Plant Uptake of Trace Organic Contaminants in Effluent-Dominated Streams: An Overlooked Terrestrial Exposure Pathway
Angela N. Stiegler, Aidan R. Cecchetti, David L. Sedlak
Abstract
Uptake and translocation of water-soluble organic compounds by plants represent important means through which terrestrial organisms can be exposed to organic contaminants. In terrestrial systems adjacent to wastewater effluent-dominated streams (e.g., riparian corridors), insects, mammals, and birds could be exposed to trace organic contaminants through this pathway, especially in arid regions where other water sources are scarce. Analysis of the antiepileptic drug, carbamazepine, in plants grown under conditions that mimic effluent-dominated riparian zones indicates that concentrations in plant tissues exceed levels that may pose risks to herbivorous and/or detritivorous organisms. Plant uptake of carbamazepine exhibited considerable interspecies variability and distinct spatial and temporal trends. It also showed evidence of in-planta transformation. Because effluent-dominated riparian zones serve as important habitats for terrestrial species in arid regions, plant uptake and translocation of wastewater-derived trace organic contaminants should be considered when assessing the potential ecotoxicological impacts of municipal wastewater effluent discharges.