Objective:To investigate the radioactivity levels and variation trends of 90Sr in drinking water and food around the Qinshan Nuclear Power Plant in operation. Methods:From 2012 to 2022, the source, factory, and tap water was collected within 30 km around the Qinshan Nuclear Power Plant during the wet and dry seasons (i.e., May and October, respectively) each year to determine the 90Sr concentration in water. According to the dietary habits of local residents, four kinds of food, including rice, cabbage, mullet, and crucian carp, were collected to determine and analyze the 90Sr radioactivity concentration in food using the bis-(2-ethylhexyl) phosphoric acid extraction chromatographic method. Results:From 2012 to 2022, the 90Sr radioactivity concentrations in the source, factory, and tap water around the Qinshan Nuclear Power Plant ranged from 3.73 to 11.89 mBq/L, 2.95 to 9.83 mBq/L, and 3.12 to 8.70 mBq/L, respectively, showing nonsignificant fluctuations over the years. The 90Sr radioactivity concentrations in rice, cabbage, mullet, and crucian carp ranged from 0.02 to 0.46 Bq/kg (dry weight), 0.26 to 1.07 Bq/kg (fresh weight), 0.38 to 1.05 Bq/kg (fresh weight), and 0.08 to 1.32 Bq/kg (fresh weight), respectively, all below the national standard limits. Conclusions:From 2012 to 2022, the 90Sr radioactivity levels in drinking water and food around the Qinshan Nuclear Power Plant were at the background level and remained stable.

Objective:To investigate the current situation of nuclear medicine practices, determine the number of nuclear medicine staff, conduct internal exposure monitoring and dose estimation for nuclear mecidine staff engaged in 131I treatment in Zhejiang province. Methods:A survey was conducted over all the 22 hospitals involved in 131I treatment in the province. The 131I activity in thyroid of 96 stafff in 131I treatment workplaces were measured by means of direct method. At the same time, the effective doses from internal exposure were estimated and the influencing factors were analyzed. Results:131I activity in thyroids was found to be above the detection limit for 49 staff (51.04%) in nineteen hospitals. The maximum value of 131I activity was 629.18 Bq. There was no statistically significant difference in 131I detection rate in thyroid of 131I treatment staff between different positions, different genders and different levels of hospitals ( P>0.05). Comparisons of 131I activity of thyroid of nuclear medicine staff for theatment of thyroid cancers had shown that the highest was for nurses, followed by technicians and doctors, and the lowest was for cleaning staff ( H=6.39, P<0.05). The estimated committed effective dose to the nuclear medicine staff ranged from 0.05 to 2.37 mSv, with those below 1 mSv accounting for 93.88% of the total. Logistic regression analysis showed that nursing position was the risk factor contributing to the committed effective dose ( OR=2.805, 95% CI 1.076-7.314). Conclusions:In Zhejiang province, the committed effective dose to thyroid of nuclear medicine staff from 131I internal exposure was not in excess of the dose limit. However, the staff performing iodine therapy still need to strengthen protection against internal exposure and take scientific and effective protective measures to reduce the risk of health hazards from internal exposure.

To promote the development of radiological health by means of high quality and efficient quality control measures is worthy of further discussion and practice. There are 34 radiological health technical service institutions (including 11 Grade A ones), 36 occupational health examination institutions for radiation workers, and 4 radiation disease diagnosis institutions in Zhejiang province. Zhejiang Provincial Health Commission approved the establishment of Zhejiang Provincial Radiological Health Technical Service Quality Control Center and Zhejiang Provincial Occupational Health Technical Service Quality Control Center in 2012 and 2021, respectively, both under the leadship of Zhejiang Provincial Center for Disease Prevention and Control. Through constructing a multi-dimensional closed-loop quality control system, a great progress has been made in efforts in radiological health of Zhejiang province.

Objective:To investigate the radioactivity levels and variation trends of 90Sr in drinking water and food around the Qinshan Nuclear Power Plant in operation. Methods:From 2012 to 2022, the source, factory, and tap water was collected within 30 km around the Qinshan Nuclear Power Plant during the wet and dry seasons (i.e., May and October, respectively) each year to determine the 90Sr concentration in water. According to the dietary habits of local residents, four kinds of food, including rice, cabbage, mullet, and crucian carp, were collected to determine and analyze the 90Sr radioactivity concentration in food using the bis-(2-ethylhexyl) phosphoric acid extraction chromatographic method. Results:From 2012 to 2022, the 90Sr radioactivity concentrations in the source, factory, and tap water around the Qinshan Nuclear Power Plant ranged from 3.73 to 11.89 mBq/L, 2.95 to 9.83 mBq/L, and 3.12 to 8.70 mBq/L, respectively, showing nonsignificant fluctuations over the years. The 90Sr radioactivity concentrations in rice, cabbage, mullet, and crucian carp ranged from 0.02 to 0.46 Bq/kg (dry weight), 0.26 to 1.07 Bq/kg (fresh weight), 0.38 to 1.05 Bq/kg (fresh weight), and 0.08 to 1.32 Bq/kg (fresh weight), respectively, all below the national standard limits. Conclusions:From 2012 to 2022, the 90Sr radioactivity levels in drinking water and food around the Qinshan Nuclear Power Plant were at the background level and remained stable.

