What is Thorium?
Thorium is a naturally occurring, radioactive substance. In the environment, thorium exists in combination with other minerals, such as silica. Small amounts of thorium are present in all rocks, soil, water, plants, and animals. Soil contains an average of about 6 parts of thorium per million parts of soil (6ppm). More than 99% of natural thorium exists in the form of thorium-232. It breaks down into two parts-a small part called “alpha” radiation and a large part called the decay product. The decay product is also not stable and continues to break down through a series of decay products until a stable product is formed. During these decay processes, radioactive substances are produced. These include radium and radon. These substances give off radiation, including alpha and beta particles, and gamma radiation. Some rocks in underground mines contain thorium in a more concentrated form. After these rocks are mined, thorium is usually concentrated and changed into thorium dioxide or othe
Thorium (symbol Th, atomic number 90) is a radioactive chemical element. Thorium is a silvery-white metal at room temperature, but will readily oxidize when exposed to air, and only occurs naturally in oxidized form. Although thorium is not fissile, it can be bred in a nuclear reactor to the fissile isotope U-233, and so has potential as a nuclear fuel source. Thorium is also used as an alloying element with other metals, and is the primary ingredient in gas lantern mantles. Thorium naturally occurs in the Earth’s crust, at a concentration of around twelve ppm (roughly the same as lead, and three times that of uranium). Although thorium is radioactive, its fourteen billion-year half-life is so long that most of the Earth’s original thorium is still there. The primary ore for thorium is the mineral monazite, which can have up to 10% thorium content by mass; a few other minerals, such as thorianite and euxenite, also contain significant amounts of thorium. Although many countries have la
Thorium is a naturally-occurring, slightly radioactive metal discovered in 1828 by the Swedish chemict Jons Jacob Berzelius, who named it after Thor, the Norse god of war.It is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium.Soil commonly contains an average of around 6 parts per million of thorium. Thorium, as well as uranium, can be used as a nuclear fuel. Although not fissile itself, thorium-232 will absorb slow neutrons to produce uranium-233, which is fissile. Hence like uranium-238 it is fertile. Domestic Production and use: The primary source of the world s thorium is the rare-earth and thorium phosphate mineral, monazite.Monazite was not recovered as a salable product during domestic processing of heavy mineral sands in 2001. Past production had been as a byproduct during processing for titanium and zirconium minerals, and monazite wasrecovered for its rare-earth content. Essentially all thorium compounds and alloys consu
Thorium is a naturally-occurring, slightly radioactive metal discovered in 1828 by the Swedish chemict Jons Jacob Berzelius, who named it after Thor, the Norse god of war.It is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium.Soil commonly contains an average of around 6 parts per million of thorium. Thorium, as well as uranium, can be used as a nuclear fuel. Although not fissile itself, thorium-232 will absorb slow neutrons to produce uranium-233, which is fissile. Hence like uranium-238 it is fertile. Domestic Production and use: The primary source of the world’s thorium is the rare-earth and thorium phosphate mineral, monazite.Monazite was not recovered as a salable product during domestic processing of heavy mineral sands in 2001. Past production had been as a byproduct during processing for titanium and zirconium minerals, and monazite wasrecovered for its rare-earth content. Essentially all thorium compounds and alloys consu
This Public Health Statement is the summary chapter from the Toxicological Profile for thorium. It is one in a series of Public Health Statements about hazardous substances and their health effects. A shorter version, the ToxFAQs™, is also available. This information is important because this substance may harm you. The effects of exposure to any hazardous substance depend on the dose, the duration, how you are exposed, personal traits and habits, and whether other chemicals are present. For more information, call the ATSDR Information Center at 1-888-422-8737.
