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Objective To investigate the radionuclide content in food in Chongqing, China by conducting a survey on the radioactivity in food. Methods A total of 114 samples of vegetables, grain, milk powder, and tea were collected in Chongqing. The samples were dried, pulverized into powder, added into Marinelli beakers, and then measured for radionuclides using a high-purity germanium gamma spectrometer (GEM40P4-765). Results The mean activity concentrations of natural radionuclides 238U, 232Th, 226Ra, and 40K in food in Chongqing were (0.396 ± 0.510), (0.199 ± 0.296), (0.140 ± 0.209), and (119.250 ± 105.470) Bq/kg, respectively. The contents of radionuclides in different foods were significantly different (P < 0.05). The mean activity concentration of the artificial radionuclide 137Cs was (0.091 ± 0.308) Bq/kg, and the mean activity concentration of 90Sr measured in nine tea samples was (1.243 ± 0.860) Bq/kg. Conclusion The contents of radionuclides in food in Chongqing are lower than the national standard limits, but the safety of radioactivity in food still needs to be taken seriously, and long-term surveillance of radioactivity in food is needed.
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Objective To analyze and set up the effective dose of different ionizing radiation for tunnel construction workers. Methods A total of five tunnels constructed using drilling and blasting methods were selected as the research subjects using the convenient sampling method. The workplace γ radiation effective dose, radon concentrations, and radioactive activity concentrations were detected, and on-site surveys were conducted to estimate the internal and external irradiation doses and total effective doses for workers in different work sites. Results Radiological hazards in tunnels constructed using drilling and blasting methods included radon and its progeny, γ radiation, radioactive dust (uranium-238, radium-226, thorium-232, and potassium-40) and others. The average total effective dose of ionizing radiation exposure for tunnel construction workers was (6.730 1±1.541 1) mSv. The average dose of radon and its progeny was (6.163 0±1.512 8) mSv, radioactive dust was (0.014 6±0.009 1) mSv, γ radiation was (0.552 6±0.138 7) mSv. The dose of radioactive dust of radon and its progeny was 0.24%. Radon and its progeny contributed more to the radioactive dose than radioactive dust and γ radiation (all P<0.05). Among all the radioactive dusts, the dose contribution ranked from highest to lowest was thorium-232, uranium-238, and radium-226. Conclusion For tunnel construction workers, the largest contribution to the effective dose of ionizing radiation exposure is from radon and its progeny for internal irradiation, followed by γ radiation for external irradiation. The contribution of radioactive dust to internal irradiation dose can be considered negligible.
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Objective To analyze the problems and solutions in the diagnosis of a patient with occupational radiogenic neoplasms. Methods The dose conversion method was selected in dose estimation. Personal dose equivalent, skin absorbed dose, and reported detection data were converted into red bone marrow absorbed dose. The upper 95% confidence limit of the probability of causation (PC 95%) was calculated. Results The PC 95% of cancer due to radiation in the worker was 66.38%, which suggested occupational radiogenic neoplasms. Personal dose data were missing in dose estimation. The current dose estimation standard lacked bedside radiography and CT operation type, and the dose conversion formula was not perfect. Conclusion In the judgment of occupational radiogenic neoplasms, the estimated dose showed uncertainty. There is an urgent need to formulate and promulgate dose estimation standards that are operational and in line with the current development of radiological diagnosis and treatment technology and equipment.
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@#A large number of people would be exposed to irradiation in large-scale nuclear and radiation accidents or nuclear terrorist attacks. Therefore, it is urgent to establish rapid and high-throughput biodosimetry for in triage, providing a basis for emergency management. Imaging flow cytometry (IFC) possesses the high through put advantages of traditional flow cytometry and the sensitivity and specificity of microscope, and has a good application prospect in the research and development of rapid, automated, and high-throughput biological dose estimation technology. This article reviews the application progress of IFC in biodosimetry, and provides a reference for the development of biological dose estimation and detection equipment for large-scale nuclear and radiation accidents.
