RELEASE OF URANIUM AND EMISSION OF RADIATION FROM URANIUM-GLAZED DINNERWARE

Samples of orange, yellow, beige, ivory and blue-green ceramic dinnerw are glazed with uranium compounds have been examined. Measurements at glaze surfaces yielded exposure rates of 3.8-16 mR/h (1-4 mu C/kgh) fo r orange glazes and rates of 0.04-1.3 mR/h (0.01-0.3 mu C/kgh) for ivo ry, beige, and yellow glazes. Whole body exposure from a shelf display of 40 orange dishes was estimated to be 0.1-0.5 mR/h (0.03-0.13 mu C/ kgh), or up to 50 times the room background radiation level, at a dist ance of 1 meter. Twenty-four hour leaching tests of orange, yellow, an d ivory dishes were carried out with various concentrations of acetic and citric acids. Uranium concentrations in leachates of some orange d ishes exceeded 450 mg/l. Uranium is a chemical nephrotoxin and the Uni ted States Environmental Protection Agency has proposed a maximum cont aminant level for drinking water of 0.020 mg/l. Eased on this value a person consuming 2.21 of drinking water per day would ingest 0.31 mg o f uranium per week. A person eating once a week from an orange glazed dish could easily ingest IO or more times this amount.