Amphibole Asbestos Exposure :

Mining activities — Exposure to tremolite asbestos (a type of amphibole asbestos) can occur in workers involved in mining, milling, and handling of other ores and rocks containing tremolite asbestos (such as vermiculite or talc). Residents who live near mining, milling, or manufacturing sites that involve tremolite asbestos-containing material may be exposed to higher levels of airborne asbestos.

Insulation and Building Materials — Amphibole asbestos can be found in a variety of building materials, such as insulation, ceiling or floor tiles, and cement pipes. Amphibole asbestos has been found in some vermiculite sources used as home and building insulation. Much of the asbestos-contaminated vermiculite mined in Libby, Montana, was used to produce attic insulation products.

Workers or homeowners involved in demolition work, maintenance, repair, or remodeling of buildings containing these products can be exposed to higher airborne fibrous amphibole asbestos levels than levels in ambient air. However, exposure can occur only when materials containing asbestos are disturbed in some way to release fibers into the air. When asbestos-containing materials are solidly embedded or contained, exposure risk will be minimal.

Consumer Products — Vermiculite was also commonly sold in gardening and hardware stores. It was used as a soil amendment (conditioner to improve soil quality) or fertilizer carrier, and it was an ingredient in many potting soil mixtures.

In addition, small amounts of amphibole asbestos have been found in some talc-containing crayons. The Consumer Product Safety Commission (CPSC) concluded that the risk is extremely low that children would be exposed to asbestos fibers in crayons. The U.S. manufacturers of these crayons, however, have agreed to eliminate talc from their products.

Regulatory agencies such as the U.S. Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) recognize six asbestos minerals: chrysotile, a serpentine mineral with long and flexible fibers; and five amphibole (with relatively brittle crystalline fibers) minerals, actinolite asbestos, tremolite asbestos, anthophyllite asbestos, crocidolite asbestos, and amosite asbestos.

How Are People Exposed to Amphibole Asbestos?

We are all exposed to low levels of asbestos in the air. These "ambient" - or typical - air concentrations of asbestos fibers are 0.00001 to 0.0001 fibers per milliliter (fiber/mL). Much more concentrated levels of exposure are known to cause health effects in humans.

Asbestos Exposure and Your Work

Asbestos exposure can occur in the workplace, particularly if you work or have worked as a(n):

• Pipe or Steam Fitter

• Plumber

• Brake Repair Mechanic

• Insulation Installer

• Dry Wall Finisher

• Carpenter

• Roofer

• Electrician

• Welder

• Miner

• Shipyard Worker

Individuals who have worked in the above industries should consult with a physician with expertise in the evaluation and management of asbestos-related lung disease.

Chrysotile Asbestos Exposure

The asbestos fibers detected in the samples taken at the World Trade Center sites were chrysotile asbestos.