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Objective:To evaluate the radiation dose to the injured persons in a radiological accident, provide the guidance on the diagnosis and treatment of radiation injury, and provide the basis for determination of the level of radiological accident.Method:Firstly, the air-absorbed dose rates at 206 locations surrounding a X-ray device were measured by using LiF (Mg, Cu, P) thermoluminescence detectors and self-made radiation field measuring frames. Secondly, the spatial distribution of radiation level was obtained by fitting the inverse square law between absorbed dose rate and distance, which is used as the basis of dose estimation. Finally, based on the actual working conditions of injured operators, a parameter calculation method was proposed for estimating hand skin absorbed dose.Results:The air-absorbed dose rate surrounding X-ray beam outlet was higher than 1.0 mGy/h. The maximum air-absorbed dose rate value in the space of within 200 cm outside X-ray beam outlet was 262 μGy/h and the minimum value was 2.1 μGy/h, 2 orders of magnitude higher than environmental background level. During normal operation, the total absorbed doses to the hand skin of two injured female operators were 36.9 and 16.9 Gy, respectively. During extreme operation, the hand skin-received total absorbed doses to the two operators were 85.2 and 38.9 Gy, respectively. Under the occupational health standard GBZ 106-2020, the two persons had acute radiation skin injury of grade Ⅲ or Ⅳ on their hands.Conclusions:The results of hand skin exposure doses provide effective support for diagnosis and treatment of radiation injuries and for the determination of radiological accident level. The method used in radiation field reconstruction and dose estimation mentioned in this study can provide reference for the treatment in the similar radiological accident.
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According to the data released by the Civil Aviation Administration of China in 2020, there are more than 60000 pilots and more than 100000 flight attendants in China working with certificates in various airlines. The health of these aircrew is the basis for maintaining and continuing the smooth development of civil aviation. Aircrew are exposed to cosmic radiation at high altitudes. However, because the types of cosmic radiation are complex, changeable, and difficult to measure accurately, there is no definite conclusion as to whether it has any effect on the health of aircrew. This paper introduced the impacts of cosmic radiation on aircrew, reviewed the estimation of cosmic radiation dose at home and abroad, and summarized the cosmic radiation dose measurement methods and their limitations. It also pointed out the shortcomings of existing occupational health management of aircrew and put forward new suggestions on strengthening the health management of radiation hazards for aircrew.
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Objective:To evaluate biological dose and retrospective biodosimetry of a case of large area back skin injury caused by suspected interventional procedure.Methods:Peripheral blood from the patient was collected at about 7 months after interventional procedure, and the chromosomal aberrations in peripheral blood cells were analyzed to evaluate the retrospective biodosimetry using the correction factor of dose estimation, Dolphin′s model and Qdr method, respectively. Results:Based on the amounts of semi-automated dic and manually detected dic plus ring, the whole-body average absorbed dose of the victim was estimated to be 0.68-0.95 Gy by four different dose response curves. Over dispersion of dic or dic plus ring was also detected, and the efficiency of dose assessment was obviously increased using dic semi-automatic detection. Based on three different retrospective biodosimetry models, the estimated average absorbed dose was further corrected to be between 1.80-2.86 Gy, which was consistent with clinical diagnosis of degree Ⅳ radiation skin injury.Conclusions:A case of suspected radiation skin injury was confirmed by chromosomal aberration analysis and it’s biodosimetry was reconstructed, suggesting that the unstable chromosomal aberration analysis may be applicable to assess the retrospective biodosimetry of non-uniform local radiation exposure.
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Objective:To carry out investigation and analysis of an extensive skin radiation injury to the back accidentally caused by interventional procedure and to explore the problems faced in the event with emphasis on avoiding the reoccurance of similar events in the future.Methods:The data were collected by consulting the patient′s detailed medical history, collecting and analyzing clinical diagnosis and treatment data, tracking and observing their clinical manifestations and signs. The patient′s peripheral blood samples were also collected, together with the biological dose estimated and the equipment data collected on the site of the interventional treatment hospital.Results:The whole body dose to the patient was estimated to be 0.95 Gy. The typical values of kerma rate of radiation incident on the body surface due to fluoroscopic procedures were 373.5 mGy/min in subtraction modality and 47.8 mGy/min in fluoroscopy modality, respectively. The annual effective dose to the interventional radiologist was 20.51 mSv due to his operation in long-time radiation exposure conditions, higher than 3.09 mSv for other interventional radiologists with similar workload in the same department. The whole body and local clinical manifestations of the patients were in line with radiation injury. No clear diagnosis has been obtained in several hospitals, nor can obvious treatment outcomes be obsevered.Conclusion:Combined with the biological dose estimation result and clinical manifestations, the case was diagnosed as degree Ⅳ skin radiation injury. Radiation injury is closely related to whether the operation is conducted according to the standard and the output dose of X-ray machine. Non-specialized hospitals should strengthen clinical diagnosis and treatment of radiation injury.
