Abstract

Purpose

The effects of radioactivity on human health have been debated for many years but there are still important gaps that need to be addressed especially related to the effects of high natural background radiation on the local population. The beach of Meaípe, in the city of Guarapari (Brazil), emits natural gamma radiation due to the presence of monazite sands. We aimed to investigate the effects of gamma radiation doses on the biological system of wistar rats using a physical simulator of gamma radiation designed using Meaípe monazite sands.

Methods

Female Wistar rats were divided into three groups, submitted to no radiation (control group) and to continuous radiation levels, one of very high level (20 μSv h⁻¹) and another of high level (3.6 μSv h⁻¹). The three group of animals were monitored weekly for 3 months and at the end of the study the animals were sacrificed, and the organs were extracted and weighed for anthropometric, oxidative stress and histological evaluations.

Results

Exposure to radiation released by the monazite sands did not cause anthropometric alterations or blood pressure change in the animals. Similarly, there was no change in the quantification of ovarian follicles between the radiation groups and the control group. There was no difference in the oxidative stress quantification by the thiobarbituric acid reactive substance and advanced oxidation protein product methods in the ovaries. There were no evidenced damages in the structure of the renal tissue. It was observed the presence of granulomas in the hepatic tissue and alterations in the nuclei of the hepatocytes.

Conclusions

Our results suggest that the continuous exposure of females rats to 3.6 and 20 μSv h⁻¹ doses of gamma radiation slightly affected the hepatic tissue, but did not alter the histological parameters in the kidneys and ovaries and oxidative stress.

中文翻译：

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使用物理模拟器通过连续和自然伽马射线评估大鼠诱发的生物效应。

摘要

目的

放射性对人类健康的影响已经争论了很多年，但是仍然存在重要的差距需要解决，尤其是与高自然本底辐射对当地居民的影响有关。位于瓜拉帕里（巴西）市的Meaípe海滩由于存在独居石沙而散发天然的伽马射线。我们旨在研究使用Meaípe独居石砂设计的伽玛辐射物理模拟器对伽玛辐射剂量对wistar大鼠生物系统的影响。

方法

将雌性Wistar大鼠分成三组，分别接受无辐射（对照组）和连续辐射水平，一组为极高水平（20μSvh ^-1），另一组为高水平（3.6μSvh ^-1）。每周监测这三组动物，持续3个月，研究结束时，处死动物，提取器官并称重，以进行人体测量，氧化应激和组织学评估。

结果

暴露于独居石沙子释放的辐射不会引起动物的人体测量学改变或血压变化。同样，辐射组和对照组之间的卵泡定量没有变化。在卵巢中，通过硫代巴比妥酸反应性物质进行的氧化应激定量分析和先进的氧化蛋白生成方法没有差异。没有证据表明肾脏组织结构受损。观察到肝组织中肉芽肿的存在和肝细胞核的改变。

结论

我们的结果表明，雌性大鼠连续暴露于3.6和20μSvh ^-1剂量的γ射线会轻微影响肝组织，但不会改变肾脏和卵巢的组织学参数以及氧化应激。