Classified as a post-transition heavy metal, bismuth has chemical properties that are similar to arsenic or antimony and before modern analysis was possible, bismuth's visual characteristics often meant it was mistaken for lead and tin. Bismuth was one of the first 10 metals to be discovered and so the origin of its discovery is not known but it is thought that its name is derived from Wismuth, possibly from weisse Masse meaning 'white mass'. It was believed that bismuth had the highest mass of a nucleus that didn't spontaneously decay, but this was proven wrong in 2003 when it was found that it is weakly radioactive with a half-life longer than the age of the universe.
Bismuth naturally occurs in the environment, and its oxide and sulphide compounds are commercial ores. When fresh the metal has a silvery-white colour which then oxidises in air to give a rosy hue. Bismuth has a low toxicity for a heavy metal which has meant bismuth alloys have become very popular as replacements for lead, such as in fishing sinkers. It is also an ingredient in some medicines, cosmetics, and pigments.
Compounds of bismuth are less toxic than those of other heavy metals like lead, arsenic, and antimony, which is thought to be due to the low solubility of bismuth salts. Applications of bismuth in medicine are mainly to treat diseases caused by microbial infections and as anticancer agents. It has also been shown recently that radioactive bismuth (synthesised) could be used to kill small volume tumours due to its relatively short half-life and being an alpha particle emitter.
As with other heavy metals, long term exposure may result in side effects and toxicity to humans. A few cases of poisoning can be attributed to occupational exposure in the manufacturing industry, most incidents are due to an overdose of bismuth-containing drugs. Most side effects can be relieved by stopping any ingestion or bismuth therapies.
Typical levels of bismuth in drinking water are of no concern, as a result there are no legal limits set. Bismuth occurs naturally in the environment as well as appearing in industry as a by-product of the smelting of lead and copper, so there are in some cases the potential for bismuth contamination.
Bismuth in your drinking water can be detected by the following tests.
Bismuth can be reduced or removed from your drinking water using the following methods.
