Spatial Distribution and Radiological Risk Quantification of Natural Radioisotopes in the St. Martin’s Island, Bangladesh

Elevated levels of environmental radioactivity in fluvial sediment: origin and health risk assessment

“…The radiological risks are evaluated using the activity utilization index (AUI), the gamma representative level index ( I γ ) and the excess lifetime cancer risk (ELCR), detailed in Table 4. 15,19,22,56–60…”

“…The radiological risks are evaluated using the activity utilization index (AUI), the gamma representative level index (I g ) and the excess lifetime cancer risk (ELCR), detailed in Table 4. 15,19,22,[56][57][58][59][60] Again, several research studies [61][62][63] have outlined the complete approach of the PMF (positive matrix factorization) model for explaining the origin of measured geo-environmental parameters as well as their quantitative contributions. Equations affiliated with the PMF model are as follows:…”

Indexical and statistical approaches to investigate the integrated origins of elements in the sediment of Teesta River, Bangladesh: sediment quality and ecological risk assessment

“…14,77,81 Aside from this, a very high correlation between typical lithophile elements Th and U (r = 0.886; p < 0.01) (Table S5 †) in this study demonstrated similar sedimentary characteristics and was hypothesized to be governed by wave hindering heavy minerals, namely monazite [(La, Ce, Nd, Th) PO 4 ] (Th-rich mineral) and zircon (ZrSiO 4 ) (U-rich mineral). 1,82 As a result, in an oxidizing environment, Th is weather-resistant (remains as insoluble Th 4+ ), but U transforms into a soluble oxyanion-complex (UO 2 ) and may easily be depleted from sediment by leaching and/or weathering. 1,14,68 Thus, U mobilization enhanced the Th/U ratio in Teesta River basin sediments, indicating monazite predominance.…”