HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Simon, S. L. Articles by Deming, E. J. Search for Related Content PubMed Articles by Simon, S. L. Articles by Deming, E. J. Agricola Articles by Simon, S. L. Articles by Deming, E. J.

Time-dependent Leaching of Radium from Leaves and Soil¹

ABSTRACT

The accumulation of Ra or other radionuclides in vegetation via root uptake depends on the availability and uptake rate from soil, in addition to the rate of loss from the leaves due to natural leaching processes. We conducted studies to determine the time-dependent leachable fraction of ²²⁶Ra from soil as a function of time after soil spiking and the loss rate of internal ²²⁶Ra from leaves due to leaching by exposure to natural field conditions. The leachable fraction of Ra from spiked soil decreased exponentially over time to a value of 0.1% after approximately 28 d. The internal Ra activity in leaves decreased exponentially to 40% of the original activity after 1 yr of exposure to outdoor conditions in a semiarid environment. The relationship of these two phenomena to the accumulation of Ra in plants via root uptake is illustrated by the equilibrium solution of a first-order differential equation.

Key Words: root uptake • ²²⁶Ra • radiotracers • internal plant contamination • modeling

¹ This work was supported by U.S. Dep. of Energy Contract DE-AC02-79EV10305 with Colorado State Univ.

² Both authors previously at Dep. of Radiology and Radiation Biology, Colorado State Univ., Ft. Collins, CO 80523. Current address for S.L. Simon is Div. of Epidemiology, Univ. of Utah, Salt Lake City, UT 84108; E.J. Deming is now at Oak Ridge Associated Univ., Oak Ridge, TN 37831.

Received for publication July 23, 1985.