Background

Scientific American in 2008 published an article entitled: Do Nanoparticles in Food Pose a Health Risk? The article reports the widespread use of nanoparticles (NPs) in food or food-related products that do not bear the warning that they may pose a health risk. The FDA does not require NPs to be proved safe, but rather requires the foods having NPs to not be harmful. In 2006, the EPA began to regulate nanosilver as a pesticide and as a result companies using nanosilver as an antimicrobial agent are required to register them as pesticides. Friends of the Earth, an environmental group, insist that reporting of nanosilver use by companies should be mandatory, given the potential risks and has suggested the definition of what constitutes a health risk to include NPs < 300 nm in diameter. But Andrew Maynard of the Woodrow Wilson International Center for Scholars notes it is the effect rather than the size that is significant. See http://www.scientificamerican.com/article.cfm?id=do-nanoparticles-in-food-pose-health-risk

Toxicity by Surface Area and Size

Currently, the mechanism by which NPs pose a health risk is not well understood. NP size controls the surface area and therefore the effectiveness of colloidal silver. NPs are thought to be more reactive than larger particles of the same substance, because they have more surface area and therefore have more opportunity to interact with other substances in their surroundings, i.e., a material that is otherwise harmless at the macroscale is likely to be toxic if it is processed to the nanoscale as NPs. See http://www.scientificamerican.com/article.cfm?id=will-nano-particles-present-big-health-problems The problem with quantifying toxicity by NP surface area and size is that both lack a mechanism to produce EM energy of at least 5 eV to form the reactive oxidative species (ROS) necessary to act as bactericidal agents. EM stands for electromagnetic. Similarly, the significance of “effect rather the size” in toxicity suggested by the Wilson Center lacks a mechanism to produce the ROS.

QED Induced EM Radiation Toxicity

More recently, the toxicity mechanism of NPs capable of producing ROS was proposed to find origin in quantum mechanics. Toxicity is found to almost be independent of the material, although silver has received the most attention because of its use as a bactericide in baby food. By this theory, atoms in NPs lack specific heat because at ambient temperature the heat capacity in submicron NPs resides at wavelengths < 1 micron that may only be populated at temperatures greater than about 6000 K. At ambient temperature, the heat capacity is therefore “frozen out”, and so NPs lack the heat capacity to conserve absorbed EM energy from colliding water molecules in body fluids by an increase in temperature. Conservation may only proceed by the QED induced frequency up-conversion of absorbed EM energy to the EM resonance of the NP. QED stands for quantum electrodynamics. Typically, ionizing QED radiation is emitted at UV or higher levels thereby producing the ROS that damage DNA from which cancer may develop. NPs < 100 nm are required to produce ROS through ionizing radiation. In contrast, NPs > 100 nm emit non-ionizing QED radiation in the VIS and IR. See http://www.nanoqed.org at “DNA damage by NPs”, 2010.

Colloidal Silver

Colloidal silver comprising silver NPs in solution is related to the controversy over the risks of silver NPs in food products. Colloidal silver has been used for fighting infections for thousands of years. But for the last 40 years, silver colloids have been proven to be cancer-causing agents. Indeed, silver is listed in the 1979 Registry of Toxic Effects as causing cancer in animals. Silver finds antibiotic action from the fact that it is a non-selective toxic biocide. See e.g., http://www.cqs.com/silver.htm  Regardless, fine silver NPs provide greater effectiveness than coarse NPs because toxicity is predicated on exposing the infected region to the largest possible surface area. See http://www.silver-colloids.com/Reports/reports.html#CompTable

 Safe Colloidal Silver?

Currently, comments to the Scientific American article stated if the widely touted “natural antibiotic” usage of colloidal silver is a potentially dangerous thing, then: Are there any safe colloidal silvers? Or Are the silver components in such preparations larger than problematic?  

Answers to these questions depend on effectiveness. Colloidal silver is perfectly safe if not taken at all, but is not effective if other antibiotic agents are not used. Least effective are silver colloids with coarse NPs > 100 nm because the QED radiation emitted by the NPs in the VIS and IR is non-ionizing. Most effective are fine NPs < 100 nm, but come at the risk of damaging the DNA by UV or higher ionizing radiation that can lead to cancer.

 Moreover, coarse NPs accompanied by fine NPs actually enhance the DNA damage above that by fine NPs alone. Hence, manufacturers would have to guarantee that all NPs in the colloidal silver are > 100 nm to avoid ionizing radiation. Manufacturers of colloidal silver would be required to label the minimum size of NPs in their products to allow the customer himself to weigh the risk of DNA damage to antibiotic effectiveness.  

 Conclusions

1. NPs by emitting QED induced ionizing radiation are significant antibiotic agents, but pose a health risk by collateral damage to DNA the consequence of which may lead to cancer. DNA damage must always be considered in the use of NPs as antibiotics.

2. All NP materials produce about the same QED radiation because their refractive indices are similar. Therefore, only the NP size distinguishes whether ionizing or non-ionizing is emitted. Labeling of the minimum size of NPs in a product allows the customer to weigh the respective advantages and disadvantages.

3. Colloidal silver with NPs < 100 nm produce ionizing QED radiation at UV or higher levels that damage the DNA and can lead to cancer even though being used for thousands of years.

4. Safe colloidal silver may be found at minimum effectiveness. If manufacturer control all NPs > 100 nm, non-ionizing QED radiation is then emitted.  Controlling NPs > 300 nm can only err on the safe side.

5. The safest way of avoiding future cancers caused by DNA damage is to ban all NPs < 300 nm from food products, especially baby food.