Understanding Radiation

Ionizing Radiation

Ionizing radiation is radiation that changes the structure of individual atoms by ionizing them. The ions produced in turn ionize more atoms. Substances that produce ionizing radiation are called radioactive.

Radioactivity is a natural phenomenon. Nuclear reactions take place continuously on the sun and all other stars. The emitted radiation travels through space, and a small fraction reaches the earth. Natural sources of ionizing radiation also exist in the ground. The most common of these are uranium and its decay products.

Ionizing radiation is categorized into four types:

X-rays are usually man made radiation produced by bombarding a metallic target with electrons at a high speed in a vacuum. Xrays are electromagnetic radiation of the same nature as light waves and radio waves, but at extremely short wavelength, less than 0.1 billionth of a centimeter. They are also called photons. The energy of x-rays is millions of times greater than that of light and radio waves. Because of this high energy level, x-rays penetrate a variety of materials, including body tissue.

Gamma rays occur in nature and are almost identical to x-rays, but generally have a shorter wavelength than x-rays. Gamma rays are very penetrating.

Beta radiation. A beta particle consists of an electron emitted from an atom. Beta particles penetrate matter less deeply than gamma or x-rays, but they are biologically significant because they can be more effective than gamma radiation at disrupting cellular material.

Alpha radiation. An alpha particle consists of two protons and two neutrons, the same as the nucleus of a helium atom. It generally can travel no more than 1 to 3 inches in air before stopping, and can be stopped by a piece of paper.

When an atom emits an alpha or beta particle or a gamma ray, it becomes a different type of atom. Radioactive substances may go through several stages of decay before they change into a stable, or non-radioactive form.

An element may have several forms, or isotopes. A radioactive form of an element is called a radioisotope or radionuclide. Each radionuclide has a half-life, which is the time required for half of a quantity of the material to decay.

The following chart shows the complete decay chain for uranium 238, which ends with a stable isotope of lead. Notice that the half- life of the radionuclides in the chain range from 164 microseconds to 4.5 billion years.

“Vitamin R” - Radiation Good For Your Health!

In 1980, Professor T.D. Luckey, a biochemist at the University of Missouri, published a study, entitled Hormesis With Ionizing Radiation (CRC Press, Boca Raton, FL; also in Japanese, Soft Science Inc., Tokyo), of over 1200 experiments dating back to the turn of the century reporting the effects of low-level radiation on biota ranging from viruses and bacteria through various plants and animals up to vertebrates. He found that, by all the criteria normally used to judge the well-being of living things, modest increases of radiation above the natural background make life better: they grow bigger and faster; they live longer; they get sick less often and recover sooner; they produce more offspring, more of which survive. The phenomenon of “hormesis”–whereby things that become harmful at high concentration are actually beneficial in small doses–is established in chemical toxicology. The effect is believed to result from stimulation and exercising of the natural immune system. What Luckey showed was that it applies also to radiation.

Some further facts that are consistent with this conclusion:

* Iowa, the state that the EPA found as having the highest average level of radon in the home, also has below-average cancer incidence. The mountain states, with double the radiation background of the US as a whole, show a cancer rate way below Iowa’s. Data from a study of 1729 U.S. counties shows the correlation between radon and lung cancer mortality to be about the same as for cigarette smoking; except that it’s negative: the more radiation, the less cancer.

* The same extends worldwide. The waters of such European spas as Lourdes, Bath, and Bad Gastein, known for their beneficial health effects since Roman times, all have high radioactivity levels. Areas noted for high radiation backgrounds, such as the Caucasus, southwest England, northwest India, have high longevity and low cancer incidence.

* British data on over 10,000 UK Atomic Energy Authority workers show cancer mortality to be 22% below the national average. For Canada the figure is 33%. (Imagine the hysteria if those numbers were the other way around!)

It appears, however, that the political consequences of announcing this to a public that has been saturated with contrary propaganda for over 20 years would be unacceptable. Although papers and conferences on radiation hormesis are now regular features of the scientific scene, they are ignored by the lawmakers and regulatory authorities. The continuing assumption of proportionate damage by tiny doses contradicts everything that has been discovered about cell metabolism and the mechanism of DNA repair since the early sixties.

If a little extra radiation is good for you, what optimum dose should our local health-food store recommend? Work reported from Japan puts it roughly at two “millirems,” per day. That’s about a tenth of a dental X-ray, or one coast-to-coast jet flight, or a year’s worth of standing beside a nuclear plant. For comparison, the level where the net effect becomes harmful is around two rems per day; 50 (note, we’re talking rems now, not millirems) causes chronic radiation sickness; 100 is lethal.

Perhaps tablets for those who don’t get enough regular exposure wouldn’t be a bad idea. A good way to use radioactive waste might be to bury it under radon-deficient homes. And perhaps cereal manufacturers should be required to state on their boxes the percentage of the daily dietary requirement that a portion of their product contributes. After all, if radiation is essential for health in minimum, regular amounts, it meets the accepted definition of a vitamin!

As a further note to put things in perspective, her are some figures comparing radiation exposures experienced by the average American from various sources, natural and man-made.

Annual estimated doses in mREMs per year:

All rocks contain traces of uranium. Radiation from the granite used in Grand Central Station exceeds the NRC limits for nuclear-plant operation. Grand Central Station wouldn’t get a license as a nuclear plant. Neither would the piers of the harbor at Dun Laoghaire, near where I live in Ireland.