In a greenhouse next to the University of Kentucky's Agricultural Science Center North on South Limestone, hornworms noshed happily on plants sitting in a water-based solution. What the worms did next with their digested leaf lunch has made an impression on a scientific world that is trying hard to stay ahead of its own progress.
The worms failed to excrete the atom-size particles that had been suspended in the water and drawn through the roots of the plant. The particles, purposely made to be easily traceable, were found to have made their way into the tissues of the worms at an even greater concentration than they been in the plant the worms had eaten.
To the untrained observer, that might not mean much. To Paul Bertsch, professor of environmental chemistry and toxicology at UK and his team of researchers, it was a surprise.
That's because Bertsch's work includes atom-size particles — they're called nanomaterials, and they're being used in revolutionary technologies for everything from face cream to odorless socks, from hockey sticks to drug-delivery systems — and is the red flag the science community has been looking for to get more regulation and more testing before wholesale commercialization of nanotechnology gets ahead of the ability to manage it.
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Here's what the study with the worms told Bertsch: The stuff that sock manufacturers are putting in your odorless socks to take the stink off could end up on your table inside the turkey, the dressing and the green beans laid out for Thanksgiving dinner.
There is plenty of time to make sure that doesn't happen, says Bertsch, "if research informs policy which is based upon results not perceptions or fear."
The red flags have clearly been seen. Within weeks of the two studies being published, word was traveling from highly regarded peer-reviewed journals, Environmental Science & Technology and Nature and Nanotechnology, to more general-interest science blogs like Wired Science. Journalists from as far away as India have requested a bit of Bertsch's time to explain his study's implications.
So what is nanotechnology? It refers to working with matter at the scale of one billionth of a meter, or less than one-100,000th the width of a human hair. A nanometer, for example, is a millionth of a millimeter. An inch contains 25,400,000 nanometers; a sheet of paper is about 100,000 nanometers thick. The particles ingested by Bertsch's worms were 5 to 15 nanometers thick.
Nanoscience involves researchers finding new ways to build from the atomic and molecular levels to create materials with new properties and new jobs never fully imagined before. The field is opening up new avenues of energy efficiency, medical drug-delivery, electronic switching and mechanical strength technologies.
The National Science Foundation predicts nanotechnoloy will be a $1 trillion industry in less than four years and transform every aspect of our lives. So fast is its application of nanotechnology growing, says Bertsch, that there were 1,500 consumer products using it in 2010. That compares to 54 in 2005. Uses include cosmetics, sunscreen, tennis rackets, sunglasses and those anti-microbial, water-repellent socks..
And most of those new products are good uses of the technology, but it's what Bertsch's worms did that troubles a few.
Take those socks, for example. At least four companies make odor-eliminating socks using nanotechnology, according to the Nanotechnology Project product index. Those socks could potentially shed the anti-bacterial nanoelement into the water of your washing machine. That could be a problem when your washing machine's waste water empties into the public sewer system. No sewer system is equipped with a filter that can catch these nanoparticles. The nanoparticles then become part of the biosludge that eventually could be spread as landscape fertilizer.
That fertilizer can leach chemicals into the water system, and those can be drawn into the roots of crops, much like the roots of the plants used in Bertsch's study. Many questions immediately arise: Do the crops now biomagnify the nanomaterial? Are we in any danger? And of what?
"It's a very, very interesting piece of work," says R. David Holbrook, a chemical and environmental engineer at the National Institute of Standards and Technology in Maryland. "This is a science in its infancy. (Bertsch's team) is the first to see how these nanomaterials can accumulate to a large degree in a terrestrial organism. It's important in that it says there is a really good chance now to get the process right — not to say this is really dangerous — but to be sure we do the science upfront so we don't have to go back in 10 or 20 years, like we did with DDT."
DDT is a synthetic pesticide that was used heavily in the 1940s and 1950s, until scientists began to realize it seriously harmed the environment, particularly birds, and posed a significant danger to human health.
Bertsch chairs the U.S. National Committee for Soil Science at the National Academy of Science and serves as director of UK's Tracy Farmer Institute for Sustainability and the Environment. He's in a perfect position to address these issues.
He also leads the Transatlantic Initiative for Nanotechnology and the Environment, a $4 million joint grant from the U.S. Environmental Protection Agency and the United Kingdom's Environmental Nanoscience Institute. That group is studying how certain nanomaterials in wastewater management systems are taken up by wheat crops, analyzing the percentage of biomagnification in harvestable grain.
"The more we talk about what is hazardous," says Bertsch, "the more we can talk about what we can be doing to create and synthesize what is not hazardous. As we generate more and more information about designing these materials, the more specific the engineering of these materials can be."