One type of Vermiculite mined in Libby, Montana, was contaminated with tremolite, a type of asbestos. Many workers at the Libby site were found to have abnormally high levels of pleural abnormalities, and a disproportionately high number of those died.
What Types of Asbestos Are There?
There are many different types of asbestos, as well as a multitude of asbestos-like ("asbestiform")products. Many asbestiform materials are not regulated, even though they may cause serious illness or are hazardous.
The main types of absestos are "White Asbestos" (Crysotile), "Brown Asbestos" (Amosite), "Blue Asbestos" (Crocidolite). There are several others that do not fall into any of the three main categories, and these include tremolite, actinolite, and anthophyllite.
What is Vermiculite?
Vermiculite has the chemical formula (MgFe,Al)3(Al,Si)4O10(OH)2·4H2O. It occurs naturally, and is mined in many countries, including South Africa, U.S.A, China and Brazil. It expands when heated, and has uses as a refractory (heat resistant) material, an insulator, but has many other uses due to its high absorbency. These other uses include chemical spill management, and hydroponics (growing plants using water and minerals, and without soil) as it has similar properties to Diatomaceous Earth. Vermiculite is not an asbestos.
Can Vermiculite Cause Mesothelioma and Lung Cancer?
There is no proven link between chemical Vermiculite and any of the serious illnesses with which asbestos is associated. There is, however, one known site at which Vermiculite was contaminated. Vermiculite was mined by W. R. Grace and Co, at Libby, Montana, under the brand name "Zonolite". It was brought to the attention of Government investigators after reports of unusually high levels of death and illness amongst former employees as well as their family members. It was found that the Zonolite contained high levels of tremolite, an asbestiform material. Incredibly, of the residents of Libby who took part in a screening study, about one in six had some level of pleural abnormality.
In 2008 a settlement for $60 million was reached with owners of homes and businesses who used the insulation products that came from Libby. There have been several films and books on the subject of the Zonolite from W. R. Grace & Company. These are listed under "References".
Vermiculite and Asbestosis - Summary
Every asbestos attorney knows that there is no safe level of asbestos or asbestiform material - inhalation of even very small amounts can lead to serious illnesses, including mesothelioma, lung cancer, and asbestosis. This is supported by the fact that the deaths of relatives of those working at the Libby site may have been due to inhalation of tremolite fibres from the environment, or simply from contact with the workers clothes.
Vermiculite References
Documentaries:
Libby, Montana
Dust to Dust
Books:
An Air That Kills , A. Schneider & D. McCumber.
Libby, Montana: Asbestos and the Deadly Silence of an American Corporation , A. Peacock.
Fatal Deception, M. Bowker.
Martin Bell - Martin holds a B.Sc. degree in chemical engineering, and an M.Sc. degree in electronics and computing. He has spent more than 25 years ...