Objective:To investigate the current situation of nuclear medicine practices, determine the number of nuclear medicine staff, conduct internal exposure monitoring and dose estimation for nuclear mecidine staff engaged in 131I treatment in Zhejiang province. Methods:A survey was conducted over all the 22 hospitals involved in 131I treatment in the province. The 131I activity in thyroid of 96 stafff in 131I treatment workplaces were measured by means of direct method. At the same time, the effective doses from internal exposure were estimated and the influencing factors were analyzed. Results:131I activity in thyroids was found to be above the detection limit for 49 staff (51.04%) in nineteen hospitals. The maximum value of 131I activity was 629.18 Bq. There was no statistically significant difference in 131I detection rate in thyroid of 131I treatment staff between different positions, different genders and different levels of hospitals ( P>0.05). Comparisons of 131I activity of thyroid of nuclear medicine staff for theatment of thyroid cancers had shown that the highest was for nurses, followed by technicians and doctors, and the lowest was for cleaning staff ( H=6.39, P<0.05). The estimated committed effective dose to the nuclear medicine staff ranged from 0.05 to 2.37 mSv, with those below 1 mSv accounting for 93.88% of the total. Logistic regression analysis showed that nursing position was the risk factor contributing to the committed effective dose ( OR=2.805, 95% CI 1.076-7.314). Conclusions:In Zhejiang province, the committed effective dose to thyroid of nuclear medicine staff from 131I internal exposure was not in excess of the dose limit. However, the staff performing iodine therapy still need to strengthen protection against internal exposure and take scientific and effective protective measures to reduce the risk of health hazards from internal exposure.

To promote the development of radiological health by means of high quality and efficient quality control measures is worthy of further discussion and practice. There are 34 radiological health technical service institutions (including 11 Grade A ones), 36 occupational health examination institutions for radiation workers, and 4 radiation disease diagnosis institutions in Zhejiang province. Zhejiang Provincial Health Commission approved the establishment of Zhejiang Provincial Radiological Health Technical Service Quality Control Center and Zhejiang Provincial Occupational Health Technical Service Quality Control Center in 2012 and 2021, respectively, both under the leadship of Zhejiang Provincial Center for Disease Prevention and Control. Through constructing a multi-dimensional closed-loop quality control system, a great progress has been made in efforts in radiological health of Zhejiang province.

Objective:To improve the dosimetric accuracy of cell irradiation experiments by developing a method of accurately measuring the absorbed dose of ultra-thin solution in culture dishes under 200 kV medium-energy X-rays using EBT3 films.Methods:EBT3 film dose calibration was performed under Cyberknife 6 MV beam, and the beam quality (half-value layer) and effective energy of the 200 kV beam used in this study generated from Small Animal Radiation Research Platform through measurements and calculations were obtained to determine the EBT3 energy response correction factor. The 200 kV beam was utilized to irradiate three commonly used culture dishes filled with ultra-thin liquid placed on EBT3 films and the corrected EBT3 doses were taken as the liquid absorbed doses. The dose linearity of immersed films was also measured and analyzed. In addition, after modeling the irradiation environment, the independent Monte Carlo calculations of the liquid absorbed dose were performed by MCNP5 program. The calculation results were compared with the film measurement results to verify the accuracy of the measured doses.Results:The 200 kV beam had a half-value layer of 8.77 mm aluminum and effective energy of 57.4 keV, corresponding to an energy response correction factor of 0.889. The average liquid absorbed doses of large, medium and small culture dishes measured by EBT3 films under the specified parameters of 200 kV beam were (1.434±0.004) Gy, (1.467±0.011) Gy and (1.469±0.027) Gy after correction, respectively. The percentage errors from the corresponding Monte Carlo calculation doses were 0.07%, -0.70%, and 0.47%, respectively, where the relatively consistent results could be found. In addition, the dose linearity of immersed EBT3 films was also good, with coefficient of determination R2=0.9972. Conclusion:The method of measuring the dose of ultra-thin cell solution using EBT3 films proposed in this study is feasible, and the dose results obtained yield high accuracy under 200 kV beam.

