• The concentration of asbestos fibres in the air
  
• How long the exposure lasted
  
• How often you were exposed
  
• The size of the asbestos fibres inhaled
  
• The amount of time since the initial exposure
  

When inhaled in significant quantities, asbestos fibres can cause asbestosis (A scarring of the lungs which makes breathing difficult), mesotheliomia (A rare cancer of the lining of the chest or abdominal cavity), and lung cancer.  The link between asbestos and othe types of cancers is less clear.
Based on current information there is no evidence that vermiculite currently available for horticultural purposed (eg potting plants) is a health risk when used as directed.

Minimizing Your Risks
The best way to minimize your risk to asbestos exposure is to avoid disturbing asbestos containing materials in any way.  If asbestos is contained and not exposed to the home or interior environment, it poses very little risk.

If you are concerned that your home may contain asbestos visit the Health Canada Wed site to get the most up-to-date information as it becomes available.

If you know you have asbestos in your home take precautionary steps. 


Vermiculite Insulation Containing Asbestos
Some vermiculite insulation may contain asbestos fibres.  These products can cause health risks if disturbed during maintenance, renovation or demolition.  However, there is currently no evidence of risk to your health if the insulation is sealed behind wallboards of floorboards, isolated in an attic or otherwise kept from exposure to the interior environment.

Background
Vermiculite is a mica-like mineral mined around the world and used in a variety of commercial and consumer products because it is fire-resistant and has good insulation qualities.  Of concern is vermiculite ore produced by the Libby Mine in Montana from the 1920s to 1990.  It was sold as Zonolite Attic Insulation and possibly other brands in Canada during that time.  Vermiculite from the Libby Mine supplied the majority of the world market in vermiculite based insulation.

Products made form vermiculite ore produced by the Libby Mine were not widely used after the mid 1980s and have not been on the market in Canada for more than 10 years.  Not all vermiculite produced before 1990 contains asbestos fibres.  However, to be safe and the absence of evidence to the contrary, it is reasonable to assume that if your building has older vermiculite-based insulation, it may contain some asbestos.

The Health Risks of Vermiculite Containing Asbestos
Although the overall percentages of asbestos in bulk vermiculite are very low, the airborne percentages can increase if the material is disturbed.  Asbestos poses health risks only when fibres are present in the air that people breathe.  If asbestos fibres are enclosed or tightly bound in a product, for example in asbestos siding or asbestos floor tiles, there are no significant health risks.  How exposure to asbestos can affect you depends on:

• The concentration of asbestos fibres in the air
  
• How long the exposure lasted
  
• How often you were exposed
  
• The size of the asbestos fibres inhaled
  
• The amount of time since the initial exposure
  

When inhaled in significant quantities, asbestos fibres can cause asbestosis (A scarring of the lungs which makes breathing difficult), mesotheliomia (A rare cancer of the lining of
the chest or abdominal cavity), and lung cancer.  The link between asbestos and other types of cancers is less clear.
Based on current information there is no evidence that vermiculite currently available for horticultural purposed (eg potting plants) is a health risk when used as directed.

Minimizing Your Risks
The best way to minimize your risk to asbestos exposure is to avoid disturbing vermiculite-based insulation in any way.  If vermiculite-based insulation is contained and not exposed to the home or interior environment, it posed very little risk.

If you are concerned that your home may contain vermiculite-based insulation visit the Health Canada Wed site to get the most up-to-date information as it becomes available.

If you know you have vermiculite-based insulation in your attic take these precautionary steps;

1. Do not allow children to play in an attic with open areas of vermiculite-based insulation and make sure anyone working in the attic knows about the possible presence of asbestos.
2. Do not use the attic for storage if retrieving items form it may disturb the insulation.
3. If you must go into the attic walk on boards in order to minimise disturbance of the insulation and use an appropriate respirator mask.  Do not remain in the attic longer than necessary.
4. Common dust masks are not effective against asbestos fibres.
5. If you decide to remove vermiculite-based insulation, speak to trained and qualified abatement personnel.

Need More Info?
Visit the following sites.

Health Canada’s information on the Home Insulation Web site at
www.hc-sc.gc.ca/english/insulation/index.html

The Canada Mortgage and Housing Corporation publication  About Your House, Asbestos at :
www.cmhc-schl.gc.ca/en/burema/gesein/abhose/abhose/abhose_ce03.cfm


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