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With the wide application of nuclear medicine and the increase in the number of related staff, the potential occupational health problems should receive enough attention. At present, the personal dose monitoring of most radiation workers in nuclear medicine is mainly based on the information on external exposure provided by thermoluminescence dosimeters whereas the routine internal exposure monitoring has not fully been carried out, thus resulting in underestimating their annual effective dose. Comprehensive personal dose monitoring is not only an important part of occupational health monitoring, but also a crucial means of occupational health management. In this paper, the characteristics of internal exposure in nuclear medicine were analyzed, the monitoring techniques and dose estimating method were introduced, and several commonly used softwares were listed, so as to comprehensively and objectively learn about the current internal radiation exposure of nuclear medicine workers, and to provide reference for health administration departments to formulate regulatory policies and protection requirements.
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Objective:To study the feasibility that using size-specific dose estimation (SSDE) to estimate organ dose and effective dose in coronary CT angiography (CTA).Methods:Totally 421 consecutive patients with coronary artery CTA were included and retrospectively analized. All patients were scanned using the 3rd generation dual-source Force CT with prospectively ECG gated axis scan mode. The size specific dose estimation(SSDE) for each patient was conducted by calculate water equivalent diameters with Radimetrics. The organ doses of heart, lung, liver and breast, were estimated with Monte Carlo method. Patient-specific effective dose was calculated as a weighted sum of simulated organ doses with the coefficients from ICRP 103. Linear correlation analysis was used to validate the relationship between SSDE and organ doses as well as effective dose, and to derive coefficients for patient specific dose estimation. The mean error rate was used to evaluate estimation accuracy.Results:The CTDI vol, SSDE and effective dose were (16.8±8.7)mGy, (20.8±8.8)mGy and (4.4±2.9)mSv, respectively. The linear fitting formula for estimating organ dose based on SSDE were: Y=1.2 X-6.4 ( R2=0.91, P<0.05, mean error 0.1%) for heart, Y=1.4 X-7.4 ( R2=0.91, P<0.05, mean error 7.9%) for breast, Y=0.89 X-4.6 ( R2=0.86, P<0.05, mean error 8.3%) for lung, and Y=0.36 X-1.8 ( R2=0.64, P<0.05, mean error -17.9%) for liver. The linear fitting formula for estimating the individual effective dose based on SSDE were: Y=0.21 X-1.2 ( R2=0.92, P<0.05, mean error 0.2%) for men, Y=0.39 X-2.2 ( R2=0.93, P<0.05, mean error 1.7%) for women. Conclusions:In coronary artery CTA, the absorbed dose of the organs and patient specific effective dose could be estimated with SSDE and the corresponding conversion coefficients, which will help to achieve personalized assessment and precise management of patient radiation dose and risk in clinical practice.
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Objective:To estimate the physical dose of an over exposed person working for industrial radiography.Methods:The main exposure parameters were obtained. The exposure duration was 8 min. The exposure pattern was external exposure by isotropic point radioactive source. The radioactive activity was 2.183 TBq. In the present calculation, the Chinese reference adult voxel phantom was used, and the Monte Carlo simulation was performed using the program based on the secondary development of Geant4 to obtain the absorbed dose of each part of the victim.Results:The dose distribution in the victim′s hands was obtained. The doses to most areas of the palm were 2-10 Gy, and the doses to the fingers were 10-20 Gy. The equivalent doses to 23 tissues or organs of the exposed person were estimated to be in the range of 0.012-0.207 Gy.Conclusions:The physical dose estimation method could evaluate rapidly the local dose distribution of the victim′s key exposed body parts, and thus provide an important reference for medical treatment.
