Nanosilver is not talked about with the same urgency as triclosan in soaps and toothpastes and bisphenol A in canned foods, but it may be just as worrisome, and has entered the marketplace—and our bodies, and the environment—with virtually no regulatory oversight. Measuring in the billionths of a meter, nanosilver is the metal silver on a miniscule scale—and it has been added to hundreds of consumer products for its bacteria-killing properties, including toothpastes, clothing, bras, makeup, toys and washing machines, despite the fact that initial studies have indicated its tiny size may pose serious threats both to human health and aquatic wildlife.
Making its concerns about the consequences of the antimicrobial agent public, the Natural Resources Defense Council (NRDC) filed a lawsuit on Jan. 26 in federal court seeking, according to a press release, to “block the Environmental Protection Agency from allowing nanosilver on the market without the legally-required data about its suspected harmful effects on humans and wildlife.” NRDC was prompted by a Dec. 2011 EPA decision that would allow the company HeiQ Materials “to sell nanosilver used in fabrics for the next four years as the company generates the required data on toxicity to human health and aquatic organisms.”
Studies have shown that nanosilver can enter the human body via inhalation, oral and dermal exposure and that when these particles enter the body they may be more toxic than non-nano silver because they are capable of bypassing the body’s detoxification system. Once these particles have entered the blood, they can travel to organs ranging from the liver and skin to the heart, brain and testes. Among the findings for nanosilver and human health research are the fact that these particles can induce lung damage and liver toxicity.
In its own report, the EPA notes a series of hazards associated with nanosilver, writing that inhalation of nanosilver particles has a “nearly identical” impact as inhalation of asbestos. Also, they write, citing studies from 2004, “Silver nanoparticles have been found in the blood of patients with blood diseases and in the colon of patients with colon cancer.”
When nanosilver particles wash down the drain they are too small to be captured by sewage treatment plants. Instead, they enter the ecosystem where one study with zebrafish embryos found that exposure led to death and disfigurement—including malformations of the eyes, swim bladders and tail—for the fish. One of the researchers from the University of Utah, Darin Ferguson, told Environmental Health News: “Zebrafish have similar tissues and organs to us. They don’t have lungs, but they do have a liver, kidneys and heart – though it is only two chambered – and they have a blood-brain barrier.”
In explaining the need for the lawsuit, Mae Wu, program attorney in NRDC’s health program said via the release: “EPA gave this company a four-year free pass to sell an inadequately tested product. [The agency’s] approval of nanosilver is just the most recent example in a long line of decisions that treats humans and our environment as guinea pigs for these untested pesticides.”