2023 Vol. 47, No. 10
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2023, 47(10): 589-592.
doi: 10.3760/cma.j.cn121381-202309026-00361
Abstract:
Tritium is the main raw material for nuclear fusion reaction, strengthening the research on the impact of tritium on the environment, the harm to living organisms and the radiation protection system has become an urgent issue. This paper mainly introduces the hazard and evaluation of tritium, tritium protection and management, and proposes the main issues of further tritium research.
Tritium is the main raw material for nuclear fusion reaction, strengthening the research on the impact of tritium on the environment, the harm to living organisms and the radiation protection system has become an urgent issue. This paper mainly introduces the hazard and evaluation of tritium, tritium protection and management, and proposes the main issues of further tritium research.
2023, 47(10): 593-601.
doi: 10.3760/cma.j.cn121381-202308027-00350
Abstract:
Objective To study the effects of long-term tritiated water exposure on the growth and development of zebrafish offspring. Methods Embryos produced by wild-type AB strain zebrafish were exposed to 0, 1×102, and 1×105 Bq/L tritiated water for long-term feeding as parents (F0 generation). After their sexual maturity, they reproduced, and the offspring obtained were recorded as F1 generation. The F1 generation zebrafish continued to be raised in tritiated water concentrations corresponding to the F0 generation. We observed the growth and development of F1 generation zebrafish and detected autonomous movement and heart rate during the embryonic stage; hatching rate, body length, and reactive oxygen species (ROS) fluorescence intensity during the seedling stage; total superoxide dismutase (T-SOD), malondialdehyde (MDA), and total tritium contents during the juvenile stage; and egg production during the adult stage. The t-test was used for intergroup comparison of various detection indicators(equal variance). Results The hatching rates of the three groups of zebrafish in F1 generation were (90.66±0.05)%, (85.63±0.10)%, and (78.06±0.15)%. Compared with the 0 Bq/L tritiated water exposure group, no statistically significant difference was found in the hatching rate of F1 zebrafish between the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.785, 1.370; P=0.462, 0.220). The number of autonomous movement of the three groups of zebrafish in F1 generation at 24 h after fertilization was (12.93±2.70), (11.30±0.78), and (10.50±0.80) times/min. Compared with the 0 Bq/L tritiated water exposure group, we observed no statistically significant difference in the number of autonomous movements of F1 generation zebrafish at 24 h after fertilization in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=1.008, 1.499; P=0.370, 0.208). The number of autonomous movement of the three groups of zebrafish at 36 h after fertilization was (3.63±1.43), (4.50±1.15), and (5.40±3.55) times/min. Compared with the 0 Bq/L tritiated water exposure group, we found no statistically significant difference in the number of autonomous movement of F1 generation zebrafish at 36 h after fertilization in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.817, 0.799; P=0.460, 0.469). The heart rates of the three groups of zebrafish at 48 h after fertilization were (59.43±6.93), (65.00±3.30), and (61.23±4.55) times/20 s. Compared with the 0 Bq/L tritiated water exposure group, we observed no statistically significant difference in the heart rate of F1 generation zebrafish at 48 h after fertilization in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=1.256, 0.376; P=0.278, 0.726). The heart rates of the three groups of zebrafish at 60 h after fertilization were (69.87±2.71), (66.17±6.97), and (69.77±9.08) times/20 s. Compared with the 0 Bq/L tritiated water exposure group, we found no statistically significant difference in the heart rate of F1 generation zebrafish at 60 h after fertilization in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.857, 0.018; P=0.440, 0.986).The body lengths of the three groups of zebrafish at 72 h after fertilization were (3.20±0.22), (3.32±0.08), and (3.29±0.06) mm. Compared with the 0 Bq/L tritiated water exposure group, no statistically significant difference was noted in the body length of F1 generation zebrafish at 72 h after fertilization in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.614, 0.178; P=0.525, 0.868). The body length of the three groups of zebrafish at 84 h after fertilization were (3.42±0.07), (3.46±0.11), and (3.40±0.04) mm. Compared with the 0 Bq/L tritiated water exposure group, no statistically significant difference was observed in the body length of F1 generation zebrafish at 84 h after fertilization in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.527, 0.496; P=0.626, 0.646). The ROS fluorescence intensities of the three groups of zebrafish in F1 generation were (21.07±4.74), (23.71±7.73), and (23.19±5.32), respectively. Compared with the 0 Bq/L tritiated water exposure group, there was no statistically significant difference in ROS fluorescence intensity of F1 generation zebrafish seedlings in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.582, 0.593; P=0.582, 0.575). The T-SOD contents of the three