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Objective This study intends to analyze the radioactivity level of slag and its building materials, estimate the effective dose of the residents caused by the comprehensive utilization of slag in building materials, and provide basis for rational utilization of slag. Methods Data of slag production and its comprehensive utilization in building materials, radioactive level investigation and detection of slag and building materials in different periods and regions were collected from 2005 to 2016. Using the room model of concrete structure and the model of calculating equilibrium equivalent radon concentration with the specific activity of 226Ra in indoor building materials, the external and internal radiation doses of residents caused by comprehensive utilization of slag for building materials were estimated respectively, and then the annual additional effective dose and collective dose of residents were estimated. Results The contents of 226Ra and 232Th in the slag were relatively high, while the contents of 40K were relatively low. The radionuclide content in slag cement decreased significantly. The annual additional effective doses of slag used in concrete and cement mixture relative to ordinary cement were 0.40 mSv·a−1 and 0.20 mSv·a−1 respectively. The annual additional collective dose and 50-year collective dose caused by slag used in building materials were 3.87 × 103～1.84 × 104 man·Sv and 1.94 × 105～9.20 × 105 man·Sv respectively. Conclusion The comprehensive utilization of slag in building materials increases the additional effective dose of residents, so the use of some slag in building materials needs to be paid more attention to. In addition, the influence of comprehensive utilization of slag in building materials, such as the way, the amount of slag and the amount of building materials, on the annual additional effective dose of residents caused should also be paid attention to.
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Objective@#To obtain precise data on the changes in the levels of 29 cytokines in mice after high or low linear energy transfer (LET) irradiation and to develop an accurate model of radiation exposure based on the cytokine levels after irradiation.@*Methods@#Plasma samples harvested from mice at different time points after carbon-ion or X-ray irradiation were analyzed using meso-scale discovery (MSD), a high-throughput and sensitive electrochemiluminescence measurement technique. Dose estimation equations were set up using multiple linear regression analysis.@*Results@#The relative levels of IL-6 at 1 h, IL-5 and IL-6 at 24 h, and IL-5, IL-6 and IL-15 at 7 d after irradiation with two intensities increased dose-dependently. The minimum measured levels of IL-5, IL-6 and IL-15 were up to 4.0076 pg/mL, 16.4538 pg/mL and 0.4150 pg/mL, respectively. In addition, dose estimation models were established and verified.@*Conclusions@#The MSD assay can provide more accurate data regarding the changes in the levels of the cytokines IL-5, IL-6 and IL-15. These cytokines could meet the essential criteria for radiosensitive biomarkers and can be used as radiation indicators. Our prediction models can conveniently and accurately estimate the exposure dose in irradiated organism.
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Animals , Female , Mice , Biological Assay , Biomarkers/blood , Carbon , Cytokines/blood , Heavy Ions , Linear Energy Transfer , Linear Models , Radiation Dosage , Radiation, IonizingABSTRACT
Objective To investigate the difference of size-specific dose estimates ( SSDEs ) based on effective diameter ( def ) and water equivalent diameter ( dw ) in coronary computed tomography angiography ( CCTA) and explore the causes. Methods A total of 99 patients undergoing CCTA were enrolled in this retrospective study. SSDEs ( SSDEd ef and SSDEdw ) were calculated in two approaches using def and dw , respectively. Mean absolute relative difference ( MARD) was computed as an index to quantify the consistency of SSDEd ef and SSDEdw . Multivariate stepwise regression analysis was performed to study the factors influencing MARD. Results The values def and dw were positively correlated with body mass index (BMI) (r=0. 869, 0. 823, P<0. 05). The median (interquartile range) of SSDEdef and SSDEdw were 12. 34 ( 11. 75, 12. 98) mGy, 13. 78 ( 13. 02, 15. 04) mGy, respectively. SSDEdef was lower by 10. 45％ than SSDEdw( Z=-8. 186, P<0. 05) . Both SSDEdef and SSDEdw were negatively correlated with BMI and dw(r=-0. 765, -0. 680, -0. 701, -0. 840, P<0. 05). MARD of SSDEdef and SSDEdw was generally at 11. 39％. No statistical significance was found in the correlation of MARD with BMI ( r=0. 031, P>0. 05) , however, positive correlation was shown between MARD and def ( r=0. 251, P<0. 05) , but negative correlation for MARD and dw(r=-0. 379, P<0. 05). With respect to the factors influencing MARD, four variables were included into the regression equation. MARD was positively correlated with the area of both air-filled lungs ( Arealow ) and soft tissues ( Areasoft ) (β=0. 634, 0. 102, P<0. 05) , and negatively correlated with the area of bone, enhanced cardiac chambers and aorta ( Areahigh ) and the CT value of air-filled lungs ( SIlow ) (β=-0. 234,-0. 343, P<0. 05) . Conclusions SSDEdef was approximately 10. 45％ lower than SSDEdw , which was predominantly influenced by the area of air-filled lungs due to the characteristics of low X-ray attenuation in CCTA.
