If you stand out in a windstorm and blowing dust passes over your skin, you’re not likely to get hurt. Open your eyes, however, and some of the small particles could get inside, causing tears, redness, and irritation. Breathe in, and some of those pieces of dust could get into your throat and lungs, causing coughing, sneezing, and even wheezing.
Whether something can penetrate our bodies and get inside to where they could actually cause damage has been the source of debate around “nanoparticles.” These microscopic particles have a diameter of only one to 100 “nanometers”—about 1/8000of the width of a human hair.
Scientists are excited about these tiny materials because of their potential in improving medical care, water purification systems, energy systems, and more. Yet this is a new area of scientific research, and we don’t yet know all the potential risks.
Here’s more about nanotechnology, and why you may want to avoid nanoparticles in your skin care and foods.
The Potential Benefits of Nanoparticles
Delivering “super drugs” is one area of medicine that may benefit from the use of nanoparticles. A 2005 study, for example, found that nanoparticle-based drug delivery systems helped treat tuberculosis. A 2014 study found that nanoparticles could carry a specific ration of three cancer drugs and release them as designed at the specific target, minimizing side effects.
Because of their super small size, nanoparticles may also prove beneficial in the energy industry. They may allow us to build smaller and more efficient batteries, fuel cells, and solar cells. They may help us to make stronger, more durable products in the manufacturing industry, and hold a lot of potential in improving computers and plasma displays. All these changes could help make products cheaper, smaller, or more efficient in one way or another.
But as with any new development, nanoparticles present certain risks, as well. These include health and environmental risks that could have lasting impacts.
Nanoparticles in Personal Care Products
The health concern with nanoparticles is that the materials are small enough to penetrate the skin or to get inside the body via inhalation—when they’re not intended to do so. Once inside of us, they could cause problems.
A recent study, for example, found that certain nanoparticles can harm DNA. Researchers from MIT and the Harvard School of Public Health looked at five types of nanoparticles—silver, zinc oxide, iron oxide, cerium oxide, and silicon dioxide. All of these are present in personal care products, toys, clothing, and the like, helping to improve texture, kill microbes, and enhance shelf life.
Most of the time, these materials are too big to penetrate the skin or to be inhaled, but when they exist as nanoparticles, they have different physical, chemical and biological properties. For one, they can penetrate our body’s cells more easily.
Zinc oxide, for instance—which is considered the safest sunscreen and has been recommended for use in children because of its stellar safety record—when present in nanoparticles, was found in this study to produce free radicals, which can damage DNA and lead to disease. The other concern is that nanoparticles may accumulate in tissues over time, leading to more serious potential health issues.
Researchers noted that more studies are necessary before we can say for sure what these nanoparticles may do in personal care products. One of the questions concerns dose. Just like a little aspirin will help your aches and pains but a lot could damage your stomach, scientists imagine that low levels of nanoparticles may not cause harm, but that higher levels will—especially considering how often we all use personal products every day.
The Question of Sunscreens
Sunscreens are a particular area of concern, as making ingredients smaller makes them less visible on skin. (Remember how zinc oxide used to look white? Smaller particles now make it less visible.) Some products use “micronized” particles, which are small but still cannot penetrate skin. Nanoparticles, however, are a different story.
A 2012 study also suggested that even so-called “physical sunscreens” like zinc oxide and titanium dioxide—considered to be safer than chemical sunscreens—when present in such small particles, could potentially penetrate skin and potentially increase free radical activity. Missouri University researchers conducted laboratory studies on nanoparticles of zinc oxide and found that they underwent a chemical reaction that released unstable and damaging free radicals. (Similar studies have found the same results with titanium dioxide.)
There’s still a lot of debate on the issue, as some studies have shown the opposite. A 2011 study, for instance, found that ultra-tiny zinc oxide particles did not penetrate beneath the outermost layer of skin cells, so would be unlikely to increase free radical damage. An earlier 2009 study showed similar results, as did a 2007 study. For now, however, it’s best to be cautious, and avoid nanoparticles in sunscreens. (Check with the manufacturer—most say “made without nanoparticles” or something similar if they avoid these ingredients.)
Other cosmetics, too, can present dangers when they contain nanoparticles. A 2012 study, for instance, found that nanoparticles in cosmetic powders could contaminate the lungs, potentially leading to health effects.
