Post-consumer nanomaterials stunt plant growth, researchers find
Scientists at the University of Kentucky and their international colleagues determined that the metal in nanomaterials is harmful to microorganisms as well as plant life.
From face to farm
The researchers looked at nanosilver, nanotitanium dioxide and nanozinc oxide as it turns up in the by-products of water treatment systems and are then conventionally used as agricultural fertilizers. “About half of the biosolids produced in the U.S. and parts of Europe are used as soil amendments on agricultural and other lands and have been for many decades,” reports Katie Pratt in an item for phys.org.
“Biosolids can provide needed nutrients and organic matter to the soil. In the United States, the U.S. Environmental Protection Agency regulates biosolids used as fertilizers.” This is the route by which the post-consumer nanomaterials are getting to the ecosystem.
Seeing results
The study documents two consequences of the nanoparticles. Researchers looked at what happens to legumes, soil microorganisms, and nitrogen-fixing bacteria that are exposed to biosolids containing nanosilver, nanotitanium dioxide and nanozinc oxide.
“They found that the biosolids with nanomaterials prevented the colonization of plants by nitrogen-fixing bacteria and changed the composition of microorganisms in the soil,” explains phys.org. Therefore plants were underdeveloped and took up significantly more zinc than plants exposed to biosolids without nanometals.
The scientists also explored how nanomaterials affect the molecular mechanisms of plants and bacteria. And, they found that the gene expression of the plants exposed to nanometals was markedly altered.
Early opportunity
Engineered nanomaterials outlive the products they are made for and are beginning to affect the environment. (Research on the longer-term impacts of nano on human health, likely looms large as well.)
The University of Kentucky team, for instance, used a pilot water treatment system and fabricated biosolids for their tests. So there is time here for a personal care industry leader to self-regulate nanoingredients and set themselves apart by establishing a responsible standard for nano in personal care.
Collective wisdom
The National Institute of Standards and Technology has begun building an online resource for environment, health, and safety researchers that sets out best practices for testing the characteristics and hazards of nanoingredients. The initial batch of 13 testing protocols will be expanded as more tests are proffered by scientists in the field and validated by the institute.
