Okay - this will sound dumb but inquiring minds need to know. I have, for work, been researching the toxicity of urnaium. During this research I found a reference to Fiesta dinner ware and its uranium content. I bought a set of Fiesta at a tag sale and use it everyday. I love it. On the back of the pieces there is "lead free" stamp. Can I asume since there is no lead there is no uranium in my dishes and the refernece I found was for dishes produced prior to mine?