Incorporation of chromium in vegetation through root uptake and foliar absorption pathways

Abstract

The deposition of chromate transported in cooling tower drift has been identified as a potential environmental problem. Research at the Oak Ridge Gaseous Diffusion Plant (ORGDP) cooling towers has provided quantitative evidence of the transfer of chromium from drift to vegetation and soil, its short-term effects on the vegetation, and its possible accumulation in the soil. In this paper, the potential for incorporation of chromium in vegetation by root uptake and foliar absorption was studied using water from the chromated recirculating water system of the ORGDP cooling towers. Concentration factors for roots (5.1–14.3) of plants grown in soil treated with chromated recirculating water were two orders of magnitude greater than concentration factors for leaves (0.05–0.20), indicating that the chromium was immobilized at the site applied (roots) and not transported to aboveground parts. Similarly, concentration factors in roots of the plants treated with foliar application of chromated recirculating water ranged from 0.01 to 0.10, indicating that the chromium was not transported basipetally.