erionite

Erionite is a naturally occurring fibrous mineral that belongs to a group of minerals called zeolites. It usually is found in volcanic ash that has been altered by weathering and ground water. Erionite forms brittle, wool-like fibrous masses in the hollows of rock formations and has an internal molecular structure similar to chabazite.

Some properties of erionite are similar to the properties of asbestos; however, erionite is NOT currently regulated by the U.S. Environmental Protection Agency as one of the six asbestos fibers.

Erionite was first described by A.S. Eakle in 1898, as white woolly fibrous masses in cavities in rhyolite lava near Durkee, Oregon. It was originally thought to be another relatively rare zeolite named offretite, which is very similar to erionite in appearance and chemical composition.

Tumorigenesis

Erionite is a type of mineral fiber similar to but much more potent than crocidolite in causing MM. For example, about 20% of mice injected with high doses of crocidolite developed malignant mesothelioma (MM), compared with 100% of mice injected with erionite.

Erionite has been linked to a MM epidemic in Cappadocia, Turkey, and there is a general agreement that it is the most dangerous and potent carcinogen in causing human MM.

There is a wrong perception that erionite exist only in Cappadocia; in fact, deposits of erionite are present worldwide, although the contribution of erionite to the epidemic of MM in the US and in the Western world in general has not been investigated.

A research team has compared the chemical and crystal structure of the erionite from Cappadocia to the erionite found in other parts of the world, and we have found no differences that could be linked to a postulated higher level of carcinogenicity of the Cappadocian erionite. These results underscore the potential risk of erionite exposure in the Western world.