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Objective To analyze the occupational hazards and protective measures for personnel in an iodine-125(125I) seed source production company. Methods In 2022, a 125I seed source production enterprise in Guangdong Province was selected as the research subject. The occupational hazards in the workplace of the research subject was identified using the system engineering analysis method. The FLUAK program based on Monte Carlo method was used to simulate the blocking protection of the production of the 125I seed source, and to estimate the dose of internal and external irradiation of seed source that affected workers. Results The main occupational radiation hazards in the seed production were non-sealed radioactive materials, including external irradiation from X-ray and γ ray and internal irradiation from aerosols formed by iodine volatilization. Estimated maximum dose equivalent rate around the chest and eye lens for workers were 0.52 and 0.02 μSv/h, respectively. The expected annual effective dose for workers in each work site was 0.035 mSv, and the expected annual equivalent dose to the eye lens for all workers in various work sites was 0.001 mSv. The maximum annual equivalent dose of operator's hand was 80.620 mSv. The maximum dose of internal irradiation to the worker was 18.750 mSv, which was caused by the volatilization of nuclides. Conclusion With effective protection measures for internal and external irradiation in place, the annual exposure doses for seed production personnel and operator’s hand are below the national limits. Adequate measures should be taken on hand protection.
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Objective To investigate radioactive nuclide 210Po content in the diet of residents and internal irradiation dose caused by them. Methods The major food distribution market is selected, more than 50 kinds of food samples such as meat, vegetables, fruits, aquatic products, cereals, milk are collected, the combined method ofwet ashingand metal deposition is used to measure 210Po content of food samples, and analysis of monitoring data and estimationof irradiationexposure dose of residents caused by 210Po and their relative contribution are made. Results In the food samples, the specific activity of 210Po was 8.34 mBq/kg· fresh～16.9 Bq/kg· fresh, and the content of 210Po in hairtail was higher, its value was16.9 Bq/kg· fresh, which was higher than other freshwater fish. According to the data, the annual intake of residents was 108 Bq/person, and the annual effective dose of adult caused by 210Po was 129 μSv/a.The relatively large contribution were from flour (15.2%), eggs (22.0%), aquatic products (17.1%) and vegetable oil (18.1%). Conclusion The annual intake of 210Po for residents is lower than the current limit for adults of which the value is 2 200 Bq.
RESUMO
Objective To observe the effects of recombinant human thyroid stimulating hormone(rhTSH)mediated 131I therapy for differentiated thyroid carcinoma(DTC).Methods 96 patients of DTC from January 2011 to May 2013 in the Central Hospital of Nanyang which randomly divided into study group and control group,48 cases in each group.Two groups of patients underwent total thyroidectomy or subtotal operation.The study group received rhTSH mediated 131 I radioiodine therapy,the control group received the therapy of thyroid hormone withdrawal mediated 131 I radioiodine therapy. Results The levels of the serum thyroid stimulating hormone(TSH)and thyroid immune globulin(Tg)of the control group were significantly difference that compared before treatment with radioiodine therapy to clear thyroid(P<0.05).The levels of the serum free thyroxine T3(FT3),free thyroxine T4(FT4)were significantly lower than that before stoping thyroid hormone(P<0.05).The levels of the serum TSH and Tg of the study group were significantly higher after injected rhTSH than before(P<0.05);but the levels of the serum FT3,FT4 were no significant difference.The levels of the serum TSH 、FT3、FT4、Tg of the study group were significantly higher than that of control group after treated (P<0.05 ).The effectively rate of control group with radioiodine therapy was 66.7%from 131 I whole body imaging showed after 3~6 months,while study group was 70.8%,two groups of radioiodine therapy effective rate were significant difference(P<0.05 ).The security of study group was higher than that of control group(P<0.05 ). Conclusion The application of rhTSH can similar effectively improve the level of serum TSH in patients as method of stoping with thyroid hormone,but the adverse reactions in patients are fewer and the treatment time is shorter.