Way back in 2008, the Center for Food Safety and several other nonprofits petitioned the EPA to start regulating the use of nanosilver, which may be considered a pesticide due to its antimicrobial properties.
While the risks of nano-silver to the environment and human health are not well understood, existing studies have indicated cause for concern, such as harmful impacts on fish and aquatic ecosystems, potential interference with beneficial bacteria in our bodies and the environment, and the potential development of more virulent harmful bacteria.
They simply wanted it to be regulated like any other pesticide. Not to much to ask for, right?
Well, the EPA did publish a lengthy report in 2010, and while its authors noted the need for more and better research, they did find some reason for caution.
There is evidence that silver, and in particular nanosilver, is toxic to aquatic and terrestrial organisms, a variety of mammalian cells in vitro, and may be detrimental to human health. While undoubtedly silver and nanosilver have useful applications in the medical arena (for instance as coatings for medical devices or as wound care for severe burns victims), their use may need to be strictly controlled. Bacterial resistance to antibiotics is an ever increasing problem globally, and indiscriminate use of biocidal silver in numerous consumer products is not only unnecessary, but may further increase bacterial resistance to a dangerous level (Mühling et al., 2009). There are preliminary indications that in nanoparticle form, the toxicity of ionic silver may be increased, or that the nanoparticles may exert their own toxicity. The disposal of biocidal silver products into wastewater raises a number of concerns as
the resulting sewage sludge may be used on agricultural soils, disposed as solid waste in landfills or be incinerated. Biocidal silver may also disrupt the functioning of key soil microbial communities.
Despite this, the agency chose to fast track approval of a variety of nanosilver products for widespread use. Two of these were later overturned by a federal appeals court, “ruling that the EPA had incorrectly found they posed no risks to toddlers”
Hence, the current lawsuit against the EPA for failing to adequately respond to the nonprofits’ original petition.
“It’s unfortunate,” says Jay Feldman, executive director of Beyond Pesticides, “that it takes a lawsuit to get EPA to carry out its responsibility to regulate nano-silver for its toxic pesticidal properties and broad exposure patterns through consumer and personal care products. Like any toxic pesticide, nano-silver must be subject to the full force of the law and label restrictions intended to protect people’s health and the environment.”
As we noted before, the fact that there’s so much we don’t know about about nanosilver is just as troubling as what we do know. Research presented at last year’s TechConnect World Innovation Conference and Expo showed that nanoparticles do get released from plastics. A study in Nanotoxicology found that ingested nanosilver can damage DNA in multiple tissues in mice.
Nanosilver has already been found aggregating in wastewater and landfills – pollution that has been found to harm ecosystems.
What harms ecosystems ultimately can do harm to us, as well. Will it? That, we don’t know yet. The technology is that new.
Just last week, we ran across a fascinating article on the use of nanosilver pesticides in farming. Food would be in an even more direct line of exposure. There are more questions than answers about the possible consequences.
As the manager of one nanotech toxicology lab put it, “The environmental fate of nanopesticides is a big, black hole.”
Image via Nanotechnology Now