Uranium tile
This article relies largely or entirely on a single source. (March 2018) |
Uranium tiles have been used in the ceramics industry for many centuries, as
The use of uranium in ceramic glazes ceased during World War II when all uranium was diverted to the
Potential doses
Although the uranium in the glaze emits gamma rays, alpha particles, and beta particles, the gamma and alpha emissions are weak. The beta particles are the easiest to detect, and they are also responsible for the bulk of the radiation exposure to those handling ceramics that employ a uranium glaze.
NCRP Report 95 reported the following measurements for dinnerware employing uranium glazes: 0.2 to 20 mrad per hour on contact as measured using film badges;
NUREG/CRCP-0001 reported a measurement of approximately 0.7 mR/hr at 25 cm from a Fiesta red dinner plate. It also reported the results of an Oak Ridge National Laboratory analysis that predicted 34.4 mrem/year to a dishwasher at a restaurant using ceramic plates containing 20% uranium in the glaze, 7.9 mrem/year to the waiters, and 0.2 mrem to a patron for a four-hour exposure.
It is likely that the major health issue associated with this dinnerware is not the radiation exposures but the ingestion of uranium or other heavy metals that have leached into food or drink in contact with the dinnerware. One FDA study[clarification needed] measured 1.66 x 10−5 uCi/ml in a 4% acetic acid solution in contact with the ceramic dinnerware for 50 hours. This exceeded the ICRP's maximum permissible concentration (MPC).
Ordinary ceramics often contain elevated levels of naturally occurring radionuclides, e.g., 40K and the various members of the uranium and thorium decay series. Because of this, health physicists who are conducting radiation surveys expect to see higher readings when they are making measurements over ceramic tiles and similar materials. Sometimes the higher readings are due to uranium in the glaze; sometimes they are due to the radionuclides in the clay that was used to produce the ceramic.
Reported examples include a vehicle carrying toilets setting off a radiation monitor at a truck weigh station, and health physicists at Oak Ridge National Laboratory reporting excessively high readings while surveying newly purchased urinals for the men's restrooms.[2]
Ceramics can be particularly radioactive if some compound of uranium (e.g.,
Background
Not long after
as two new radioactive elements also present with uranium. The relatively highThus, in addition to its medical usage, radium usage also became a major industry in the 1920s and 1930s for making watch, clock and aircraft dials. The
Because it takes approximately three
Taking advantage of this newly abundant resource, the tile and pottery glazing industry then had a relatively inexpensive and abundant source of glazing material that produced a wide variety of colors depending upon admixtures, firing, etc.
Vibrant colors of orange, yellow, red, green, blue, black, mauve, etc. were produced on tiles and other ceramic materials, and by some estimates, some 25% of all houses and apartments constructed during that period (circa 1920–1940) used varying amounts of bathroom or kitchen tiles that had been glazed with varying amounts of uranium. These can now be readily found in older homes, apartments, and other buildings still standing from that era by use of a simple
After
These glazes are generally made with
In most situations, the radiation exposure is not excessive, but there are some exceptions in which pure uranium oxide (which produces red-orange coloration as a glaze) on bathroom floors can pose a hazard for infants crawling around for hours on end, day after day.[citation needed]
See also
References
- ^ Harry McMaster. Earthenware Dishes and Glaze Therefor. Patent No. 1,890,297,[1]
- ^ Frame, Paul (2009-01-20). "General Information About Uranium in Ceramics". demolab.phys.virginia.edu. Retrieved 2022-08-08.
- ^ http://www.nbcnews.com/id/3077213/ns/technology_and_science-science/t/uranium-hunter-follows-trail-tiles/ Uranium hunter follows trail of tiles
- ^ msnbc.com, Alan Boyle (2003-12-12). "Uranium hunter follows trail of tiles". msnbc.com. Retrieved 2019-05-28.
- ^ "Luminescent fairies (Vilnius 2017) – Sencer Sarı".