Controversy About Radiation

Why don’t people, even the experts, agree about the effects of radiation? The short answer to this question is that experts don’t agree because experts can’t scientifically observe if there is an effect on a human due to exposure to radiation at low doses. Why can’t they observe whether there is an effect or not? Because if there is an effect at the doses we are interested in for protecting the public and the worker, it is so small it can’t be conclusively seen in scientific studies. The fact that there is disagreement provides some comfort that the effect can’t be very large or it would be conclusively seen. Experts do agree that radiation can and does cause observable health effects at high doses (doses greater than 500 mSv). It’s when we get down to low doses (doses less than 100 mSv) that we see very different opinions about possible effects. With the lack of conclusive scientific evidence comes the need to develop theories and hypotheses about how low-dose radiation may, or may not, cause an effect. This opens the door for opinion and speculation to enter into the issue with the need to make social decisions about when to control radiation exposure and when it is “safe.”

In the rest of this section, we are going to examine some of the reasons for disagreement. Some are social, some political, and some scientific. The bottom line? Low doses of radiation can be considered safe; that is to say, their risk of causing a harmful effect is small in relation to other risks we take on a daily basis. We can sometimes see changes in human cells when they are exposed to radiation, but what does that mean for us—is it a bad thing, is it a good thing, or does it really matter? There are thousands of daily interactions within our cells that cause damage (not from radiation) and we are okay. It is unlikely that radiation interactions with a cell are any different—the radiation might not damage the cell and we are okay; the radiation might damage the cell and there is a great chance that we are still okay.

Study results for humans exposed to low-level radiation simply are not consistent; however, most show that there is no change in the rates of disease with low-level radiation exposure. Remember, though, that there are studies showing decreases in disease with low-level radiation exposure and some showing increases in that same disease with the same amount of radiation exposure. That inconsistency is why there is controversy.