I remember being surprised when I read, several years ago, that cigarettes were once thought to promote health. (I was, if anything, more surprised when I read that there actually are some possible health benefits from smoking. For most people, the risks far outweigh the benefits, however.)
I was even more surprised, reading this evening about the 144th birthday of Marie Curie (recognized by today’s Google Doodle), to find out that radiation was once considered beneficial. Can you imagine wanting to brush your teeth with radioactive toothpaste?
There are times that the benefits outweigh the risks. A few months after giving birth in 1992, I was tested for low thyroid levels. The test required use of some kind of radioactive dye, and I had to stop nursing my son for a week. Rather than pump and throw out milk for a week, I decided to just wean him a month earlier than I had planned (he was about five months old). It presumably had little if any effect on my health or his, and it enabled the doctor to prescribe the medication I needed (and have been taking ever since).
Most of the time, though, radiation kills. That’s precisely its purpose when used on cancer patients – to kill the cancer cells. (And it’s an unavoidable effect that a lot of healthy cells get killed too.) It’s hard to imagine now, in a day when anyone working with radioactive materials in a lab has to wear a radiation monitoring badge, that people once thought it was a good idea to line a ceramic drinking cup with uranium. (It’s even harder for me to imagine how they thought that would reduce flatulence.)