Asbestos is a previously common building material that is now recognised as harmful to human health. During the late 20th century, scientists and doctors established that asbestos is a dangerous and toxic substance that should not be in any home. For years, asbestos had been used for fireproofing and strengthening construction materials used in building houses. However, later medical studies reveal that asbestos can damage the lungs and is a potential carcinogen. In an instant, knowledge of the harmful effects of asbestos spread like wildfire, and before you know it, the construction material was banned in many countries.