(NHI Nanoblog) How are super-small engineered particles impacting plants and the food chain for humans and animals?
As with most potential hazards involving nanotechnology, it’s too soon to tell, according to a new study.
Journal of Agricultural and Food Chemistry Image
At left, a plant showing the selective uptake and translocation of nanoparticles; at right, a cross section of the root structure, showing how different substancesreact.
The paper, by researchers at the University of Texas at El Paso, is a review of existing studies on how ultra-tiny “nanoparticles” of often-common substances interact with plants, including crops grown for food. They found that plant responses to many nano-sized substances, such as carbon nanotubes, titanium dioxide and zinc oxide, are “not well understood.”
The lack of clarity has wide implications, the authors write, because of the possibility of multi-generational changes to plants, among other issues. Another is the possibility of “biomagnification,” in which a relatively small concentration of a dangerous substance gets bigger as it moves up the good chain (think DDT and bald eagles).
Nanotechnology leverages super-small particles (a nanometer is a billionth of a meter) to create products with amazing properties. These materials can make better batteries or lighter and stronger bike frames, as well as new medical instruments and medicines that can save lives.
These “nanomaterials” are believed to hold great promise for a wide variety of applications. But shrinking these substances can change their properties, and scientists are struggling to figure out whether, how and why that shift can make them dangerous in the process.
It’s no surprise that this paper shows there’s a big gap between what scientists would like to know and what they do know. But as with other pieces of the nano puzzle, it’s troubling from a scientific perspective, as well as a practical one: a growing number of consumer products contain nanoparticles, some of which are known to be turning up in water and soil.
If the titanium dioxide from your sunscreen, or nanosilver from your anti-microbial gym socks, can go from the water to the food you’re eating, it raises a whole host of other questions.
The paper, written by Cyren M. Rico, Sanghamitra Majumdar, Maria Duarte-Gardea, Jose R. Peralta-Videa, and Jorge L. Gardea-Torresdey, was recently published by the Journal of Agricultural and Food Chemistry.