The factors affecting the uptake of I-131 in Chinese white cabbage (Brassic
a Chinensis Linn) were studied. The time required for the ratio between the
activity in the vegetable (Bq kg(-1) dry mass) and the activity in the soi
l (Bq kg(-1) dry mass) to reach equilibrium was around 72 h derived from an
investigation period of 145 h. The ratio was also dependent on the mass of
the vegetable (increased by more than twice when the vegetable mass was de
creased to around 60%), the growth period of the vegetable (almost linearly
decreased from 3.0 x 10(-2) to 1.1 x 10(-2) when the growth period changed
from 66 to 81 d) and the season of culture, while it was independent of th
e concentration of I-131 applied to the soil. The mean concentration ratio
obtained for 51 samples was (6.3 +/- 4.4) x 10(-2). (C) 2000 Elsevier Scien
ce Ltd. All rights reserved.