Rice seedlings were grown for 30 days in nutrient solution containing yttrium oxide or zirconium oxide nanoparticles. Neither treatment changed visible growth, but yttrium oxide raised root lipid peroxidation and suppressed some antioxidant enzymes. Yttrium accumulated heavily in roots with limited movement to shoots.
Key numbers
- Exposure levels: 5, 25 and 100 mg/L nanoparticles in Hoagland solution for 30 days (Methods, Section 2.1).
- Root yttrium 5014.12 to 11,255.05 mg/kg dry weight under yttrium oxide treatments, about 50.6 to 113.5 times the control (Abstract; Section 3.5).
- Shoot yttrium showed only limited change; numeric shoot values are shown only as a standardized heatmap (Figure 6).
Methods (brief)
Seedlings grew in a completely randomized hydroponic design with seven treatments and four bottles of three seedlings each. Shoots and roots were dried, digested with nitric acid and hydrogen peroxide, and analyzed by ICP-MS at a commercial laboratory. Malondialdehyde, peroxidase and catalase were measured, and roots were examined by transmission electron microscopy.
Evidence fitness
Supports statements that yttrium from oxide nanoparticles is retained mainly in rice roots in short hydroponic exposures. It does not measure grain and does not support statements about yttrium in rice as food or about human exposure.
Limitations
Seedling stage only, no grain. Nanoparticle concentrations were set high by the experimenters (up to 100 mg/L). Root values may include particles adhering to root surfaces. Shoot concentrations are not reported numerically, and analytical quality control is not described.
Related evidence
Update history
No substantive edit history is available in this build. The full commit record is available in git.