Alumina production from bauxite ore gives rise to a large amount of liquid and solid waste since the production of 1 kg of alumina involves the same weight of solid residue, the well-known red muds enriched in iron and heavy metals. Up to now, without any valorization of by-products, the red muds have been stored in artificial ponds which are a potential source of pollutants for the surroundings due to the uplift of red dust under strong wind conditions. The goal of the current work is to perform an in situ study of the transfer of red mud micro particles in the atmosphere and in the terrestrial environment around the red mud disposition basins. To this end, the activity concentration of NORM (Naturally Occurring Radioactive Materials such as ²³⁸U, decay products and ²³²Th) determined in plant leaves (Quercus robur and leaf vegetables) and in grains (wheat) is compared with the activity of the atmospheric micro particles, both taken in the environment of the red mud disposition basins (100–1,500 m). The activity ratios of NORM in vegetation and atmospheric micro particles are also compared to the ratios of potential sources of dust, such as soil and, above all, the red mud and bauxite emitted from the basins and from the piles, respectively.

The increase in ²³²Th and ²³⁸U activity concentration in a few tree leaves (by a factor of 9 and 4, respectively) and in some aerosol samples is accompanied by a decrease in ²³⁸U/²³²Th activity ratio for these matrices. Low ²³⁸U/²³²Th is also observed in bauxite and red mud. This suggests that the airborne particles emitted by bauxite piles and red mud basins first contaminate the atmosphere and then the leafs surfaces, after deposition. Locally-produced foodstuffs at a distance greater than 1,000 m from the ponds do not show any excess radionuclides, suggesting the low influence of airborne particles from the alumina production. Further variations in the ²¹⁰Po/²¹⁰Pb ratio in the plants and the atmospheric micro particles are consistent with the variation over time of these radionuclides coming in all likelihood from the atmosphere rather than from the aluminum industry.

从铝土矿生产氧化铝会产生大量液体和固体废物，因为生产 1 公斤氧化铝涉及相同重量的固体残渣，即众所周知的富含铁和重金属的赤泥。到目前为止，赤泥一直被储存在人工池塘中，没有任何副产品的价值，由于强风条件下红色粉尘的上升，这对周围环境是潜在的污染物来源。当前工作的目标是对赤泥微粒在大气中和赤泥沉积盆地周围的陆地环境中的转移进行原位研究。为此，NORM（Naturally Occurring Radioactive Materials，如²³⁸ U、衰变产物和²³²在植物叶子（栎类和叶菜类）和谷物（小麦）中测定的 Th)与大气微颗粒的活性进行比较，两者均在赤泥沉积盆地 (100-1,500 m) 的环境中获取。植被和大气微粒中 NORM 的活动率也与潜在的灰尘源的比率进行了比较，例如土壤，最重要的是分别从盆地和堆放出的赤泥和铝土矿。

一些树叶（分别为 9 和 4 倍）和一些气溶胶样品中²³² Th 和²³⁸ U 活性浓度的增加伴随着这些基质的²³⁸ U/ ²³² Th 活性比的降低。在铝土矿和赤泥中也观察到低²³⁸ U/ ²³² Th。这表明铝土矿堆和赤泥盆地排放的空气中的颗粒首先污染大气，然后在沉积后污染叶子表面。距池塘 1,000 米以上的当地生产的食品没有显示出任何过量的放射性核素，这表明氧化铝生产中空气中颗粒的影响很小。^{210 的}进一步变化植物和大气微粒中的Po/ ²¹⁰ Pb 比率与这些放射性核素随时间的变化一致，这些放射性核素很可能来自大气而不是铝工业。