Uptake of uranium by spinach grown in andosols accumulating trace amounts of fertilizer-derived uranium

Yamaguchi, Noriko*; Watanabe, Yoko ; Kawasaki, Akira*; Inoue, Chiaki*

Long-term agricultural practices result in the accumulation of uranium (U) in plowed soils, as phosphate fertilizers contain about 90740 mg/kg of uranium as impurity. It is difficult to evaluate whether or not fertilizer-derived U affect public dose of U through agricultural products because U is ubiquitous elements in the soil environment. However, chenopodiaceous plants such as spinach are known to uptake higher amounts of U than the other vegetables and crops. In order to assess the potential risks caused by trace U present in agricultural fields, we investigated U uptake by spinach grown in soil of elevated concentration of U possibly due to phosphorus fertilization.