groups of zebrafish in F1 generation at 45 days were (41.84±4.91), (42.30±5.04), and (36.97±5.26) U/mgprot. Compared with the 0 Bq/L tritiated water exposure group, we found no statistically significant difference in the T-SOD content of F1 generation zebrafish at 45 days in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.112, 1.171; P=0.916, 0.307).The T-SOD contents of three groups of zebrafish at 60 days were (36.93±1.91), (34.07±3.02), and (33.54±1.87) U/mgprot. Compared with the 0 Bq/L tritiated water exposure group, there was no statistically significant difference in the T-SOD content of F1 generation zebrafish at 60 days in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=1.397, 2.195; P=0.240, 0.093). The MDA contents of the three groups of zebrafish at 45 days were (3.60±1.56), (3.59±0.44), and (2.95±0.58) nmol/mgprot. Compared with the 0 Bq/L tritiated water exposure group, we found no statistically significant difference in the MDA content of F1 generation zebrafish at 45 days in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.007, 0.677; P=0.995, 0.536). The MDA contents of the three groups of zebrafish at 60 days were (4.00±0.52), (4.19±1.37), and (3.01±0.32) nmol/mgprot. Compared with the 0 Bq/L tritiated water exposure group, there was no statistically significant difference in the MDA content in F1 generation zebrafish at 60 days in the 1×102 Bq/L tritiated water (t=0.229, P=0.830); the difference in the MDA content in F1 generation zebrafish exposed to 1×105 Bq/L tritiated water was statistically significant (t=2.831, P=0.047). The eggs laid by the three groups of zebrafish in F1 generation were 188±88, 204±22, and 220±40. Compared with the 0 Bq/L tritiated water exposure group, we found no statistically significant difference in the egg production of F1 generation zebrafish in the 1×102 Bq/L and 1×105 Bq/L tritiated water exposure groups (t=0.400, 0.757; P=0.700, 0.477). The tritium content in the body of F1 generation zebrafish was (32.23±1.97) Bq/g at 60 days. Conclusion Long-term exposure to 1×105 Bq/L tritiated water can lead to the accumulation of tritium in F1 generation zebrafish.
2023, 47(10): 602-607.
doi: 10.3760/cma.j.cn121381-202308028-00351
Abstract:
Objective To study the effect of tritium water radiation dose on zebrafish at early developmental stages and integration with biological effects for the preliminary observation of dose–effect relationships. Methods The real experimental conditions were simulated, the physical conditions were modeled, and the absorbed dose rates were calculated for 24 hours post fertilization (hpf）embryos and 96 hpf larvae in three different concentrations of tritium water: 3.7×103, 3.7×104, and 3.7×105 Bq/ml. The embryos or larvae turnover frequency and heart rate of 24 and 96 hpf were observed and compared with those of the control group. Comparisons between multiple groups were analyzed by one-way ANOVA, and differences between the control and treatment groups were compared for significance using the LSD-t test. Results With the extension of development time, the absorbed dose of zebrafish increased in three different concentrations of tritiated water. 24 hpf embryos corresponding to dose rates of 2.15×10, 2.21×102, 2.55×103 μGy/h; 96 hpf larvae corresponding to dose rates of 2.95×10, 3.03×102, 3.47×103 μGy/h. Comparison with control group, the results of 24 hpf embryo flipping showed that the significantly fewer embryos turned over in the tritium water-stained group whith 3.7×103 Bq/ml( t=3.94, P＜0.001); and 96 hpf larvae heart rate changes significantly with tritium water concentration. Comparison with control group, the 3.7×103 Bq/ml tritium water-treated group had a significant decrease in heart rate(t=2.86, P=0.01), while the 3.7×105 Bq/ml tritium water-treated group had an increase in heart rate (t=−12.12, P<0.001). Conclusion Significant changes in embryonic turnover at 24 hpf and heart rate of larvae at 96 hpf were observed with changes in absorbed dose rate.
2023, 47(10): 608-614.
doi: 10.3760/cma.j.cn121381-202309011-00366
Abstract:
Studies on the relative biological effectiveness (RBE) of tritium as nuclear fusion fuel under low-dose irradiation from the perspective of radiation protection were summarized. Two tritium irradiation methods, namely, exponentially decreasing dose rate and constant dose rate, were selected to observe and analyze the following biological indicators: dominant lethal mutation rate in oocytes and spermatocytes, dominant skeletal mutation rate, survival rate of primary oocytes and spermatogonia, and micronucleus cell rate in peripheral blood lymphocytes and polychromatic erythrocytes of fetal liver. The RBE under these two tritium irradiation methods was calculated, and the factors influencing the RBE were analyzed. Results showed that at cumulative doses of 0.2, 0.3, 0.4, 0.5, and 0.6 Gy/10 d, the RBE under the tritium irradiation methods of exponentially decreasing dose rate and constant dose rate was 2.9–4.2. For radiation protection, the RBE of low-linear energy transfer (LET) radiation on the biome must be set to 3.0–3.5. In case of exposure to tritium β particles or other low-LET radiation or values close to the derived reference level, a high RBE may be required for an accurate estimation of the radiation risk.