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Objective To estimate the lifetime attributable risk (LAR) of lung cancer,stomach cancer,liver cancer,thyroid cancer,breast cancer and leukemia for 1-,5-and 10-year old children undergoing chest CT scan.Methods Chest CT images of children was retrieved from the picture archiving and communication system (PACS) and the average CT number and area of the region of interest (ROI) were read on the CT work station.Water equivalent diameter were calculated according to the method recommended by the American Association of Physicists in Medicine (AAPM).Furthermore,the size-specific dose estimation (SSDE) was made based on the water equivalent diameter and the volume computed tomography dose index(CTDIvol).Based on the method recommended by Caro Franck,the SSDE then was converted into average organ doses to lung,stomach,liver,thyroid,breast and blood for children at different ages and of different sex undergoing chest CT scan.On the basis of average organ dose,the cancer risk prediction model from the National Academy of Science's Biological Effects of Ionizing Radiation-Ⅶ (BEIR-Ⅶ) was used to predict the LAR for different cancers mentioned above.For lung cancer,gastric cancer,liver cancer and leukemia,the calculating sequence was from average organ dose to excess relative risk (ERR) to LAR,whereas for the thyroid cancer and breast cancer,the sequence was from ERR to average organ dose to LAR.Results The average organ dose to lung,stomach,liver,thyroid,breast and blood for children at different age and of different sex undergoing chest CT scan was obtained.The age had a statistically significant impact on the SSDE (t =24.28,P ＜ 0.05),but sex has not (P ＞ 0.05).LAR for lung cancer,gastric cancer,liver cancer,thyroid cancer,breast cancer and leukemia for 1-,5-and 10-year old children undergoing chest CT scan was obtained,among whom the LAR for thyroid cancer and breast cancer was relatively high.The LAR for women breast cancer was 10.9 per 100 000 persons for 1 year old children,30.8 per 100 000 persons for 5 years old and 34.5 per 100 000 persons for 10 years old.Conclusions With introduction of new technologies,the radiation dose due to chest CT scan is on the decline.But the induced radiation dose is still significant compared with general diagnostic radiography.The risk of cancer still deserves more attention and should be taken into consideration in the justification of diagnostic radiology.
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Objective To analyze the biological dose estimation ability of the radiation health technology institutions nationwide from 2015 to 2017,and their development in recent years.Methods SPSS 19.0 software was used to analyze and pack the data involved in the 2015-2017 year assessments by using x2 test.Statistical analysis was conducted of qualification rate,excellent rate,participating units and dose estimation deviation distribution.Results The qualification rate gradually increased from 2015 to 2017.Compared with 2015,the passing rate significantly increased in 2017 with statistically significant difference(x2 =3.978,P ＜0.05).A total of 53 units participated in the biological dose assessment,of which 30 units were involved over the three consecutive years,accounting for 57％.In the distribution of the relative deviation of dose estimates made by the units participating in the three-year assessment,the proportion of estimated deviations in the range of 5％-10％ increased whereas those in the range of 15％-20％ and ＞ 20％ decreased.Conclusions During 2015-2017 year period the biological dose estimation ability of all units involved in the assessment nationwide was basically stable,with gradually improved test level,qualification rate and steady excellence rate.
