U(VI) Adsorption onto Low Dose Radiation Acclimated Tradescantia Fluminensis

The plants that long-term grown in radiation area could be acclimated by low dose radiation (LDR). In this paper, LDR acclimated Tradescantia fluminensis (Commelinaceae) was first collected as a biomass adsorbent towards uranium adsorption. Comparative experiments verified the potential radiation effects of LDR acclimation, moreover, qe values of the wild and LDR acclimated Tradescantia fluminensis were ~16 mg/g and 20 mg/g, respectively. U(VI) adsorption amount gradually reached equilibrium after 180 min shaking, and the adsorption process described well by the pseudo-second-order model. However, ionic strength has no obvious effect on the qe values. SEM and TG-DSC suggested good structural stability of LDR acclimated Tradescantia fluminensis during the U(VI) adsorption process. FTIR and XPS verfied the surface coordination of U(VI) via -OH and -COOH groups on LDR acclimated Tradescantia fluminensis surface, and the increasing amounts of the two groups could account for the improved U(VI) adsorption capacity compared to the wild Tradescantia fluminensis. Our present work can indicate that LDR acclimation could be a novel way to obtain biomass adsorbents for U(VI) removal from aqueous solutions.

Comprehensive exposure assessments from the viewpoint of health in a unique high natural background radiation area, Mamuju, Indonesia

Mamuju is one of the regions in Indonesia which retains natural conditions but has relatively high exposure to natural radiation. The goals of the present study were to characterize exposure of the entire Mamuju region as a high natural background radiation area (HNBRA) and to assess the existing exposure as a means for radiation protection of the public and the environment. A cross-sectional study method was used with cluster sampling areas by measuring all parameters that contribute to external and internal radiation exposures. It was determined that Mamuju was a unique HNBRA with the annual effective dose between 17 and 115 mSv, with an average of 32 mSv. The lifetime cumulative dose calculation suggested that Mamuju residents could receive as much as 2.2 Sv on average which is much higher than the average dose of atomic bomb survivors for which risks of cancer and non-cancer diseases are demonstrated. The study results are new scientific data allowing better understanding of health effects related to chronic low-dose-rate radiation exposure and they can be used as the main input in a future epidemiology study.