A ‘Scream' 

Editor:

While Tom Abate didn't actually quote Dr. Richard Stepp about the risks of radiation from the Japanese nuke plant disaster, the comparison of radiation from a nuclear power plant to a medical X-ray, in any dose, is highly misleading ("The FUD Factor," March 17). No one ever needs to be decontaminated after an X-ray. Radiation from X-ray scanners at the airport doesn't stick to your clothes, skin or hair. You can't inhale X-rays. You won't become internally contaminated if you eat food or drink water that has been X-rayed.

There's an important difference between ionizing radiation and non-ionizing radiation. Nuclear power plants use and produce ionizing radiation. That is, the radioactive materials that emit neutrons which ionize atoms that they come in contact with. X-rays, like radio waves and visible light, are radiation of a particular frequency, but do not involve neutrons at all, and are therefore called non-ionizing radiation.

Nuke plants use highly unstable isotopes of heavy metals as fuel. The atoms of these materials contain more neutrons than they can hold on to for long. Eventually, these extra neutrons break away from the atom and fly off into space. When the neutron breaks away from the atom, the atom emits a burst of high-frequency energy - a "scream," if you will. This "scream" can be in the X-ray or gamma ray frequency range. In the nuke plant, when the neutron flies into space, it eventually hits another unstable atom and this collision causes the atom to split in two, releasing two neutrons and more "screams." Those neutrons hit other atoms, which split, "scream" and emit more neutrons. In the nuke plant, the neutrons drive the nuclear chain reaction, and the "screams" generate the heat that drives the turbines.

Both the neutrons and the "screams" can be harmful. The "screams" can cause radiation burns and acute radiation sickness in very high doses. But at much lower doses, this aspect of radiation is not considered very harmful - no more harmful than a medical X-ray, in fact.

The neutrons are another story. Externally, your skin will protect you from most neutrons associated with ionizing radiation. However, if you breath in just the tiniest particle of plutonium, which all of those reactors contain, it will continue to bombard the delicate tissue in your lung with neutrons for the rest of your life, with the very likely result that you will develop lung cancer in that spot. Once ingested in food or water, radioactive metals tend to accumulate in the kidneys, where neutron bombardment causes cancer, and the materials form kidney stones. Radioactive iodine, apparently released in large doses from Fukushima, attacks the thyroid, causing cancer. Strontium, an isotope of calcium, attacks the bones in the same way. Depending on the half-life of the radioactive materials involved, the material can remain highly radioactive for a few months or up to tens of thousands of years.

A medical X-ray, on the other hand, is just the "scream" - no neutrons, no ions, no dust, no radioactive isotopes and no half-life. It's essentially a radio, tuned to a particular frequency, and when they turn it off it stops transmitting. A medical X-ray machine is a powerful transmitter, certainly, and nothing to fool around with, but a medical X-ray is nothing like the Pandora's box of poisons that live inside a nuclear reactor. ...

While panic-stricken behavior will likely cause more harm than good, a dismissive attitude based on misleading reassurances doesn't help either. In fact, that's what got us into this mess to begin with.

John Hardin, Redway

Editor's note: This week Dr. Richard Stepp elaborates on his radiation comments in this week's guest opinion.