The increasing likelihood of AgNP releases highlights the importance to understand their interactions with plants and assess phytotoxicity and trophic transfer potential. One-month-old poplars (Populus deltoids � nigra) were exposed to a wide range of concentrations (0.01 to 100 mg/L) of 25-nm AgNPs. These AgNPs exerted toxicity after 10-day exposure in quarter-strength Hoagland solution (e.g., poplars died when exposed to 100 mg/L). However, sublethal exposure (e.g., at 1.0 mg/L) significantly (p < 0.05) increased poplar evapotranspiration and biomass growth. Ag+ (added as AgNO3) was more toxic than AgNPs and killed poplars at 1.0 mg/L, although it similarly enhanced growth at sub-lethal concentrations (0.1 mg/L). Changes in total Ag concentrations remaining in the hydroponic medium indicated significantly faster removal of Ag+ than AgNPs. Overall, the observed stimulation precludes generalizations about the phytotoxicity of engineered nanoparticles and underscores the importance to discern the underlying (potentially hormetic) mechanisms to enhance primary productivity.

Stimulatory effect on poplar by low (sub-lethal) concentrations of silver nanoparticles (AgNPs)

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.