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The aim of the present study is to analyze the global research trend of radiation-responsive genes and identify the highly reproducible radiation-responsive genes. Bibliometric methods were applied to analyze the global research trend of radiation-responsive genes. We found 79 publications on radiation-responsive genes from 2000 to 2017. A total of 35 highly reproducible radiation-responsive genes were identified. Most genes are involved in response to DNA damage, cell proliferation, cell cycle regulation, and DNA repair. The p53 signal pathway was the top enriched pathway. The expression levels of 18 genes in human B lymphoblastoid cell line (AHH-1) cells were significantly up-regulated in a dose-dependent manner at 24 h after exposure to 0-5 Gy 60Co γ-ray irradiation. Our results indicate that developing a gene expression panel with the 35 high reproducibility radiation-responsive genes may be necessary for qualitative and quantitative assessment after exposure.
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Humans , Dose-Response Relationship, Radiation , Gene Expression Profiling , Gene Expression Regulation , Radiation Effects , Radiometry , Methods , Reproducibility of Results , Up-Regulation , Radiation EffectsABSTRACT
Objective To explore the natural attenuation pattern of three biological dose estimation indexes in vivo by investigating the effect on biological dosimetry of peripheral blood sampling at different time points from the victim partially exposed to 192Ir radiation source at5.7 accident in Nanjing.Methods Peripheral blood of the patient was collected on days 5,40 and 280 after exposure,respectively.The yields of dicentrics plus rings chromosomes (dic + r),cytokinesis-block micronuclei (CBMN) and nucleoplasmic bridge + fusion + horse shoe + circular(NPB + FHC) were analyzed.The dynamic reduction and dose estimation were both observed using the biomarkers mentioned above after exposure.Results Compared to the estimates on days 5 after exposure,the dose values estimated on days 40 and 280 decreased by 34％ and 49％ fordic + r method,48％ and 79％ for the CBMN assay,and 48％ and 75％ for NPN + FHC method,respectively.Conclusions Three biological dose estimation indexes show a progressive decrease in vivo,with the half-life of dic + r/cell being 40 days.The doses estimated using these three indexes on days 40 after exposure showed a relative deviation more than 20％ compared with those on days 5 after exposure.
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Objective To use three different methods in attempt to estimate the biological dose of the patient partially exposed to 192Ir source at5.7 accident in Nanjing,so as to provide dosimetric information for clinical remedy of exposed patients in the emergency of a nuclear accident.Methods Peripheral blood samples were collected on days 5 after exposure.The biological dose was estimated by the yields of dicentrics plus rings ( dic + r),cytokinesis-block micronuclei (CBMN) assay and nucleoplasmic bridge plus FHC (NPB + FHC).The homogeneity of radiation exposure was examined by Poisson distribution of dicentrics.Results By using three different methods,the whole body equivalent dose was dic + r estimated to be 1.51 Gy (95％ CI 1.40-1.61),1.47 Gy (95％ CI 1.36-1.60) by CBMN and 1.30 Gy (95％ CI 1.00-1.60) by NPB + FHC,respectively.A non-poisson distribution was also detected,suggesting partial body radiation exposure.Conclusions The estimated whole body equivalent dose ot a non-uniform radiation exposure was consistent with clinical diagnosis,suggesting that the yields ofdic + r,CBMN,as well as NPB + FHC,are efficient approaches to the estimation of biological doses.
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Objective To make a rapid dose estimation for a patient exposed locally to high dose radiation exposure in early stage of 5.7 192Ir source accident in Nanjing.Methods Based on source parameters,exposure pattern,and time duration,the doses were estimated using MCNP simulations with the aid of the proper East Asia adult male voxel phantom and main physiological parameters of the exposed patient.Result Absorbed doses to 16 organs or tissues were estimated to be in the range 0.03 to 9.16 Gy.Also,the iso-dose curves for the skin of legs showed clearly the dose difference between right and left legs.Absorbed doses to patient's testicles and prostrate,about 9.16 Gy,were higher than those to other organs or tissues.The skin of both legs was exposed locally to high dose radiation exposure,for which the estimated doses were in agreement with the results obtained from infrared thermal imaging.Conclusions Monte Carlo simulation technique and common software can be used for dose estimation in early stage of radiation accidents effectively with integrating proper models.