Have you noticed that many pacifiers contain nanoparticles of silver these days, and is that good? The manufacturers tell us this process makes the pacifier anti-bacterial, but why not just rinse it with soap and water?
What, come to think of it, are nanoparticles?
Manmade nanoparticles are groups of atoms manufactured from atoms in other materials, mainly carbon and metals, arranged into a new product, and characterized by their fantastically small size. They are between 1 nanometer and 100 nanometers in size (in at least one dimension), that is, between one and 100 billionths of a meter. To give you an idea of how small that is, it would take eight hundred 100 nanometer-size particles side by side to match the width of a human hair. (The definition is still in flux. Particles up to 300nm in one dimension can also be called nanomaterials and can also have toxic properties.) Nanomaterials can be seen only with powerful microscopes.
The really essential point is, that they have unique chemical properties that differ from the properties of their larger scaled components.
Let’s get to the bottom line right here and now: products with nano ingredients are increasingly used in electronics, medicine, personal care products (even ones labeled as ‘organic’) and many other applications. The food and agricultural industries are using nanotechnologies to manufacture foods, food packaging, more potent pesticides, and more. A European report says these uses are “bringing in a fortune” to their manufacturers.(1)
But none of the uses have been proved safe. I wouldn’t stick a silverized pacificer in my grandchild’s mouth nor clothe him in nano-impregnated clothing. At least, not now.
No one knows just what these particles can do to humans, especially to children, nor to plants or wildlife, but what we do know so far is not reassuring. As consumers and parents, we are at a disadvantage because manufacturers do not have to disclose the use of nanoparticles on product labels (see below for help with that). Furthermore, there’s no one in the world regulating the manufacture or use of nanomaterials; nor is any public agency tracking them, so it’s virtually impossible to find out how many “nano” consumer products are on the market and which merchandise could be called “nano.”
Hundreds of nano products (as far as anyone can tell) are made from silver, which has anti-bacterial properties. Nanosilver has been incorporated into socks, tee shirts, underpants and other clothing, manufactured mainly in China, South Korea and other Asian countries - then marketed as germ-killing and odor-free. It’s also been added to toothpastes, shampoos, cosmetics, deodorants and sunscreen (allowing the chemicals to penetrate the skin more easily). And coated onto computer keyboards and mousse; added to toothbrushes, food storage containers, lightswitches. No one knows how much nanosilver is now in use.
In fact, because of its antibacterial properties, nanosilver should already be a regulated product. Silver itself, more toxic to aquatic plants and animals than any metal except mercury, is classified as an environmental hazard by EPA, and, silver nanomaterials (because of their higher surface area) release their toxic silver ions more readily than the larger forms (2) A drop of nanosilver has the polluting strength of a ton of silver. Fabrics laced with silver nanoparticles release those particles when the fabric is exposed to artificial human sweat, one study showed.(3) . EPA has not yet figured out what to do though the agency is proposing to grant conditional approval to a pesticide containing nanosilver.
Research has shown that nanoparticles can penetrate into places larger particles cannot go, such as through our “blood-brain barrier” which would otherwise stop toxic molecules passing from the blood into the brain. The particles also find their way into vital organs including the kidneys and liver, but precisely what they do to them has yet to be fully investigated. Researchers in the United Kingdom have found some nanoparticles in common household items can damage DNA without even penetrating the cells (the nanoparticles transmit signals through a protective barrier of human tissue and indirectly damage DNA inside cells).(4) Worms fed gold nanoparticles have up 90 percent fewer offspring.(5)
Once released from the product they were in, silver (and gold) nanoparticles, like all waste, first end up in your city’s sewage. There they inhibit the break-down of other waste products. And this throws into doubt the ability of cities, like San Francisco, to make “organic” compost out of sewage sludge.
The silver nano particles are non-biodegradable, so they cannot be removed but continue to circulate and accumulate over time in organisms, including humans. When the nanoparticles reach waterways, they are highly toxic to fish and the aquatic ecosystem. Gold nanomaterials are similar killers.(6).
