The controversy over asbestos arose because certain kinds of asbestos have been shown to cause serious health problems, such as cancer, but it's an inexpensive and effective insulator already installed in countless buildings. Studies of the health threats posed by sprayed versus pre-formed asbestos in recent decades have controversial outcomes. Some people conclude that this product should be outlawed while others insist it can be installed and maintained with minimum hazard. People still have misconceptions after the highly publicized controversy, yet much of their concern is warranted.
In the 1970s, asbestos became the primary insulation across the globe because it was fire retardant and insulated against both temperature and sound. A decade had to pass before the damage those who mined it and installed it became evident as people fell ill to respiratory illnesses, like asbestosis, and began dying of the lung cancer called mesothelioma. Soon, widespread health studies spurred by lawsuits narrowed the cause of death and found that only friable, or spray-on, asbestos of certain varieties were causing cancer. In the early 1990s, the Health Effects Institute and the Environmental Protection Agency published reports that fibers from this material must be airborne before they enter the respiratory system. Therefore, the elimination of friable asbestos would all but eliminate related conditions.
Manufacturers denied that the controversial use of asbestos was so dangerous as to require that it be phased out and eliminated from construction. They began to use chrysotile asbestos to form insulation tiles in a factory and be transported to the construction site. With this change, the worst cancer risk was reduced to possibly affecting miners and factory workers, but was not dangerous to the general population occupying business or residential buildings. Plans were eventually made to phase out other similar products in the 1990s, backed by less robust scientific evidence, to ease people's distrust.
As far as the friable and chrysotile asbestos that was already installed, a controversy arose over whether the insulation in old buildings might disintegrate and re-release dangerous dust that could be inhaled and cause cancer. Again, some people believed that it was more destructive to disturb the tile by demolition of buildings, since this breaks apart the fibers. Others, including many European experts, wanted to eliminate all instances of friable asbestos through costly demolition. A consensus in the controversy in America was reached by instituting strict maintenance schedules of asbestos-insulated buildings, instead of demolition. Experts also considered the danger of lives lost to fire by using less effective insulation, which was estimated as a larger number than the lives threatened by asbestos.