So, what is all the concern really about – will these radiation scanners increase your risk of cancer or other diseases? A group of scientists and professors from the University of California at San Francisco voiced their concern to Obama’s science and technology adviser John Holdren in a well-stated letter back in April.
The group included experts in radiation biology, biophysics, and imaging, who expressed serious concerns about the dangerously high dose of radiation to the skin.
Radiation increases cancer risk by damaging the DNA and various components within the cells. Much of the damage is caused by high concentrations of free radicals generated by the radiation. Most scientists think that the most damaging radiation types are those that have high penetration, such as gamma-rays, but in fact, some of the most damaging radiation barely penetrates the skin.
One of the main concerns is that most of the energy from the airport scanners is concentrated on the surface of the skin and a few millimeters into the skin. Some very radiation-sensitive tissues are close to the skin – such as the testes, eyes, and circulating blood cells in the skin.
This is why defenders using such analogies as the dose being 1,000-times less than a chest X-ray and far less than what passengers are exposed to in-flight are deceptive. Radiation damage depends on the volume of tissue exposed. Chest X-rays and gamma-radiation from outer space is diffused over the entire body so that the dose to the skin is extremely small. Of note, outer space radiation does increase cancer rates in passengers, pilots, and flight attendants.