|Asbestos Overview and Handling Recommendations (GTZ, 1996)|
|Part II. Asbestos|
|3. Environmental aspects and health hazards due to Asbestos|
The hazard of Asbestos is due to the size and shape of the fibers. The prerequisite for damage to humans is the occurance of Asbestos particulates which can enter the lungs. Such fibers have aerodynamic diameters at or below 7 micrometers, whereby the aerodynamic diameter is about 3 times larger than the actual diameter (IACS). The resulting health damaging effect has been recorded since the beginning of this century. ln 1927, the term "Asbestosis" was assigned to the symptoms of a lung disease, and referred to the chronic lung disease with a change in the lung tissue due to the fibrogenic effect of Asbestos. Asbestosis ends frequently with lung cancer, in which case Asbestos is the promoter or co-carcinogenic agent.
In 1955, the significant link between Asbestos exposure and lung cancer was first confirmed scientifically. Another Asbestos-caused form of cancer, the mesothelioma of the pleura and peritoneum, has been researched since 1960.
In the Federal Republic of Germany the described diseases were recognized as occupational sicknesses (1936: Asbestosis; 1943: Asbestosis in combination with lung cancer, 1970: mesothelioma of pleura and peritoneum).
Asbestosis has been known of and observed the longest. Its occurance is linked to the exposure of high fiber concentrations; the exposure period is extends from years to decades. The average latent time of Asbestos-caused lung cancer is considered to be 25 years. However, it must be considered that different factors can influence the outbreak of the disease. For instance, the danger of acquiring Asbestosis increases by a factor of 53, if in addition to Asbestos exposure the risk factor of smoking is present, since the main human protection mechanisms, e.g. the mucuciliar transport of fibers by the cilia, are not functional or at least strongly impaired. (IACS)