The manufacturing of nanomaterials has been steadily¹ on the rise in the medical, industrial, and scientific fields. Nanomaterials are materials that are engineered to have dimensions less than 100 nanometers and have very unique properties as a result of their small size. In a study funded by the U.S. Environmental Protection Agency, a team of scientists from the University of Kentucky determined² that earthworms（蚯蚓） could absorb copper³ nanoparticles present in soil.

One crucial（重要的，决定性的） step in determining the uptake（摄取，领会） of nanomaterials was discerning（辨别） whether uptake of metal ions was released from the nanomaterials or the nanomaterials themselves. Using x-ray analysis, researchers were able to differentiate⁴ between copper ions and copper nanoparticles by examining the oxidation state（氧化态） of copper in the earthworm tissues.

Many products will release their nanomaterials either as a result of regular use or after disposal. These discarded nanoparticles could enter waterways and eventually soil. According to the authors, it is unclear how nanomaterials interact in the environment due to lack of scientific research; however, there is a possibility of unintentional ingestion（摄取，吸收） by humans and animals.

Jason Unrine, the lead author of the study said, "This was one of the first studies to demonstrate that engineered nanomaterials can be taken up from the soil by soil organisms and enter food chains, and it has significant implications in terms of potential exposure to nanomaterials for both humans and ecological⁵ receptor species."

Unrine assures that ongoing⁶ studies are being conducted on transformation⁷, bioavailability（生物利用度） , trophic transfer, and adverse⁸ effects of engineered nanomaterials in terrestrial ecosystems⁹.

Nanomaterials are used in a variety of instruments and consumer goods including protective coatings and solar cells.