12/05/08 PART 1

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It is that time of year and I love this time of year! Off we went to the local plant nusery to purchase our allotment of vermiculite! I'm getting nervous about the future availability of vermiculite. Every year we hear that it is going to not be sold, because previously it may have contained asbestos, which has been found to be a potential agent that causes a type of cancer. Here is some info...taken from the following website:


Wisconsin Department of Health Services

What are the health risks associated with asbestos exposure?

Asbestos fibers must be inhaled to cause disease.  Disturbing vermiculite insulation or dust containing asbestos will result in exposure unless precautions are taken.  When insulation containing asbestos is disturbed, lightweight asbestos fibers are released into the air and can be inhaled.  In general, the more you are exposed to asbestos, the greater your risk of developing related diseases.  Exposure may not have immediate health consequences, however. In many cases, individuals do not develop related diseases for years or even decades after exposure.

Those at highest risk for exposure and disease are long-term vermiculite processing plant employees or workers regularly installing or handling products containing asbestos without proper protection.  Those at lower risk include people who occasionally disturb attic insulation during activity in the attic or minor "handyman" jobs.  The lowest risk would be for people who live in a home where the vermiculite insulation is isolated and they have had no direct contact with the materials.

Some asbestos-exposed workers, family members, and those living in the neighborhoods of asbestos plants have developed mesothelioma.  Mesothelioma is a rare type of cancer that begins in the tissue surrounding the lungs, stomach, and heart.  Mesothelioma has also been found in individuals who were exposed to asbestos only once decades earlier.  The only known cause of mesothelioma is asbestos.  Exposure to a lot of asbestos over a long time (like in an occupational setting) can cause permanent lung damage known as asbestosis.  Asbestosis causes shortness of breath and increases the risk of serious lung infections.  Smoking also increases the risk of developing illness from asbestos exposure.

What is vermiculite?

Vermiculite is a naturally occurring mineral used in construction, insulation and gardening products.  It looks like shiny, small pieces of popcorn, and is usually light-brown or gold in color.  Vermiculite came from mines in Libby, Montana (closed in 1990) as well as other mines in the U.S. and other countries.  Vermiculite is still mined and distributed for a number of uses, including insulation.

Why should I be concerned about vermiculite insulation?

Much of the Libby vermiculite was used as attic insulation. It was sold under the product name Zonolite.  The Environmental Protection Agency (EPA) estimated in 1985 that 940,000 American homes contained Zonolite attic insulation.

Over 70% of vermiculite ore mined worldwide came from the Libby, Montana mine.  The ore from this mine also included a natural deposit of amphibole/tremolite asbestos.  Much of the vermiculite from Libby was contaminated with asbestos.  Asbestos fibers are invisible to the eye and can only be professionally detected.  Homeowners should consider the following:

  • Vermiculite used for residential insulation may contain asbestos.

  • If you are unsure whether the insulation in your home contains vermiculite, avoid disturbing it until either you or a professional can confirm that it is vermiculite.
  • Vermiculite mined today for use in insulation is from a source considered to be free of asbestos contamination.