A recently published study suggests that soybeans grown in soil containing nanoparticles of zinc oxide or cerium oxide were affected by the presence of the nanomaterials. John Preister, et al., “Soybean susceptibility to manufactured nanomaterials with evidence for food quality and soil fertility interruption,” Proceedings of the National Academy of Sciences, August 20, 2012 (online). Researchers grew soybeans to maturity in soil to which they added either zero, 0.05, 0.,1 or 0.5 grams of zinc oxide or cerium oxide per kilogram of soil.
The leaves of soybean plants exposed to zinc oxide contained more zinc than leaves of plants grown in unexposed soil, and the zinc levels in the plants increased along with increases in manufactured nano-zinc oxide concentrations in soil. The soybean plants exposed to nano-sized cerium oxide experienced slower growth than non-exposed plants, and at medium and higher doses, the soybean plants expressed lower levels of nitrogen fixing, which is important for plant growth.
Cerium oxide is used in ceramics and glass making and is used in lapidary as jeweler’s rouge. It is also used in the walls of self-cleaning ovens as a hydrocarbon catalyst during the high-temperature cleaning process. Zinc oxide is a common sunblock and is found in calamine lotion. Alan Tessier of the National Science Foundation, which funded the study along with the U.S. Environmental Protection Agency, commented, “If the nanomaterials tested in this paper were to move into the biosolids or irrigation system used in agriculture, they could seriously harm agricultural production.”