Trees as Monitors of Tritium in Soil Water

Abstract

Abstract Tritium ( 3 H) activities in the foliage of forest trees were found to reflect 3 H activities in soil water along the perimeter of a retired low‐level radioactive waste disposal site. Spatial variability in foliage 3 H activity clearly delineated patterns of 3 H in soil water as deep as 3 m. Late summer increases in foliage 3 H activity paralleled increases in soil water activity and also suggested greater uptake of water from deep reservoirs after surface soils had dried out. White and chestnut oak ( Quercus alba L. and Q. prinus L.) dominated the study area and were good monitors of 3 H, regardless of tree size. Spatial patterns of 3 H in foliage of these species over a 5‐ha watershed were interpretable in terms of the local landscape and the probable pathways of movement of contaminated water originating on the disposal site. Results of this study suggest that trees and other deeply rooted plants may serve as simple and effective monitors of soil water contamination and may therefore be useful additions to permanent monitoring systems.