The Silver Nano Particle Controversy
By: Oliver Truesdale
Nanoparticles are small particles that easy to incorporate into products as well as our bodies. Measuring approximately one billionth of a meter, nanoparticles are 3,000 times smaller than the diameter of human hair.
By nature, nanoparticles are made up of different properties than the essential bulk material they come from, but are able to perform functions inherent in the original compound. In the case of silver nanoparticles, the compound is considered to be both an antibacterial and an antiviral.
Silver has been used in the medicinal field since antiquity, and most recently in colloidal form, which has proven extremely effective against a wide range of pathogens. Low doses of colloidal silver are being used as a probiotic for treatment of many ailments including intestinal problems as well as for HIV and AIDS. Commercially, nanosilver is being incorporated in many products in order to kill bacteria such as odor-control clothing, detergents, cutting boards, and countertops.
Right now there is a huge controversy going on regarding the ethics of using nanosilver in its relation to environmental pollution. A research study funded by Purdue University on the effects of nanosilver in the water supply concludes that it can be toxic to aquatic life. Tested on fathead minnows, nanosilver suspended in a solution was used to determine what repercussions there might be for fish and other water dwellers. The minnows were tested from the embryonic stage to the moment when they swim to the surface to eat for the first time. Maria Sepulveda, who is an Assistant professor of Forestry and Natural Resources, used electron microscopy to detect nanosilver particles measuring 30 nanometers or less inside minnow embryos. Due to their size, the particles are able to enter egg membranes and enter the eggs themselves in a very short time.Results revealed symptoms of edema and hemorrhaging in the head area.
Nanosilver seems to be more toxic when it is suspended as opposed to when it settles, causing malformations in minnows that are in turn creating alarm among certain environmental and consumer advocate groups. The additional fear is that if nanosilver leaks into the water supply it will kill good bacteria, causing havoc in the environment.
According to Ron Turco, Professor of Agronomy, though silver may be used effectively as an antimicrobial compound, it also may be toxic to microorganisms. In this regard, he claims that its "indiscriminate inclusion into products to allow them to say they are antimicrobial is creating a cautionary issue."
Nanosilver is being considered by EPA for environmental exposure profiling, whereby it could be labeled a pesticide. Right now there are few regulations related to the substance, but testing is in progress, mostly funded by large pharmaceutical companies such as Merck.
On the other side of the playing field are those medical practitioners and scientists who insist that silver nanoparticles change once they are released into the environment. They claim that nanoparticles by nature will affix to salts, minerals, and other substances, forming larger particles that become inert. One argument on this side is the fact that fresh water streams contain billions of minute grains of silver coming from natural silver deposits in their beds or from mining runoff, and that these streams teem with vibrant aquatic life. With over 2 million tons of silver trace minerals in the ocean, there also seems to be no harm being done to its underwater population as a result of silver content.
A report recently released by the UK Royal Commission on Environmental Pollution claims that not enough is known about nano-engineered compounds to justify their wide use. Those who believe in the healthful and non-toxic properties of nanosilver respond that such organizations, including the EPA, may be defending a trillion dollar pharmaceutical industry that has a lot to lose if nano or colloidal silver begins to become popular for its activity in destroying a broad spectrum of viral bugs, including HIV, which has been highlighted in various studies to date. By targeting nanosilver as an environmental pollutant, the industry stands a chance of denying its approval as a viable medication. Because silver cannot be patented, except in specific situations, this also makes it less likely to be approved.
In an article in the Journal of Nanotechnology, a study conducted by the University of Texas and Mexico University was the first to explore the benefits of silver nanoparticles. Calling them pesticides makes one wonder then, why bleach, aerosol disinfectants, antibiotics, and antivirals are not categorized in the same manner.
The jury is not out yet on nanosilver, but there is plenty of evidence on the efficacy of colloidal silver on health while large pharmaceutical companies continue to fund ongoing research as pertains to its effect on the environment. Stay tuned….
