OMG, my grandmother told me that yesterday and I didn't really believe her. I mean, I thought anything's possible, but I'll have to check that out. She said my aunt used to go garage sale searching for Fiestaware because she had a bunch of it and loved collecting it, but then found out the red dishes were slightly radioactive and got rid of it all (this was a long long time ago, like early 80s when she did that).
How crazy! Good to know that's not a problem any more.
My rule of thumb is still to check the bottom for either 'lead free' or a date after 1974. The really old stuff can be so pretty, but it's not a chance I'm willing to take. I've had great luck with my Fiestaware. I've only broken one cup and 2 salad plates in the last 10 years. They're pretty chunky and hold up very well even if they get crashed around a bit. I don't think I even have any chips in them and we use them every day.