From the classic column: http://www.straightdope.com/classics/a4_099.html
The question was about whether the old red Fiestaware dishes were radioactive, which they apparently they are, as well as containing some lead. I had some beautiful dishes from Italy that were yellow with blue and green designs. We cooked red chile enchiladas on them all the time, until I tested them and found they contained lead. Probably not a whole lot, but if anything’s gonna leach it into our food, red chile is.
You can get these little tubes to test products, painted furniture, etc. for lead at most hardware stores.