In one new experiment, Furgeson, a professor of pharmaceutical sciences, exposed zebrafish embryos to silver nanoparticles in a laboratory, and found that some died and others were left with dramatic mutations.
“Some of the fish became extremely distorted, almost making a number nine or a comma instead of a linear fish,” he said.
The nanosilver caused malformations in their eyes, swim bladders, tails, and some embryos developed fluid around the heart that causes congestive heart failure, according to the study, which was published in August in the nanotechnology journal Small.
Furgeson tested concentrations until he found one that wasn’t lethal, about 0.01 grams per liter, to observe what nanosilver would do at doses that didn’t kill the embryos.
Scientists do not yet understand what this toxicity means to humans and the environment. Testing silver nanoparticles on fish and other organisms is an important step toward understanding how they will interact in the human body. It is unclear if these nanoparticles will accumulate in specific organs or what kind of damage they could cause.
“Zebrafish have similar tissues and organs to us,” Furgeson said. “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.”
Raising concerns about potential harm to human health, other recent research has shown that some metal nanoparticles can damage DNA or kill cells. One new study found that nanoscale particles can cross into the womb through the placenta.
Different materials have different effects, according to the fish study. Both gold and silver nanoparticles were tested, but only the silver ones were toxic to the fish embryos in all sizes, according to the study. Gold particles did not have an effect. Other studies suggest that copper nanomaterials are toxic to rats.
“Chemical composition of the nanoparticle is as, if not more, important at inducing toxicity,” the authors said in their report.
Furgeson and his colleagues said that zebrafish could be used to identify “nanomaterial characteristics that afford minimal or no toxicity and guide more rational designs of materials on the nanoscale.”
Silver is one of the most toxic heavy metals. In the 1970s, ionic silver from wastewater polluted San Francisco Bay at concentrations that prevented the mussels from reproducing. Changes in wastewater treatment have decreased the concentrations substantially.
“The silver that went into wastewaters when millions of people had their photographs developed taught us that small additions of silver to the environment make a big difference,” said Dr. Samuel Luoma, a former U.S. Geological Survey senior researcher who was lead author of a report by the Project on Emerging Nanotechnologies. The project is a partnership of industry, government and scientists established by the Woodrow Wilson International Center for Scholars and the Pew Charitable Trusts.
“We have no means of detecting nanosilver in the environment once it is released, even if concentrations rise to levels that are toxic to aquatic ecosystems,” Luoma said in a statement when the report, “Nanoscale Silver: No Silver Lining?” was released last year.
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5 Comments
Add CommentEvolution will take care of this, but we may not like the results.
Reply | Report Abuse | Link to thisThank you for scientifically verifying the effectiveness of colloidal silver "tiny particles of silver - potent anti-microbial agents that can kill bacteria on contact". It is nice to see a verification of Alternative Medicine in the writings of Scientific American. Now if we can get the FDA and AMA to recognize it we may finally be able to rid ourselves of "super bugs" that develop resistance to Big Pharma's anti-biotics. Sure it is not as profitable but we will be a lot healthier for it.
Reply | Report Abuse | Link to thisColloidal silver does not harm the helpful micro flora of the gut and no microbe can develop a resistance to it. Anti-biotics are indiscriminant killers that kill the good and the bad and the ugly allowing harmful yeast and fungi to overtake the body (cancer). The toxins in the feces and other offal of yeast and fungi cause a host of symptoms that mimic many diseases causing people to burden the health care system looking for a cure. They take up the doctor's time and they spend a lot of money on Drugs that do not cure the problem but only make it worse. Of course, Big Pharma loves this and they help perpetuate it.
Nano particles of silver and many other minerals have always been a part of the make-up of sea water. They are called trace elements and we need them to maintain healthy bodies. Trace elements are what are lacking in our food supply as chemical fertilizers, herbicides and pesticides deplete the soil of the elements we need for health. A lot of the increase in diabetes, heart disease, arthritis, arteriosclerosis, obesity and a host of other "modern illnesses" have their roots (literally) in depleted trace elements in the soil. Farmers used to grind stones to spread on their fields to maintain healthy levels of trace elements in their soils. We need to restore our soil if we ever hope to restore health in our people. This alone would do a lot more for healthcare in America than any bill Congress could conjure up.
I agree. A lot of the nano technology as well as genetic manipulation (Monsanto et al) that is going on is very unhealthy to all of life on this planet. Cross breeding plants to create a more productive and healthier plant is one thing; genetically manipulating the makeup of a plant is another. Our bodies evolved along with other life forms on this planet in a symbiosis and introducing strange nanobots and gmo's into the equation throws the whole system out of balance. And that, my friend, is a recipe for disaster.
I love reading Scientific Word Salad like the above alternative medicine diatribe. It's like a big verbal burp. Try thinking about it as you read it, and you'll realize it's just scary BS to make you buy the latest fad medicine.
Reply | Report Abuse | Link to thisWow, this is great information. I strongly believe that as a pet owner, you should be aware of issues that could be potentially harmful for your pet. Dog owners should know about the parvovirus (http://earlydetectpet.net), and fish owners should know about nanosilver.
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Reply | Report Abuse | Link to thisSilver is one of the most toxic heavy metals. The EPA has no know toxic listing for silver! Going the give the Earth a citation for making colloidal silver? its all around us in nature! If I put drops of bleach in a fish take till they die going to stop making bleach?