This study was developed with the aim of determining the activity concentration of ²²⁶Ra, ²²⁸Ra, ²¹⁰Pb and ⁴⁰K in samples of technosols (soils formed by the deposition of tailings from the dam rupture on the banks of rivers and in riverside regions) and in natural soils from the Mariana region in Minas Gerais, after the Mariana tragedy, which is considered the biggest accident in terms of volume of material dumped. The soil samples were analyzed by gamma spectrometry in a hyperpure germanium detector system. The concentrations of all studied radionuclides were higher in the natural soils of Mariana (²²⁶Ra 471–1204 Bq kg⁻¹, for ²²⁸Ra 415–789 Bq kg⁻¹, for ²¹⁰Pb 327–641 Bq kg⁻¹ and for ⁴⁰K 707–2080 Bq kg⁻¹) than in the technosols formed after the accident (²²⁶Ra of 179–384 Bq kg⁻¹, for ²²⁸Ra of 60–269 Bq kg⁻¹, for ²¹⁰Pb of 463–818 Bq kg⁻¹ and for ⁴⁰K of 105–204 Bq kg⁻¹), indicating that the region may present some type of radioactive anomaly or that the use of fertilizers in agricultural soils may have promoted some increase in these elements. On the other hand, the concentrations in the technosols were high when compared with tailings from iron mining in other countries (42 Bq kg⁻¹ for ²²⁶Ra and 16 Bq kg⁻¹ for ²¹⁰Pb), as well as tailings from phosphorus mining in Brazil and in the world. It is admitted that these high values are the result of the mixture of pure tailings with the natural soil of the region, that presented radioactive anomaly, and also result of the peculiar geology of Mina Alegria.

开展这项研究的目的是确定技术溶胶样品中²²⁶ Ra、²²⁸ Ra、²¹⁰ Pb 和⁴⁰ K的活性浓度（由河岸和河滨地区大坝破裂产生的尾矿沉积形成的土壤）在马里亚纳悲剧发生后，米纳斯吉拉斯州马里亚纳地区的天然土壤中，这被认为是倾倒材料量最大的事故。在超纯锗探测器系统中通过伽马光谱法分析土壤样品。所有研究的放射性核素在马里亚纳自然土壤中的浓度都较高（²²⁶ Ra 471–1204 Bq kg ^-1，对于²²⁸ Ra 415–789 Bq kg^-1，对于²¹⁰ Pb 327-641 Bq kg ^-1和对于⁴⁰ K 707-2080 Bq kg ^-1）比事故后形成的技术溶胶（²²⁶ Ra 为 179-384 Bq kg ^-1，对于²²⁸ Ra 为 60 -269贝千克^-1，对于²¹⁰的463-818贝公斤铅^-1和⁴⁰的K 105-204贝千克^-1)，表明该地区可能存在某种类型的放射性异常，或者在农业土壤中使用化肥可能促进了这些元素的一些增加。另一方面，与其他国家铁矿开采的尾矿（²²⁶ Ra为42 Bq kg ^-1和²¹⁰ Pb为16 Bq kg ^-1）相比，技术溶胶中的浓度较高，以及磷矿开采的尾矿。巴西和世界。人们承认，这些高值是纯尾矿与该地区天然土壤混合的结果，呈现出放射性异常，也是米纳阿莱格利亚奇特地质的结果。