Soil-to-plant halogens transfer studies 1.Root uptake of radioiodine by plants

V.Kashparov (a),C.Colle (b,) ,S.Zvarich (a),V.Yoschenk (a), S.Levchuk(a) ,S.Lundin (a)
Journal of Environmental Radioactivity 79; 187-204

Long-term controlled experiments under natural conditions in the .eld have been carried out in the Chernobyl Exclusion zone in order to determine the parameters governing radioiodine transfer to plants from four types of soils (podzoluvisol,greyzem and typical and meadow chernozem)homogeneously contaminated in the 20-cm upper layer with an addition of 125 I.An absence of 125 I depletion in arable soil layers due to volatilization was noted up to one year after contamination.During one year,depletion due to the vertical migration of radioiodine from the arable layer of each of the soils did not exceed 4%of the total 125 I content.Radioiodine concentration ratios (CR)were obtained in radish roots,lettuce leaves, bean pods,and wheat grain and straw.The highest CR values were observed in podzoluvisol: 0.01 .0.03 for radish roots and lettuce leaves,0.003 .0.004 for bean pods and 0.001 for wheat grains.In the other three soils,these values were one order of magnitude lower.The parameters relating to changes in radioiodine bioavailability were determined,based on the contamination dynamics of plants in field conditions.

(a) Ukrainian Institute of Agricultural Radiology (UIAR),Mashinostroiteley Str.7, Chabany,Kiev Region 08162,Ukraine

(b) Institute for Radioprotection and Nuclear Safety (IRSN/DEI/SECRE),Cadarache bat 159, BP 3,13115 Saint Paul-Lez-Durance,France