Ionizing radiation emitted by nanoparticles damages the DNA by penetrating barriers instead of the nanoparticle signaling across the barrier for the DNA to be damaged
Damage by Nanoparticles
On November 4, scientists at the University of Bristol announced that nanoparticles (NPs) of cobalt-chromium damaged DNA on the other side of a cellular barrier. See http://www.bristol.ac.uk/news/2009/6639.html The NPs did not cause the damage by passing through th DNA e barrier which is usually thought. Instead, the Bristol scientists claimed the NPs generated signaling molecules within the barrier cells that were then transmitted to cause damage in cells on the other side of barrier.
However, the NP signaling molecules to induce DNA damage is not likely. Setting aside the fact NPs are inanimate lacking the capability of biological signaling, it is more likely the NPs generate electromagnetic (EM) radiation that readily penetrates the molecular barrier to cause DNA damage. Even if the molecular barrier is replaced with a thin nanometer metal film, the EM radiation can penetrate the film and damage the DNA on the other side.
On October 18-22, at the IEEE Nanomed 2009 Conference in Taiwan, DNA damage was claimed caused by ultraviolet (UV) radiation induced in NPs by quantum electrodynamics (QED). See “DNA damage update” Paper and Presentation at www.nanoqed.org. By this theory, water molecules in body fluids transfer upon collision thermal kT energy at infrared (IR) frequencies to the NPs. However, quantum mechanics (QM) forbids the NPs to have specific heat, and therefore the absorbed kT energy from collisions cannot be conserved by an increase in temperature. Instead, conservation proceeds as the IR radiation is induced by QED to be frequency up-converted to the EM confinement of the NP, typically at UV or even higher frequencies. Subsequently, the UV leaks to the surroundings to cause DNA damage.
NPs provide a significant antibacterial agent in food processing, reducing infections in burn treatment, sunscreen skin lotions, and treating cancer tumors. However, there is a darkside. Over the past decade, experiments have unequivocally shown NPs to induce DNA damage and mimic that by conventional ionizing radiation. See Ibid. What enables the NPs to function to benefit mankind while at the same time posing a health risk is the remarkable fact NPs naturally emit a low level source of continuous UV or higher EM radiation.
The NPs need not be irradiated with lasers, as only collisions with surrounding molecules are sufficient to produce ionizing radiation. The wavelength of the EM radiation is given by 2Dn, where D is the NP diameter, and n is its refractive index. In the Bristol tests, D ~ 30 nm and taking an average n ~ 2.3, the EM radiation had a wavelength of about 140 nm and Planck energy or 8.8 eV.
The DNA damage induced by NPs is a cancer risk if not properly repaired. Given that NPs naturally produce low levels of ionizing radiation beyond the UV from surrounding water molecules, and that natural and man-made NPs are ubiquitous, the conjecture may be made that NPs are the most likely cause of cancers in man. Given the increased risk of NPs producing cancer, the regulation of NPs is highly recommended.