Asbestos Roofing

Asbestos (asbesto cement) was very popular roofing and siding material in the past. Mainly due to its fireproofness and the fact that you could have got asbestos shingles or panels of any shape, type or dimension, it was used quite often both in business and residential buildings.

Fibre cement roofing meant asbestos roofing

Yes, there were the times when the so called fiber cement roofing meant actually the asbestos roofing.

In fact, asbestos is not just one mineral - there are six very similar commercially used minerals called asbestos. These are as follows:
- chrysotile (or white asbestos belonging among serpentines);
- crocidolite (or blue asbestos belonging - together with all the next asbestos forms - among amphiboles);
- amosite;
- tremolite;
- anthophyllite;
- tremolite and
- actinolite.

What all the above minerals have common is that they form fine fiber particles, which - if loosen in the air - are polluting both the indoor and outdoor air.

Asbestos exposure risks

Asbestos (all forms) is the natural material, existing in the terrestrial crust where it is extracted in the open-pit mines. There are several places on Earth where the asbestos is mined, e.g. Brasil, Russia, Zimbabwe, South Africa, Kazakhstan, but also Canada (asbestos gave name to the place on the Skootamatta River in eastern Ontario).

Asbestos is only dangerous when its loose fibres are inhaled. The long term asbestos exposure (over 20 years of regular inhalation IN MINING, PROCESSING or DEMOLITION of asbestos) can cause the asbestosis, which is sort of pollution of the lungs with specific chronic symptoms like inflammation of the lung tissue that leads in the excessive deposition of collagen (also called fibrosis) at various thoracic sites and also lung cancer and malignant pleura and peritoneum tumors (mesothelioma).

The number of building and construction professionals with diseases caused by long or intensive asbestos exposure is high, therefore usage of asbestos is forbidden in many countries. Nevertheless, the most of above professional were affected by malicious effects of asbestos because they were continuously exposed to the huge volume of loose asbestos fibers.

There is slightly different situation in the standard life (if you are not employed in the asbestos processing, of course) where the risk is quite low.

To compare the lethality risks of long-term asbestos exposure (if the asbestos material is painted and absolutely without any damages like cracks that could help loosen the dangerous fibres) check the following chart (by B. Mossman and P. Slovic)

Natural risk         Lethal ratio
smoking         21%
road accidents         1.7%
household accidents         0.84%
deadly falls         0.56%
drawnings         0.21%
air crashes         0.01%
1 diet soda daily         0.007%
tornados         0.0005%
14years of school attendance (school has quality,
painted exterior asbestos siding)         0.00001%.

So please, do not panic.