, were placed in the recoverable satellite launched on Oct. 20, 1996. The data recorder was used to record the count rate of proton acquired by the Geiger-Mueller dosimeter dynamically. From the obtained data, the area of high proton flux and the contour map of South Atlantic Abnormal was plotted.