Stories tagged nanosilver

Nov
08
2011

Professor Richard Handy and his team of scientists at Plymouth University in the UK have discovered that nanoparticles of titanium dioxide are causing holes to form (you can call them vacuoles if you want to be fancy), and nerve cells to die, in the brains of living fish. Titanium Dioxide
Titanium DioxideCourtesy Wikimedia Commons

“Gee, that sounds bad,” you might think. “But what does that have to do with me? I can’t say I’ve ever purchased a box of titanium dioxide at the grocery store.” Nope, you haven’t. But what you have purchased at the grocery store is food with titanium dioxide in it (to make your white foods whiter), and you’ve also purchased some makeup and sunblocks made with nanoparticles of titanium dioxide. And you ate your Angel Food Cake. Or you washed the makeup off your face. Or showered after a protected day in the sun. The concern is that those titanium dioxide nanoparticles could make their way through our wastewater treatment systems and ultimately end up in our rivers and streams. And cause holey fish brains.Rainbow Trout
Rainbow TroutCourtesy Timothy Knepp - U.S. Fish and Wildlife Service

In all honesty, it’s less likely that your personal usage will be directly responsible for holey fish brains and more likely that the problem rests with the large-scale manufacturing process of these products…but you’re still a key component because you’re buying what they’re selling. And so they’re making more. And now that we’ve discovered holey fish brains as a result of exposure to an ingredient in products we’re using – what should we do? Heck, holey fish brains should be concerning enough in and of itself – but let’s just take this one step further: If that’s what happens to fish, what might happen to humans?

Luckily, some important questions and conversations have arisen in the public sphere – let’s just hope the decision-makers are listening. From Nanowerk:

“The results of Professor Handy's work and that of other researchers investigating the biological effects of nanoparticles may influence policy regulations on the environmental protection and human safety of nanomaterials.

“‘It is worrying that the effects on the fish brain caused by these nanoparticles have some parallels with other substances like mercury poisoning, and one concern is that the materials may bioaccumulate and present a progressive or persistent hazard to wildlife and to humans,’ says Professor Handy.”

A writer over at Frogheart
posed some thoughtful questions, too:

  • The statement is that nanoparticles cause brain injury in fish but the researchers mention titanium di/oxide nanoparticles only. Did they test other nanoparticles as well?
  • How did they conduct the tests?
  • Did the fish ingest titanium di/oxide from the water? From their food? From both?
  • What concentrations were they exposed to?
  • Were they in an environment similar to what they’d experience naturally? Or were they in special tanks?

Good news, frogheart! Professor Handy and his team aren’t the only scientists doing this kind of research involving nanoparticles in the environment. Duke University’s Center for the Environmental Implications of NanoTechnology (CEINT) have recently shared their work on nanosilver in the environment with NISE Net, who in turn made a fascinating 6-minute video to make it all make sense:

Does Every Silver Lining Have a Cloud? from NISE Network on Vimeo.

And I happened to sit in on a panel discussion this very morning about Nanomaterials, Toxicology, and Risk, where Shannon Hanna of the University of California Santa Barbara’s Center for Nanotechnology in Society (CNS UCSB) gave a fascinating presentation about “Impacts of Zinc Oxide Nanoparticles on the Mussel.” In it, he and his team found that chronic exposure to zinc oxide had a negative impact on growth and survival on the Mediterranean Mussel.Mediterranen Mussel
Mediterranen MusselCourtesy uncredited
Nanoparticles of zinc oxide are in a whole slew of products, including the paint on boats. Boats which tend to congregate near docks. Where mussels also like to congregate. And it turns out mussels are basically Filters of the Ocean. They accumulate metals and pollutants. And then pretty much every other thing in the ocean and around the ocean (birds, us) like to eat them. Add too much zinc oxide to the mix? Runty and short-lived mussels. Hmmmm. Anyone hungry?

The studies seem to be piling up, and it’s increasingly apparent to me that nanoparticles and environment don’t play nice. Perhaps its time to start talking seriously about regulation? What do you think?

