Question

Radioactivity Question

Radioactive materials used to be used in household goods, such as uranium coated Fiestaware in the 1930's. While eating off a Fiestaware plate could be deadly over a long period of time, keep one plate with the other plates would not cause you significant harm. Why?

Answer 1

Fiestaware plates were produced with nearly 4.5 g of uranium per plate. Thats a lot of uranium taken into our body by eating food off the plate over long periods. In fact the beta dose rates on the human skin were found to be

Distance                       Dose Rate                    Effective Dose Equivalent Rate

            Contact                           24 mrad/hr                            0.0024 mrem/hr

            1 foot                           0.84 mrad/hr                            0.0021  mrem/hr

            3 feet                            0.089 mrad/hr                          4.5 x 10^-4  mrem/hr

The dose rate at contact is nearly 270 times that of at 3 feet. So eating off the fiestaware plate was dangerous over a long period of time while eating off the plates that are kept with fiestaware was not so dangerous. The units are for the measure of radiation.