Extremely tiny—approximately 1/100,000th the width of a strand of human hair—nanoparticles are microscopic versions of materials. The issue is these minute versions may behave much differently in our bodies than the same substances in larger, better-studied form.
Sometimes nanoparticles occur naturally, for instance, the titanium dioxide powder used in many marshmallows, cream fillings, frostings, and confectioner's sugar products likely contains some level of nanoparticle material. But in recent years, there's been a huge push to engineer all types of nanoparticles for use in food packaging, pesticides, supplements, and even plastic beer bottles designed to protect against UV rays.
Food manufacturers sometimes add silver nanoparticles to food packaging to kill bacteria and keep foods from spoiling as quickly. Clearly, a smart business move for them, but how does it affect the consumer? "There's almost no information out there on the health effects of nanoparticles. That's really the issue here," says Phil Landrigan, MD, chair of the department of preventive medicine at Mount Sinai Medical School in New York City. "There's been billions spent on nanoparticle development for commercial use, but precious little work done on health effects."
While there's no labeling required to indicate if a food or its packaging contains nanomaterials, major food manufacturers are definitely interested in the technology. According to Food & Water Watch, a consumer group that flags potential dangers in the food system, industry giants like Nestle, Kraft, and Heinz are investing in nanoparticle research and development despite a poor understanding of health impacts.
There's some early evidence suggesting some pretty unappetizing nanoparticle news. "Because of their small size, they are likely to pass from the gut, once ingested, to blood, organs, brain, and fetal circulation," explains Jennifer Sass, senior scientist at Natural Resources Defense Council.
While some animal studies raise red flags, the truth is public health and university researchers are playing catch up, trying to study different kinds of nanoparticles in the lab, but without knowledge about secret nanoparticle-containing formulations that are going into full-scale production. What's actually being used in the real world is a bit of a mystery since industries aren't required to disclosed this due to proprietary concerns.
"Nanoparticles can be considered emerging contaminants like so many other chemicals," says William Ball, PhD, professor of environmental engineering at Johns Hopkins University. "But as we're trying to figure out their potential fate, they're already being mass produced and used in everyday products.
"Because of the complexity of the topic, it is worrisome that we don't know more details about these materials before they are launched into production," he adds. Ball studies certain nanoparticles, trying to figure out how they affect the environment and behave in water. While he doesn't want to raise unnecessary alarm, he is especially concerned about one nanoparticle trend in particular: Nanoparticles used as part of the delivery solution for pesticides. The so-called "inert ingredients" of some formulations already contain nanomaterials that could be taken up by the roots, cells, stems, and fruit of the plant.
"We're growing things on a large scale because we're trying to feed the planet, but because this is a direct application to the earth, there's the possibility of real problems for eco-systems, including uptake into food sources," he says.
Will we one day relegate nanoparticles to the legion of health and environmental disasters once considered safe? After all, smoking cigarettes and making electronics with polychlorinated biphenyls (PCBs) were both once considered safe—until we learned decades later of their potent cancer-causing properties.
Here's how to go on a nanoparticle-reducing diet:
•Eat organic. Jaydee Hanson, director for the human genetics policy at the International Center for Technology Assessment in Washington, DC, says organic foods are grown without the use of human sewage sludge, a wastewater-treatment-plant by-product that could be tainted with nanoparticles.
•Eat fewer processed foods. Because processed foods are more at risk of containing nanoparticles, learning to cook with organic, whole ingredients helps cut your nanoparticle exposure.
•Look for obvious warning signs. If food packaging is labeled as "antimicrobial" it likely contains silver or titanium nanoparticles, Hanson says.
•Grow a nanoparticle-free garden. Be sure to avoid using pressure-treated lumber if you're building raised garden beds—they likely contain nano-copper. Wood like untreated locust and cedar are naturally weather resistant.
•Dodge other potential nanoparticle threats. Nanoparticles hide out in some mineral sunscreens (look for ones with larger particles, such as the Badger line), makeup, and clothing marketed as antimicrobial or odor fighting. For more information, read The Risky Technology Creeping into Your Food and Makeup and Is Your Makeup a Dangerous Science Experiment?.