Analysis of the Potential for Plant Uptake of Trichloroethylene and an Assessmentof the Relative Risk from Different Crop Types

摘要

This research expands our limited knowledge on the influence of plants on thefate and effects of trichloroethylene (TCE), providing a screening tool on which to base decisions regarding the need for actual sampling of plants. First, physicochemical properties of TCE--vapor pressure, Henry's Law constant, water solubility, octanol-water partition coefficient, molecular weight, and half-life--were screened against relationships reported in literature to evaluate TCE plant uptake potential. This screening approach indicated TCE may be transferred to plants via retention by root surfaces, root uptake and translocation, and foliar uptake. Next, the PLANTX model developed by Trapp and others was applied to a representation of a soybean plant to determine minimum soil TCE concentrations which result in plant TCE levels exceeding 5 micrograms per liter of solution (ug/L). The simulations indicated that stem and root crops are most susceptible to TCE uptake and accumulation, while significantly higher soil and air TCE concentrations are required to produce leaf and fruit TCE levels of concern to human health. The above procedures were then applied to an off-site contamination situation near Hill Air Force Base, Utah. The simulations indicate that existing TCE concentrations in irrigation water from contaminated residential wells and springs do not result in plant TCE levels greater than 5 ug/L. Trichloroethylene, Plant uptake, Bioavailability, Translocation.