Asbestos is a naturally formed mineral substance, found commonly in construction materials, as it helps to have more heat and chemicals resistance. Due to the potential of intoxicating and provoking diseases like cancer, this is why in some places the substance has been banned to use it for construction purposes.
Regardless of this, there are people that do not want the asbestos found in their properties removed. They have this argument because asbestos become toxic when it is broken and starts to produce dust. Facing the probability of getting intoxicated by it when trying to remove it, some people choose to only remove it if it is already damaged and dusty, because that is when it becomes dangerous for human health.