Studies on the relative biological effectiveness (RBE) of tritium as nuclear fusion fuel under low-dose irradiation from the perspective of radiation protection were summarized. Two tritium irradiation methods, namely, exponentially decreasing dose rate and constant dose rate, were selected to observe and analyze the following biological indicators: dominant lethal mutation rate in oocytes and spermatocytes, dominant skeletal mutation rate, survival rate of primary oocytes and spermatogonia, and micronucleus cell rate in peripheral blood lymphocytes and polychromatic erythrocytes of fetal liver. The RBE under these two tritium irradiation methods was calculated, and the factors influencing the RBE were analyzed. Results showed that at cumulative doses of 0.2, 0.3, 0.4, 0.5, and 0.6 Gy/10 d, the RBE under the tritium irradiation methods of exponentially decreasing dose rate and constant dose rate was 2.9–4.2. For radiation protection, the RBE of low-linear energy transfer (LET) radiation on the biome must be set to 3.0–3.5. In case of exposure to tritium β particles or other low-LET radiation or values close to the derived reference level, a high RBE may be required for an accurate estimation of the radiation risk.
2023, 47(10): 615-625.
doi: 10.3760/cma.j.cn121381-202309012-00367
Abstract:
The study of the effects of ionizing radiation on the developing central nervous system and the underlying mechanisms is an important subject for the International Commission on Radiological Protection and United Nations Scientific Committee on the Effects of Atomic Radiation. Results from epidemiological investigations on A-bomb survivors are the main basis for evaluating radiation risk. However, given that these results reflect the biological effects of high-dose-rate single acute exposure, they cannot accurately reflect the biological effects of tritium beta particles under low-dose-rate continuous exposure. Radiation sensitivity of the central nervous system changes with its developmental stage, resulting in different radiation risks under various exposure situations. This paper reviews the achievements obtained in a series of comprehensive studies led by Dr. Zhou's research group of the former Laboratory of Industrial Hygiene, Ministry of Public Health (now National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention) from the 1980s to the present. Researchers used a total of 56 biological endpoints as evaluation indicators for physiological development, neurobehavior, brain pathology, and neurobiochemistry in prenatally exposed offspring, as well as electrophysiology, morphological, and biochemical changes in brain cells in primary cultures, comprehensively explored the effects and mechanisms of low-dose tritium β particles intrauterine irradiation on the developing central nervous system from multiple levels. This work is the first time to use the same experimental systems, from molecules, cells, and organs to the whole body, from tissue structure, neurobiochemistry, and behavior to learning and memory functions, to evaluate the risk of continuous low-dose tritium beta particle exposure on the developing central nervous system. These important achievements provide the most reliable and authoritative scientific basis for comprehensively and systematically evaluating the radiation risk of tritium beta particles on the developing central nervous system.
The study of the effects of ionizing radiation on the developing central nervous system and the underlying mechanisms is an important subject for the International Commission on Radiological Protection and United Nations Scientific Committee on the Effects of Atomic Radiation. Results from epidemiological investigations on A-bomb survivors are the main basis for evaluating radiation risk. However, given that these results reflect the biological effects of high-dose-rate single acute exposure, they cannot accurately reflect the biological effects of tritium beta particles under low-dose-rate continuous exposure. Radiation sensitivity of the central nervous system changes with its developmental stage, resulting in different radiation risks under various exposure situations. This paper reviews the achievements obtained in a series of comprehensive studies led by Dr. Zhou's research group of the former Laboratory of Industrial Hygiene, Ministry of Public Health (now National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention) from the 1980s to the present. Researchers used a total of 56 biological endpoints as evaluation indicators for physiological development, neurobehavior, brain pathology, and neurobiochemistry in prenatally exposed offspring, as well as electrophysiology, morphological, and biochemical changes in brain cells in primary cultures, comprehensively explored the effects and mechanisms of low-dose tritium β particles intrauterine irradiation on the developing central nervous system from multiple levels. This work is the first time to use the same experimental systems, from molecules, cells, and organs to the whole body, from tissue structure, neurobiochemistry, and behavior to learning and memory functions, to evaluate the risk of continuous low-dose tritium beta particle exposure on the developing central nervous system. These important achievements provide the most reliable and authoritative scientific basis for comprehensively and systematically evaluating the radiation risk of tritium beta particles on the developing central nervous system.