Nanoparticles in Food
Nanoparticles are also already appearing in our food supply. They are used as preservatives, to keep foods fresh and bacteria-free for longer, and to act as thickening and coloring agents. Unfortunately, because the science is new, companies aren’t yet required to reveal nano-sized ingredients on the label. (We hope that changes soon as new research comes to light illuminating the potential dangers.)
According to news reports, nanoparticles are present in gums, mints, candies, frostings, Pop Tarts, coffee creamers, puddings, vitamins, and more. We have little science on how these particles may affect health once their inside our bodies, but in an animal study from Cornell University, scientists discovered that after eating the nanoparticles, chickens experienced a change in the structure of the lining of their intestinal walls. Scientists said the results showed that nanoparticles could cause subtle changes that could lead to health problems down the road—such as the overabsorption of other, harmful compounds.
News about nanoparticles in the food supply is still new, and many consumers are still unaware of the potential risks. As with genetically modified organisms, it seems the industry is being allowed to use the new technology without testing it first, subjecting us all to a giant science experiment with the results still unknown.
Nanoparticles and the Environment
Because of their super small size, nanoparticles can slip through wastewater treatment plants and survive to take up residence in our rivers, streams, and other waterways, as well as in our soils. In August 2012, scientists found that soybean plants absorbed zinc oxide nanoparticles from sunscreens, cosmetics, and lotions into their leaves, stems, and beans.
A 2011 animal study discovered that silver nanoparticles, when inhaled, caused lung toxicity and inflammation. Copper nanoparticles increased risk of pulmonary infections. Earlier 2008 research showed that carbon nanoparticles (used in plastics and computer chips) could damage the lungs in a way similar to that of asbestos, potentially leading to an increased risk in lung cancer.
Research in 2012 also found that silver nanoparticles, which are used as preservatives, could easily migrate to plants, insects, and fish, potentially disrupting ecosystems. These nanoparticles also reacted and changed when they made their way into the environment—only 18 percent remained in their original form. Silver was detected even in plants that started growing 6 months after the study.
So far, the government regulates nanoparticles the same way they do other sizes of a material—silver nanoparticles are regulated the same as any other type of silver, for example. But studies show the things just aren’t the same, and are not even governed by the same physical laws as larger particles, but by quantum mechanics. That means their ability to react, chemically, and produce potential toxicity is likely to be different from the source material, and is still largely unknown.
What To Do?
For now, we consumers are left largely in the dark when it comes to knowing whether or not nanoparticles are in our products. (Incidentally, the European Food Safety Authority requires that foods containing nanoparticles be labeled. The FDA does not require this of food manufacturers in America.)
We can take some of the precautions below. Beyond that, the best bet is to continue to spread the word, buy from conscientious companies who are willing to disclose their use (or non-use) of nanoparticles, and continue to support legislation that strives for complete and honest disclosure of ingredients in all our products.
- Check your product against the list at the Woodrow Wilson International Center for Scholars’ Project on Emerging Nanotechnologies, which identifies which products, including foods and supplements, contain nanomaterials. The list is far from comprehensive, but does give us a place to start.
- Choose locally grown fresh foods as often as possible. Cut back on packaged and processed foods, in which nanoparticles are more likely to be present.
- Choose organic whenever possible.
- Avoid GMO foods.
- Use natural and safe cosmetic products (especially those that stay on your skin, like sunscreens, moisturizers, and makeup) that do not include nanoparticles in their formulas. Check your products against the Skin Deep Database for more information on any potential nanoparticles.
- Watch out for words like “nanodelivery system” which indicates the presence of nanoparticles, but remember that companies are not required to reveal nanoparticles on labels.
What do you think of nanoparticles in our foods, cosmetics, and the environment? Will you take steps to protect your family?
Brita Belli, “Eating Nano,” E Magazine, November 1, 2012, http://www.emagazine.com/magazine/eating-nano.
Twilight Greenaway, “Nanoparticles in your food? You’re already eating them,” Grist, December 3, 2012, http://grist.org/food/nanoparticles-in-your-food-youre-already-eating-them/.
“Nanoparticles in our Food?” Eat Local Grown, http://eatlocalgrown.com/article/11419-nanoparticles-in-our-food.html.
“Slipping Through the Cracks: An Issue Brief on Nanoparticles in Foods,” As You Sow, http://www.asyousow.org/health_safety/nanoissuebrief.shtml.