Radiation vs. Radioactive Materials

For many people, just hearing the word radiation can induce an anxiety attack. Since the nuclear disaster began unfolding in Japan over a year ago, most people have heard the term hundreds of times. Do you know what that scary word really means?

From the media reporting of the disaster, it is obvious that few people—including some professional writers—actually do. Radiation simply means energy emitted from a source and absorbed by a target, such as a person. A common light bulb is a source of radiation, emitting both infrared and visible light.

Many in the media routinely confuse the source with the energy. Radioactive materials (source) are what is leaking from the reactors into the environment, not radiation. Radiation (energy) is then emitted from the decaying isotopes (source) wherever the material settles. The actual radiation emitted by the radioactive materials inside the reactors and spent fuel rod storage does not travel far. It acts just like the light from a light bulb; it dims as you get farther from it.

In a similar way, radio signals become weaker with increasing distance from the station. This principle is called the inverse square law. In addition, molecules in the air absorb gamma and other forms of radiation, further weakening it with increasing distance. Lead is a well known absorber of gamma and x-ray radiation. A few inches of lead has the stopping power of hundreds of feet of air.

Radiation is always coming in from outer space, our nearby Sun being the primary source. Other sources are supernova, the monster black holes at the center of our galaxy, quasars and other astronomical sources. The earth’s atmosphere absorbs most of it, protecting people on the ground. Astronauts, frequent fliers and air crews at high altitude are routinely exposed to space radiation. The effects are cumulative.

The energy of radiation can be located anywhere on the frequency spectrum. Follow this link, http://www.weather.nps.navy.mil/~psguest/EMEO_online/module2/module_2_5.html to see a picture of the spectrum of energy. Radiation acts like both waves and particles we know as photons. Visible light is near the middle of the frequency spectrum and exhibits both particle and wave characteristics. Radiation below visible light acts more wave like. Above visible light, it is more particle like. Some forms of radiation are actually beneficial to the target (Rife machines come to mind), some have no harmful effect (visible light) while other types of radiation are clearly lethal.

Radiation below visible light is called non- ionizing. Radiation above ultra-violet is known as ionizing. X-rays and gamma rays are ionizing. The amount of energy packed into each X or Gamma photon is high. When a high energy photon passes through living tissue, it leaves a tiny trail of molecular destruction, acting like a microscopic bullet traveling at the speed of light. If it hits the nucleus of a cell, the DNA there will be damaged.

This happens to us all the time due to the normal background radiation which has always been there, but is higher now. Gamma ray photons are always zipping around in random directions, through our bodies and everything else. Their source is a wide variety of radioactive elements, some naturally present in the environment; others have been added by the bomb tests—Chernobyl, Fukushima and many other accidental releases of radioactive materials since the nuclear Pandora’s box was opened.

Though there is no such thing as a safe dose of ionizing radiation, our bodies have built-in repair capabilities and can clean up the damage from low level exposure. Gamma radiation exposure, even at low (so called normal) levels, causes many types of cancer as well as genetic mutations that are passed on to future generations. People who have been exposed to high levels of radiation should consider not having children. Historically, without the genetic mutations caused by the earth’s natural background radiation, evolution would have proceeded much more slowly.

People living in cities are routinely exposed to a wide variety of non-ionizing, non-nuclear radiation. Radio and TV stations, cell phone and mobile data (3G-4G) masts emit most of it. In your home or business, your cell phone and Wi-fi are the primary sources. Though these forms of radiation are considered dangerous, they are far less harmful than x-rays and gamma rays.

In the United States, the Federal Communications Commission (FCC) regulates the emissions from most radiation sources. Generally, the higher the frequency and the higher the power level, the more dangerous the radiation is.
Radiation from a standard AM radio station is around 1 MegaHertz (MHz). For an FM radio station, it is around 100 MHz, considerably more dangerous than the AM station. Cell phones are in the 800 to 900 MHz range, far worse than any radio or TV station.

Over the last 20 years, new radio and TV stations have located their transmitter and antenna outside the city, due to changing FCC exposure regulations. Some older stations have voluntarily moved their transmitters and antennas in order to expose fewer people. Cell phone masts are everywhere—many of them are far too close to people. The radiation from the above described non-nuclear sources is lower in frequency than visible light and is a non-ionizing form of radiation.

In addition to Gamma Rays, radioactive materials also emit several types of particles that are not electromagnetic radiation. You won’t find them on the frequency spectrum. They are often mistakenly called radiation. They all travel at speeds slower than light.

Some reports from Japan have indicated the detection of Neutron beams coming out of the remnants of the reactor buildings. Neutrons are fundamental particles that are found inside the nucleus of atoms. Each element has a specific number of neutrons. Stable (non-radioactive) elements have a certain number of them, while radioactive isotopes have one or more extra or fewer neutrons. This makes them unstable, prone to falling apart (fission).

When an atom splits, it usually will emit a gamma ray and a neutron or two. These neutrons will hit other atoms, prompting them to split (think of the break shot in a pool game), producing a chain reaction.

In a typical boiling water nuclear reactor, graphite control rods are used to moderate and thus control the rate of reaction. Since graphite is a good neutron absorber, pushing the graphite rods into the core slows the fission rate. Pulling them out speeds up the reaction rate, increasing the reactor power output. The detection of the neutron beams at Fukushima indicates nuclear reactions are still happening at the plant.

Neutrons are very dangerous. They kill exposed organisms quickly. The Neutron bomb was designed to channel most of its energy into neutrons, instead of explosive force. The massive quantity of neutrons generated will kill all living things within a certain radius of the detonation, while causing little blast damage. Fortunately, Neutron bombs are banned by international treaties.

In addition to Gamma rays and Neutrons, some radioactive materials also emit Alpha and Beta particles. Alpha particles are just a flying Helium nucleus and can be stopped by a sheet of paper. They can cause burns if they hit your skin and disease if inhaled or swallowed. Beta particles are just electrons and can be stopped by aluminum foil. Both Alpha and Beta are often mistakenly called radiation. They travel much slower than the speed of light. Though dangerous, they are not really radiation.

There are many types of instruments made to detect radiation and particles. The Geiger counter is the most used type, readily available if you want to buy one. It is mainly used to detect Gamma and X radiation, though with a special thin-walled tube, can detect Alpha and Beta particles as well. Detecting neutrons is not so easy, requiring expensive detectors.

If you visit this Web site, http://www.radiationnetwork.com/, you will see a map of North America that shows the readings of numerous Geiger counters operated by individuals across the continent. These are high end Geiger counters that are connected to the Internet. The site updates every minute with the latest reading from each instrument.


Ray Larsen is a HAM radio operator who resides in Pagosa Springs, Colorado.

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