The diet is an important yet poorly characterized exposure pathway for a range of chemicals released the production and consumption of energy and other industrial processes. Comparative risk analyses and life cycle impact assessments must account for dietary intake, but the different ways vegetation influences fate and exposure complicate modeling the source-to-dose relationship. This presentation describes a terrestrial vegetation module that we developed and incorporated into a regional fate and exposure model. We use the model to evaluate the dual role of terrestrial vegetation as both an environmental media and as an exposure media. We find that the main limitation to modeling dietary exposure continues to be uncertainty about the uptake of environmental chemicals into agricultural commodities.  We conclude the presentation with a brief discussion of new research aimed specifically at reducing uncertainty about the transfer of environmental pollutants into the agricultural food chain.