An Army private gets x-rayed in this Korean War-era image. (Otis Archives)
Radiation may have its funny side. Offbeat superheroes use x-ray vision to see ladies naked. Off-balance individuals sport tinfoil hats to protect their brains from mind-control rays.
But too much radiation is deadly serious. With CT scans on an upswing in recent years, people are concerned about safe imaging and the possible effects of too much radiation.
“Don’t have too many x-rays” has always been the common wisdom. I cringe whenever one of my kids needs a hurt limb x-rayed or the dental hygienist puts a heavy lead apron on me and then hides behind a barrier.
With modern diagnostics, things have gotten more complicated. We’re urged to have regularly scheduled mammograms, dental x-rays and diagnostic screenings. We may get a CT scan for an unexplained ache or pain. Ironically, taking careful care of our health on a regular basis means we may be exposed to more radiation.
A variety of sources produce that emission of energy in high-speed particles or waves that we call radiation. From an hour on a sunny hilltop to nuclear fallout, we can be exposed to it in many ways. We receive radiation in some form when flying in an airplane, driving near a cell tower or nuclear power plant, or receiving cancer treatment in the form of radiation therapy. Some scientists think that a wee bit of “normal” exposure is even beneficial, like a little oil or a little wine. This school of thought is called hormesis.
The typical American gets exposed to 200 millirems a year of radiation just from walking around. We get it not just from that diagnostic testing but from cosmic rays from the sky, from radiation emanating from the ground or from housing materials, and even a small amount from radioactive material we ingest. This is considered a normal level of exposure.
There are two types of radiation, ionizing and non-ionizing. The ionizing variety, of which environmental radiation and medical radiation are two types, is high-frequency, with the power to zap molecules and atoms and affect the DNA of cells. The non-ionizing kind, low-frequency and weaker, is found in power lines, computer and TV screens, radio waves, cell phones, microwaves, most electrical devices and visible light. Most of this kind is not thought to cause cancer, although ongoing research is investigating to what extent non-ionizing radiation affects cells.