2023, 47(10): 626-631.
doi: 10.3760/cma.j.cn121381-202308004-00353
Abstract:
In recent years, the radiation effects of tritium have received widespread attention. Medical emergency to tritium-related accidents is a task with high requirements for specialized technology, wide coverage and wide impact. China's nuclear and radiation-related laws and regulations for emergency have a perfect emergency system and rescue management program. The author combines the characteristics of tritium radiation accidents and the relevant provisions of laws and regulations to analyze the three-level rescue system for medical emergency to tritium accidents, the medical management of tritium accidents and the psychological assistance of the illuminated personnel, etc., in order to put forward constructive opinions for the medical emergency and management of tritium-related accidents.
In recent years, the radiation effects of tritium have received widespread attention. Medical emergency to tritium-related accidents is a task with high requirements for specialized technology, wide coverage and wide impact. China's nuclear and radiation-related laws and regulations for emergency have a perfect emergency system and rescue management program. The author combines the characteristics of tritium radiation accidents and the relevant provisions of laws and regulations to analyze the three-level rescue system for medical emergency to tritium accidents, the medical management of tritium accidents and the psychological assistance of the illuminated personnel, etc., in order to put forward constructive opinions for the medical emergency and management of tritium-related accidents.
2023, 47(10): 632-637.
doi: 10.3760/cma.j.cn121381-202308006-00354
Abstract:
Tritium, a radionuclide, can enter the human body through various pathways, including the digestive tract, respiratory tract, skin surface and wounds, resulting in varying degrees of internal radiation damage to human health. In this paper, the characteristics, absorption and metabolism of tritium are briefly introduced, and the clinical medical treatment data of internal tritium contamination caused by several accidents at home and abroad are reviewed. The key points of treatment and enlightenment for internal tritium contamination are put forward.
Tritium, a radionuclide, can enter the human body through various pathways, including the digestive tract, respiratory tract, skin surface and wounds, resulting in varying degrees of internal radiation damage to human health. In this paper, the characteristics, absorption and metabolism of tritium are briefly introduced, and the clinical medical treatment data of internal tritium contamination caused by several accidents at home and abroad are reviewed. The key points of treatment and enlightenment for internal tritium contamination are put forward.
2023, 47(10): 638-641.
doi: 10.3760/cma.j.cn121381-202309016-00362
Abstract:
Tritium-labeled compounds are widely used in the field of medicine, especially tritium-labeled biomolecules, which can be used to analyze the metabolic processes of various molecules inside and within cells. This article introduces the synthesis methods of tritium-labeled compounds, provides an overview of the achievements and research progress of tritium-labeled biomolecules in the field of radiobiology and medical applications, with a focus on explaining the principles and applications of tritium-labeled thymidine nucleosides in determining DNA synthesis efficiency. Tritium-labeled compounds offer the advantages of simplicity, speed, intuitiveness, and accuracy in studying the distribution and metabolic processes of molecules such as DNA, RNA, and proteins within cells. Further development of analytical methods based on tritium-labeled compounds is of significant importance for a deeper understanding of molecular biology mechanisms.
Tritium-labeled compounds are widely used in the field of medicine, especially tritium-labeled biomolecules, which can be used to analyze the metabolic processes of various molecules inside and within cells. This article introduces the synthesis methods of tritium-labeled compounds, provides an overview of the achievements and research progress of tritium-labeled biomolecules in the field of radiobiology and medical applications, with a focus on explaining the principles and applications of tritium-labeled thymidine nucleosides in determining DNA synthesis efficiency. Tritium-labeled compounds offer the advantages of simplicity, speed, intuitiveness, and accuracy in studying the distribution and metabolic processes of molecules such as DNA, RNA, and proteins within cells. Further development of analytical methods based on tritium-labeled compounds is of significant importance for a deeper understanding of molecular biology mechanisms.
2023, 47(10): 642-646.
doi: 10.3760/cma.j.cn121381-202309034-00365
Abstract:
Nuclear energy is an indispensable energy for human beings in the development of the world economy. Both the tritium produced in nuclear fission reactors and the fuel tritium adopted in nuclear fusion reactors are at risk of leakage and release. Therefore, the transfer and monitoring of tritium in the aerosphere, hydrosphere, pedosphere and biosphere is a pioneering and important topic in the field of radiation protection. This paper reviewed the classification of nuclear fusion energy, the source and transfer of fuel tritium in nuclear fusion, the monitoring of tritium in air, the analysis of tritium in water, the monitoring of tritium in soil, the analysis of tritium in food and biological samples, and the monitoring of tritium level in the environment, which can provide important reference for the healthy development of nuclear energy and tritium monitoring.
