Occasionally the dangers of radiation pop up in the media and extreme claims on either side surface.
Some months back, I read an article that quoted a concern about the presence of radioactive particles in dust near current and former Department of Energy facilities. There was concern that inhaling two such particles would result in an individual receiving their lifetime allowable dose. This appraisal was incorrect and adds to a sometimes irrational fear of radiation.
As a health physicist, or radiation protection specialist, at DOE-contracted Sandia National Laboratories, I take measurements and process calculations to determine the dose of radiation people get from radioactive material ingested or inhaled. This is usually referred to as internal dosimetry. I am also an adjunct professor at the University of New Mexico, where I teach students about this topic.
After examining the data presented in the article, I found that the dose imparted by the radioactive particles in dust would have been about a quarter the dose one might get from eating a banana.
The problem with improperly presenting the risk of radiation is twofold: Overstatements needlessly frighten people or, conversely, entice them to ignore a real risk when it exists because they do not believe they see evidence for it. Also – and this does happen – people refuse important medical tests because of misinformation that improperly balances the risks and benefits of radiation.
Certainly, large doses of radiation are dangerous, but we shouldn’t overlook the good because of unfounded fears. Benefits of the use of radiation and radioactive materials are well-known. These include cancer and other treatments, medical diagnostic procedures, sterilization of medical instruments and blood, industrial processes that determine the quality of pipe welds, and many more. If the radiation and radioactive materials are properly used and cared for, it’s a minimal risk to the public but a large benefit.
Airborne radioactive particles are always around us in the form of radon gas, which electrostatically can attach to dust particles. Exposure to radon is considered a “background” radiation dose, or a dose one gets just from living on Earth.
There are three factors that affect the hazard posed by inhaled radioactive particles: radiation type, particle size and specific activity. It’s important to know the relative damage each type could cause, whether the particle can be inhaled into the lung, and how much radiation there is within the particle.
As people living in the U.S. are continually confronted with all types of risk, both man-made and in the environment, it is very important that we are provided the information to help us judge these risks. There are risks using electricity and household chemicals, fire and cars. Most people still use all these things because they have been taught how to avoid injury.
There is little evidence that radiation presents a risk at low doses as opined by the Health Physics Society, a national organization devoted to radiation protection. This includes doses incurred during air travel, living at higher altitudes, eating Brazil nuts or potato chips, and other regular exposures.
The National Academies of Science reports that a dose of 0.01 “sieverts,” approximately the dose received from two chest X-rays or three times the natural background, may increase the chance of cancer by 0.0008 percent, or 80 cancers per 100,000 adult males. The rate of cancer for 100,000 adult males, however, is 45,000, whether or not they were exposed to radiation.
The point is not that 80 cancers are unimportant, but we statistically cannot be sure any of those cancers are caused by low doses of radiation from particles of dust or other unrelated activities.
Severe radiation injuries occur to very few. In fact, actual attributable cancers to radiation exposure are rare.
The correct information allows us to make the right decisions for us and our families.
Charles Potter is a health physicist at Sandia National Laboratories in Albuquerque and an adjunct professor at the University of New Mexico in the nuclear engineering program.