Objective To investigate the current situation of occupational health of radiation workers in Zhejiang Province, China, and to provide a theoretical basis for the improvement of standards and management systems for occupational health examinations of radiation workers. Methods Data of occupational health examination cases were collected from occupational health examination institutions, including basic information, type of physical examination (pre-job, on-job, off-job), and health examination results. The differences in occupational health examination results among different groups were analyzed, and the factors influencing occupational health of radiation workers were analyzed using a logistic regression model. Results A total of 5668 cases were collected, with 86% of the participants being male and 14% being female. Compared with the pre-job group, the on-job group showed an increased abnormal rate of triiodothyronine and the off-job group demonstrated an increased abnormal rate of leukocyte count (P < 0.05). Compared with the industrial group, the nuclear fuel group showed decreased abnormal rates of thyroid structure and thyroxine and an increased abnormal rate of triiodothyronine, and the medical group demonstrated an increased abnormal rate of thyroid structure (P < 0.05). The abnormal rates of thyroid structure and white blood cell count increased with the increase of working age (P < 0.05). The abnormal rates of white blood cell count, thyroid structure, triiodothyronine, and thyroid stimulating hormone were higher in female radiation workers than in male radiation workers (P < 0.05). Sex (female), radiation work history, and age were the risk factors affecting the occupational health of radiation workers (P < 0.05). Conclusion The occupational health status of radiological workers in Zhejiang Province needs to be further improved, and the occupational health management of radiological workers should be strengthened.

Objective To investigate the current situation of occupational health of radiation workers in Zhejiang Province, China, and to provide a theoretical basis for the improvement of standards and management systems for occupational health examinations of radiation workers. Methods Data of occupational health examination cases were collected from occupational health examination institutions, including basic information, type of physical examination (pre-job, on-job, off-job), and health examination results. The differences in occupational health examination results among different groups were analyzed, and the factors influencing occupational health of radiation workers were analyzed using a logistic regression model. Results A total of 5668 cases were collected, with 86% of the participants being male and 14% being female. Compared with the pre-job group, the on-job group showed an increased abnormal rate of triiodothyronine and the off-job group demonstrated an increased abnormal rate of leukocyte count (P < 0.05). Compared with the industrial group, the nuclear fuel group showed decreased abnormal rates of thyroid structure and thyroxine and an increased abnormal rate of triiodothyronine, and the medical group demonstrated an increased abnormal rate of thyroid structure (P < 0.05). The abnormal rates of thyroid structure and white blood cell count increased with the increase of working age (P < 0.05). The abnormal rates of white blood cell count, thyroid structure, triiodothyronine, and thyroid stimulating hormone were higher in female radiation workers than in male radiation workers (P < 0.05). Sex (female), radiation work history, and age were the risk factors affecting the occupational health of radiation workers (P < 0.05). Conclusion The occupational health status of radiological workers in Zhejiang Province needs to be further improved, and the occupational health management of radiological workers should be strengthened.

Background Excessive radon exposure is considered the second risk factor for lung cancer. Since the opening of the subway in a city of Zhejiang Province, the exposure level of radioactive gas radon in subway stations and its impact on occupational health have become one of the important issues of public concern. Objective To monitor the radon concentration of subways in a city in Zhejiang Province and explore the effect of radon exposure on chromosome aberration and micronuclei in the working population. Methods A total of 55 vehicle control rooms of 55 stations affiliated to two different subway lines in a city were measured for one year; the 110 ticket offices and 55 security checkpoints from the same 55 stations were measured from 16 March to 14 June. The radon concentrations were compared by job types, subway lines, and seasons referring to Measurement methods for determination of radon in environmental air (HJ 1212-2021). Peripheral blood lymphocyte chromosome aberration and micronucleus analyses were conducted in 165 subway workers from monitoring sites for three different job types, then the influencing factors were analyzed. The detection methods were adopted from the standards of Test and assessment of chromosomal aberrations on occupational health examinations for radiation workers (GBZ/T 248-2014) and Standard for the method of micronucleus detection in lymphocytes on occupational health examination for radiation workers and exposure dose estimation (GBZ/T 328-2023). Results The radon concentration range of the target subways in Zhejiang Province was 10-320 Bq·m⁻³, all lower than the national limit (≤400 Bq·m⁻³). The differences in radon radioactivity levels among different lines, job types, and time segments were statistically significant (P<0.05). The rates of chromosomal aberration and micronucleus formation among the 165 subjects were 0.224% and 0.024%, respectively. There were significant differences in the rates of chromosome aberration and micronuclei among different jobs (vehicle control room, ticket office, security checkpoint) (P<0.05), but the abnormal rates were lower than the limits of the corresponding national standard. No significant correlation was found between jobs and chromosomal aberrations or micronuclei (P>0.05). Chromosome aberration and micronuclei varied by age, subway station seniority, and smoking (P<0.05). No effect of the above factors on chromosome aberration and micronuclei was observed by logistic regression (P>0.05). Conclusion The radon concentration in the target subway system is at a normal level. The rates of chromosomal aberration and micronucleus formation vary by jobs, but both are lower than the corresponding national limits. Therefore, radon exposure has not yet caused outstanding health impact on the subway workers.