Assessment of radiation exposure and public health before and after the operation of Sanmen nuclear power plant.

Introduction: Sanmen nuclear power plant (SNPP) operates the first advanced passive (AP1000) nuclear power unit in China. Methods: To assess the radiological impacts of SNPP operation on the surrounding environment and the public health, annual effective dose (AED) and excess risk (ER) were estimated based on continuous radioactivity monitoring in drinking water and ambient dose before and after its operation during 2014-2021. In addition, the residents' cancer incidence was further analyzed through authorized health data collection. Results: The results showed that the gross α and gross ß radioactivity in all types of drinking water were ranged from 0.008 to 0.017 Bq/L and 0.032 to 0.112 Bq/L, respectively. The cumulative ambient dose in Sanmen county ranged from 0.254 to 0.460 mSv/y, with an average of 0.354 ± 0.075 mSv/y. There is no statistical difference in drinking water radioactivity and ambient dose before and after the operation of SNPP according to Mann-Whitney U test. The Mann-Kendall test also indicates there is neither increasing nor decreasing trend during the period from 2014 to 2021. The age-dependent annual effective doses due to the ingestion of drinking water or exposure to the outdoor ambient environment are lower than the recommended threshold of 0.1 mSv/y. The incidence of cancer (include leukemia and thyroid cancer) in the population around SNPP is slightly higher than that in other areas, while it is still in a stable state characterized by annual percentage changes. Discussion: The current comprehensive results show that the operation of SNPP has so far no evident radiological impact on the surrounding environment and public health, but continued monitoring is still needed in the future.

Long-term investigation of environmental radioactivity levels and public health around the Qinshan Nuclear Power Plant, China.

To evaluate the impact of the Qinshan Nuclear Power Plant (Qinshan NPP) in normal operation on the surrounding environment and population, the radioactivity levels of drinking water and the ambient environment, as well as the residents' cancer incidence, were continuously monitored for a period of 9 years (2012-2020). All of the gross α and ß radioactivity concentrations in drinking water were less than the WHO recommended values (0.5 Bq/L for gross α and 1 Bq/L for gross ß). The results of ambient environment accumulated dose monitored by thermoluminescent dosimeters (TLDs) indicated that the ambient environment radioactive level around the Qinshan NPP is consistently at natural background radiation levels. The age-dependent annual effective doses due to the ingestion of tap water or exposure to the outdoor ambient environment are lower than the reference dose of 0.1 mSv/year. The corresponding excess risks are at relatively low levels. Thus, the consumption of drinking water and outdoor activities are not expected to give rise to any detectable adverse effects on the health of the public around the Qinshan NPP. For all cancers combined, the age-standardized incidence rate by the Chinese 2000 standard population of the inhabitants living around Qinshan NPP is consistent with that of Zhejiang Province as a whole. Based on current radiation risk estimates, radiation exposure is not a plausible explanation for any excess cancers observed in the vicinity of the Qinshan NPP.

Case Report: Occupation Radiation Disease, Skin Injury, and Leukemia After Accidental Radiation Exposure.

Objective: Follow-up observation of radiation accident in which a worker developed acute radiation disease and eventually died of leukemia. The case provided key practical information for the study on clinical effects of radiation on the health of workers. Case Presentation: We observed and followed-up the progression and effect of radiation exposure at various stages in a 28-year-old male patient. We examined the chromosomal morphology, white blood cell count, and sperm count. Laboratory tests for leukemia diagnosis and other clinical parameters were performed. Results: After the patient was irradiated, the white blood cell level decreased, the sperm count dropped to 0, and the libido completely disappeared. The patient's chromosome aberration cell rate and total chromosome aberration cell rate were 7.33 and 7.66%, respectively. Examination of leukemia diagnostic experiments revealed that abnormal cells accounted for 60%; bone marrow examination showed that prolymphocytes abnormally proliferated, accounting for 89%, and had positive extracellular iron staining. After the initial treatment, the patient's white blood cell level increased and was finally maintained at a normal level, the sperm count returned to normal levels, and libido was restored. The patient died of acute lymphoblastic leukemia 34 years after the exposure. Conclusion: More attention has been paid to the long-term effects of ionizing radiation-induced malignant tumors. The occupational protection of radiographic inspection workers should be strengthened to reduce and avoid occupational injuries to protect the health and safety of workers.

Protective effect of hydrogen-rich saline against radiation-induced immune dysfunction.

Recent studies showed that hydrogen can be used as an effective radioprotective agent through scavenging free radicals. This study was undertaken to evaluate the radioprotective effects of hydrogen on immune system in mice. H(2) was dissolved in physiological saline using an apparatus produced by our department. Spleen index and histological analysis were used to evaluate the splenic structural damage. Spleen superoxide dismutase, GSH, MDA were measured to appraise the antioxidant capacity and a DCF assay for the measurement of radical oxygen species. Cell apoptosis was evaluated by an Annexin V-FITC and propidium iodide staining method as well as the apoptotic proteins such as Bcl-2, Bax, caspase-3 and c-caspase-3. CD4+ and CD8+ T cells subtypes were detected by flow cytometry with FITC-labelled antimouse CD4 and PE antimouse CD8 staining. Real-time PCR was utilized to determine the CD4+ T cell subtypes and related cytokines. Our study demonstrated that pre-treatment with H(2) could increase the spleen index and attenuate the radiation damage on splenic structure. Radical oxygen species level was also reduced by H(2) treatment. H(2) also inhibited radiation-induced apoptosis in splenocytes and down-regulated pro-apoptotic proteins in living mice. Radiation-induced imbalance of T cells was attenuated by H(2). Finally, we found that H(2) could regulate the polarization of CD4+ T cells and the level of related cytokines. This study suggests H(2) as an effective radioprotective agent on immune system by scavenging reactive oxygen species.