Stone sheathing is a way adding decoration to the exterior of a building and has been around since the days of the Romans. Just as furniture can be covered with a veneer of real wood over plywood, buildings can be covered with a veneer of stone. Ideally, stone sheathing is made from synthetic stone that resembles marble, brick, or other types of stone. But for 60 years starting in 1920, stone sheathing was frequently made with asbestos as one of its ingredients.
Portland cement and asbestos were often mixed together to make stone sheathing, as well as other types of siding for buildings. Adding asbestos made the cement resistant to fire, water, and corrosion. But asbestos is also very toxic. Its fibers can be released into the air and once inhaled can cause mesothelioma, a very aggressive form of cancer that affects the lining of the chest or abdomen.
The fact that asbestos is so durable in its practical uses is what makes it so deadly. It is resistant to most chemicals and once it gets into the body, the body cannot break it down or dissolve it. The fibers also get hooked in places like the lining of certain organs and the body has no way of expelling them. They can stay there for decades before the problem is diagnosed. By this time, the mesothelioma is usually in its later stages.