Accumulation in plants, microorganisms, and animals

Readily soluble pertechnetate ions in soil may compete with nutrient ions for uptake by plant roots possibly leading to accumulation in foodstuffs. 

Ibxicity symptoms in wheal were also observed at the 0.1 pg/g level. The plants were stunted and there was a necrosis of the blade tips and margins. Growth did not occur at the 1.0 pg/g level. Wheal exhibited the highest Tc concentrations in the blade [46J. The plant affinity for TcO applied to soil is high and generally exceeds that reported for other non-nutrient nuclides arising from the nuclear fuel cycle [48]. 

The accumulation of Tc by tumbleweed and chealgrass on arid. soils was measured. Tire initial soil concentration of 10 g Tc/g added to the soil as pertechnetale was traced by Tc. At the three month harvest time the uptake of the added Tc ranged from 23 to 82 % for tumbleweed and 10 to 69 % for cheatgrass [49]. 

The sorption of TcOj by roots of hydroponically grown soybean seedlings (Glycine max.) was shown to be linear from 10 M pertechnetate solutions for at least 6 h and to exhibit characteristics of carrier-mediated transport commonly associated with the sorption of nutrient ions in higher plants. Analyses of TcO uptake in the presence of individual nutrient anions revealed the sorption to be competitively inhibited by sulphate, phosphate, selenate. and molybdate indicating the use of common transport mechanisms [54], 

To assess the relative extent of - Tc sorption and its mobility, plants were grown for 40 days in hydroponics amended with 10 M Tc04. Uptake rates in roots and leaf concentrations after 48 h were determined (Tabic 4.3. A). 

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