Nuclear energy is an indispensable energy for human beings in the development of the world economy. Both the tritium produced in nuclear fission reactors and the fuel tritium adopted in nuclear fusion reactors are at risk of leakage and release. Therefore, the transfer and monitoring of tritium in the aerosphere, hydrosphere, pedosphere and biosphere is a pioneering and important topic in the field of radiation protection. This paper reviewed the classification of nuclear fusion energy, the source and transfer of fuel tritium in nuclear fusion, the monitoring of tritium in air, the analysis of tritium in water, the monitoring of tritium in soil, the analysis of tritium in food and biological samples, and the monitoring of tritium level in the environment, which can provide important reference for the healthy development of nuclear energy and tritium monitoring.
2023, 47(10): 647-651.
doi: 10.3760/cma.j.cn121381-202308017-00352
Abstract:
Tritium is one of the common radioisotopes in the nuclear power plant. In heavy water reactors, tritium causes the higher internal exposure because of the reactor design. Third Qinshan Nuclear Power Plant (TQNPP) is the only heavy-water-reactor nuclear power plant in China, which has 2 CANDU6 reactors. Since TQNPP were put into commercial operation in 2003, TQNPP strictly performs area and individual tritium radiation monitoring, continuously improves monitoring techniques and personnel protection methods for tritium internal exposure, ensuring the occupational safety and healthy of plant staffs. From 2003–2022, none of incident caused by tritium internal exposure which the effective dose is above the regulatory limits was occurred, the average individual annual tritium internal effective dose is lower than 200 μSv, and the percentage of the average annual tritium internal exposure collective dose is 18.6%, which is lower than the average level of 20%–30% around the global heavy water reactor plants, showing that the management practice of tritium internal exposure monitoring and protection in TQNPP is effective.
Tritium is one of the common radioisotopes in the nuclear power plant. In heavy water reactors, tritium causes the higher internal exposure because of the reactor design. Third Qinshan Nuclear Power Plant (TQNPP) is the only heavy-water-reactor nuclear power plant in China, which has 2 CANDU6 reactors. Since TQNPP were put into commercial operation in 2003, TQNPP strictly performs area and individual tritium radiation monitoring, continuously improves monitoring techniques and personnel protection methods for tritium internal exposure, ensuring the occupational safety and healthy of plant staffs. From 2003–2022, none of incident caused by tritium internal exposure which the effective dose is above the regulatory limits was occurred, the average individual annual tritium internal effective dose is lower than 200 μSv, and the percentage of the average annual tritium internal exposure collective dose is 18.6%, which is lower than the average level of 20%–30% around the global heavy water reactor plants, showing that the management practice of tritium internal exposure monitoring and protection in TQNPP is effective.
2023, 47(10): 652-658.
doi: 10.3760/cma.j.cn121381-202308005-00356
Abstract:
The promotion and application of nuclear fusion is an important national energy strategy. Tritium emissions into the environment have increased, and its application in many fields has become extensive. Accordingly, the probability of human exposure to low-dose tritium radiation also increases. In 2021, International Commission on Radiological Protection (ICRP) Publication 148: Radiation Weighting for Reference Animals and Plants was officially released. Among the selected materials, relevant literature from Chinese scholars and results of research on tritium relative biological efficiency (RBE) are cited. Based on ICRP Publication 148, the author summarizes the RBE values of the effects of low-energy tritium β particles on different biological endpoints, as well as the contributions made by Chinese scholars to tritium research. We further discuss prospects for future research on tritium to promote its in-depth study and suitably contribute to its radiation protection.
The promotion and application of nuclear fusion is an important national energy strategy. Tritium emissions into the environment have increased, and its application in many fields has become extensive. Accordingly, the probability of human exposure to low-dose tritium radiation also increases. In 2021, International Commission on Radiological Protection (ICRP) Publication 148: Radiation Weighting for Reference Animals and Plants was officially released. Among the selected materials, relevant literature from Chinese scholars and results of research on tritium relative biological efficiency (RBE) are cited. Based on ICRP Publication 148, the author summarizes the RBE values of the effects of low-energy tritium β particles on different biological endpoints, as well as the contributions made by Chinese scholars to tritium research. We further discuss prospects for future research on tritium to promote its in-depth study and suitably contribute to its radiation protection.
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