Although asbestos is a natural mineral, exposure to this substance is not safe for humans. Asbestos can lead to the development of serious or fatal illnesses such as the aggressive type of cancer known as mesothelioma. The International Agency for Research on Cancer (IARC) classifies all forms of asbestos as group 1 carcinogens.
You can learn more about mesothelioma from an organization that employs one of my former students.
A useful spread sheet of all known and probable carcinogens can be downloaded in various formats( including Excel )directly from IARC.