The nanoparticles used in sunscreen, as well as in food coloring, paint, and other consumer products, are derived from titanium dioxide, the most common nanomaterial used in consumer products today. The few studies done so far indicate that fetal exposure, through the mother, alters the way genes involved in brain development express themselves (that is, how those genes turn on or off, to do what they’re supposed to or not). (7)
Manufacturers are now nanosizing lead and cadmium, two metals notoriously toxic and, when nanaosized, incredibly more dangerous. But the manufacturers will not disclose what products they aim to use these materials for.
What about the future, then? Most likely, some nano applications will be helpful, perhaps even miraculous, especially in the field of medicine. For example, the most harmful side effects of today’s treatments such as chemotherapy are a result of drug delivery methods that don’t pinpoint their intended target cells accurately. Researchers at Harvard and MIT are experimenting with using nanoparticles to deliver cancer treatments that target only the tumor without damaging normal tissue.
Perhaps the future will bring a “green nano technology.“ For example, a Maryland-based company is trying to make the world’s smallest organic solar cells that could be sprayed onto glass where they’d generate electricity.(8) A Kansas university is trying to develop a nanocrystalline powder that could theoretically absorb toxic air-borne particles.(9) Companies claim these technologies will be safe but no regulation yet exists to substantiate such claims. Not to mention that nanomaterials take huge amounts of energy to produce and throw off toxins during their production. (10)
If and when the law that’s supposed to protect us from all manmade chemicals, the Toxic Substances Control Act, ever comes up for the improvement it desperately needs, new rules for nanomaterials will have to be included. The industry is of course gearing up to resist regulation as “increasingly difficult and far more costly.”(11)
For now, here’s a story with a moral: Samsung manufactures a line of silver nano-coated washing machines called “Silver Care,” capable of removing 99.9 percent of the bacteria in a load of laundry. These machines release 400 billion nano-sized silver ions in each load. When a different manufacturer looked into the usefulness of nanosilver in washing machines compared to regular washing machine technology, they found that washing clothes at 20C (68F) with detergent removed 99.79 percent of bacteria.(12) Thus, they determined, using nanosilver was not worth the environmental cost.
So if the benefit is, for now, minimal, and the health risks are substantial, the conclusion of one of the nation’s lead environmental health scientists, Dr. Jen Sass of the Natural Resources Defense Council, makes sense: “Things that are in the nanoscale that are intentionally designed to be put into consumer products should be instantly required to be tested, and until proper risk assessments are done, they shouldn’t be allowed to be sold.”(13)
Resources for Parents
To identify products with nanomaterials:
While not comprehensive, this inventory gives the public the best available look at the 1,000+ manufacturer-identified nanotechnology-based consumer products currently on the market. You can browse products by name, category, company, or country. (This is a project of the Pew Charitable Trusts and the Woodrow Wilson Intl Center for Scholars.)
If you have questions about a product not on that inventory, try to phone the manufacturer.
For a guide to sunscreens without nano ingredients:
To follow citizen-based research and actions:
Nanotechnology Citizen Engagement Organization.
Friends of the Earth Australia
For information on the effect of nanoparticles on women’s reproductive health:
Ask for a copy of the study from the University of California at San Francisco:
— - - - - - - - - - - - - -
1. “ The Bund opens a database with over 200 nanoproducts.” The Organization for the Environment and Protection of Nature press release, December 14, 2010
4. Nanoparticles can cause DNA damage across a cellular barrier,“ Gevdeep Bhabra et al, Nature Nanotechnology 4, pp 876 – 883, November 5, 2009
5. Laura Cassiday, “Nanoparticles Worm Their Way Into The Food Web,” Chemical & Engineering News, October 7, 2010
6. Heather Hamlin, “Silver is a potent nerve cell toxicant,” Environmental Health News, January 21, 2010
7. “Maternal exposure to nanoparticulate titanium dioxide during the prenatal period alters gene expression related to brain development in the mouse,“ Midori Shimizu, et al, Particle and Fiber Toxicolology July 29, 2009
13. communication with author
Alice Shabecoff is the co-author of Poisoned for Profit: How Toxins Are Making Our Children Chronically Ill. The book includes guidance for parents on how to reduce risks for the children and how to change the system that allows these toxins in our children’s daily lives.