Fiber years
The term "fiber years" is used to estimate tumor risk. One fiber year = 1 x 10 to the power of 6 fibers / m³ x 1 year.
The risk of lung cancer, for example, doubles after 25 fiber years, whereas mesothelioma can occur without evidence of minimal asbestosis and even after a low level of exposure (Herold 2022).
The latency period between exposure and the onset of lung cancer ranges from a minimum of 15-19 years (Kasper 2015) to a maximum of 60 years (Matthys 2009). The higher the exposure was, the greater the risk of disease (Kasper 2015).
Health hazards
As early as the turn of the 19th / 20th century, health problems caused by inhaling asbestos were recognized. But it was not until 1972 that the WHO's International Agency on Cancer confirmed a direct link between the inhalation of asbestos dust and the incidence of cancer (Dyllick 2013).
In Germany, a regulation on hazardous working materials was issued in 1972, and in 1973 the employers' liability insurance associations issued a regulation on "protection against mineral dust hazardous to health" (Büttner 2004).
Asbestosis, for example, has been part of the Occupational Diseases Ordinance since 1929 (Baur 2005).
Mesothelioma ofthe pleura and peritoneum resulting from asbestos exposure was added to the Occupational Diseases Ordinance (BKV) in 1977 (Büttner 2004).
In 1987, the International Agency for Research on Cancer (IARC) classified asbestos as a Class I carcinogen (Huang 2021).
In 1992, lung cancer was recognized after 25 fiber years of asbestos exposure.
Laryngeal carcinoma was added to the BK- list with amendment in 1997, and ovarian cancer in 2017 (Kraus 2020).
Nowadays, in developed countries, asbestos has been largely replaced by synthetic mineral fibers such as glass fibers, refractory ceramic fibers. However, it is still used in developing countries (Kasper 2015).
Prophylaxis
In Germany, both the manufacture and use of asbestos have been banned since the Hazardous Substances Ordinance of 1993 came into force - with the exception of its use as diaphragms for chlorine potassium electrolysis (Büttner 2004), EU-wide only since 2005 (Herold 2022).
As of 2019, asbestos is banned in 66 countries or regions of the world (Huang 2021).
Secondary prevention is for unavoidable exposure. As materials containing asbestos are still present in many buildings nowadays, demolition, renovation and maintenance of asbestos are now legally regulated by the Official Journal of the European Union, EU Directive 2009/148/EC on the protection of workers at work from asbestos. The Official Journal contains detailed information on dust control measures, wearing of special protective work suits, use of fine dust filters and regular occupational medical examinations (Büttner 2004).