Bioaccumulation, uptake, and toxicity of carbamazepine in soil-plant systems

Since the detection of active pharmaceutical ingredients (APIs) in various environmental media, research has explored the potential uptake and toxicity of these chemicals to species inhabiting these matrices. Specifically, pharmaceuticals, including the antiepileptic API carbamazepine (CBZ), are taken up from soil by a range of plants. Many short-term studies have also suggested that certain APIs induce toxicity in plants. However, the effects of APIs on fruiting plants remain relatively unexplored. The present study investigated the uptake, bioaccumulation, and toxicity of CBZ in Cucurbita pepo (zucchini) from seed to full maturity across a range of CBZ exposure concentrations in soil (0.1-20 mg/kg). Results of biomass, chlorophyll, starch and total nitrogen (N) concentration in C. pepo indicated toxicity at soil concentrations of ≥10 mg/kg. There were clear visual indications of increasing toxicity on leaves, including chlorosis and necrosis, from soil concentrations of 1 up to 20 mg/kg. The present study also revealed novel insights into the effect of CBZ accumulation on C. pepo fruiting: female C. pepo flowers were unable to set fruit when leaf concentrations were ≥14 mg/kg. These findings may have implications for future agricultural productivity in areas where reclaimed wastewater containing APIs is a source of irrigation. Detectable CBZ concentrations were found in edible C. pepo fruit, indicating the possibility of trophic transfer. Environ Toxicol Chem 2018;37:1122-1130. © 2017 SETAC.