Apr
30
2008

Will wonders never cease?: A hypochondriac surfer...
Will wonders never cease?: A hypochondriac surfer...Courtesy Rickydavid
Ironic, isn’t it? Silver kills werewolves, werewolves hate silver…and yet these ancient enemies are more alike than they ever knew.

As we all know, materials start to get a little crazy when they approach the nano scale. Try as I might to crush bacteria to death with my silverware (beats washing it), silver on the flatware scale is not a very effective antimicrobial material.

When you get down to the nano scale, however, where silver particles are just a few billionths of a meter, it’s no longer like chasing down flagellates with a spoon. Really, nothing is quite like chasing down flagellates with a spoon, but all comparison is lost in the case of nano-silver.

It has been known for years now that nanoparticles of silver are able destroy harmful bacteria. The nanoparticles generate unique chemicals, known as “highly reactive oxygen species,” which inhibit the growth of bacteria. This is great, because we all hate those harmful bacteria. Nano-silver, for instance, is already found in certain fabrics to destroy odor-causing bacteria, and some high-tech washing machines generate tiny particles of silver for essentially the same reason.

Unfortunately, it’s becoming clear that these glittery little assassins may be the enemy of all bacteria, harmful and helpful.

It’s like this: we’d all love werewolves if they just spent their days tearing apart mummies, because mummies are gross and dangerous. But when werewolves start ripping into other more beneficial monsters, like Frankensteins, well, then they tend to lose favor. Frankensteins may be gross, but they have good hearts.

These tiny silver particles, according to researchers at the University of Missouri, have been ripping into Frankensteins. It’s been observed that nano-silver kills off beneficial, benign bacteria, like that used for wastewater treatment. As consumer use of nano-incorporating products increases, so to will the amount of artificial nano particles in the waste stream. Eventually this could kill off vital microbial species in rivers, streams, and lakes, as well as those used in wastewater treatment. There may be indirect consequences as well—for instance, the “sludge” byproduct of wastewater treatment is frequently used as land-application fertilizer. If silver nanoparticles accumulate in high enough levels in this sludge, they could end up seriously damaging the soil we use to grow our food crops.

This isn’t to say that we should necessarily halt our use of nano products, but it’s a reminder of how little we still know about nanotechnology. While we’ve had hundreds of years to learn to learn the ins and outs of deal with werewolves, nanotechnology is still pretty mysterious.

The University of Missouri will soon be launching a second study to determine the levels at which silver nanoparticles become toxic, and to exactly what extent they harm microbes in wastewater.

Nov
27
2006

Robin Low: What will he think about new regulations?  Robin Low makes textiles using nanotechnology.  Ask him what he thinks about these new regulations.
Robin Low: What will he think about new regulations? Robin Low makes textiles using nanotechnology. Ask him what he thinks about these new regulations.

Nanotechnology research is kicking into full gear the world over but almost everyone agrees that we simply don't know how to properly regulate its use. What will particles billions of times smaller than a meter do to our bodies and the environment? Well...they might cure our cancers and clean up our water. But they also might penetrate our blood brain barriers and stick in our gray matter or cause ecosystems to decline due to tiny tiny pollutants.

EPA takes a step in the right direction

Well, at least our government is beginning to look at this stuff. The EPA announced on Thursday that they will be regulating all use of nano-silver in US commercial products. If you make odor eating socks with nano-silver you now have to make sure that it won't get out into the environment and cause harm.

The city of Berkeley, California is also looking at creating the first local government nanotech regulations. This isn't surprising for two reasons.

  1. Berkeley has long history of being environmentally conscious and has a very active political community, often leading detractors and jokesters to dub this enclave The Socialist Republik of Berkeley
  2. They actually play host to a great deal of research into nanotechnology at UC Berkeley and the Lawrence Berkeley National Laboratory. They have a vested interest in protecting their communities from the potential harmful effects of nanotech research.

I will be watching this closely and hope that the concerned community members and the scientists can come to some middle ground where research isn't totally crippled by massive regulation but where unknown safety risks are considered.

Fun times in the nanoworld.