Cerium oxide nanoparticle (nCeO2) interactions with the short chain perfluoroalkyl substance PFBS on radish plants

N. Zuverza-Mena, J. C. White
Connecticut Agricultural Experiment Station,
United States

Keywords: Ceria nanoparticles, Perfluorobutane sulfonic acid, Phytotoxicity, Radish, Emerging contaminants

Summary:

The emerging contaminants polyfluoroalkyl and perfluoroalkyl substances (PFASs) are associated with significant health risks and environmental concerns. Perfluorobutanesulfonic acid (PFBS) is one of the more than 3000 PFASs for which we have limited understanding. PFBS has already been detected in the environment, although there are no official PFASs regulations. In soil, PFBS may encounter other contaminants whose use is also increasing such as ceria nanoparticles (nCeO2), bringing unknown effects to terrestrial and agricultural systems. In this study, we grew radish plants (Raphanus sativus) in potting mix with PFBS at 1000 mg/kg alone or in the presence of ceria nanoparticles (nCeO2; 125 mg/kg). While PFBS decreased the germination from 97 % (control) to 63 %, the inclusion of nCeO2 partially alleviated some of the PFBS toxicity by increasing the germination to 73 %. This co-exposure benefit was lost at later stages of the plant life cycle. The aerial biomass remained statistically equivalent to the control. However, the vegetable number yield and biomass was reduced by more than 50% upon PFBS exposure, regardless of the presence of nCeO2. Moreover, PFBS caused a significant nutrient imbalance in the radish tubers, while overall, the exposure to nCeO2 alone did not alter the elemental composition. Interestingly, this imbalance was mostly observed in the edible portion of the plant, and not as strongly in the shoots or roots. Further analysis should be carried on under more realistic concentrations. We hypothesize that if the analytes are present in comparable amounts, nCeO2 may alleviate some of the phytotoxic effects of PFBS exposure.