What kind of asbestos causes mesothelioma

Asbestos remains unchanged in the lungs for up to 40 years


The ancient Greek word “Asbestos” does not mean “immortal” for nothing: Asbestos fibers remain stable in the lungs for a period of almost 40 years and are therefore verifiable, which in many cases makes the diagnosis easier.

© IG BAU (R + W, Petra Berger)

Asbestos fibers can be detected in the same amount in the human lungs for almost 40 years. This was shown by an evaluation of the German Mesothelioma Register at the Institute for Pathology at the Ruhr University Bochum (RUB) (see European Respiratory Journal, online publication on June 29, 2017). The data set contains measurement results of the asbestos concentration in the lungs of one and the same people, which were obtained every 4 to 21 years.

Asbestos, a fibrous mineral found in natural rock, is valued in industry for its bio-persistence. Hence its name from the ancient Greek word "Asbestos", which stands for "immortal". The lung dust analyzes carried out over 30 years and now, for the first time, longitudinally evaluated data confirm this bio-resistance also for the human lungs. The researchers around Inke Feder and Prof. Dr. Andrea Tannapfel, together with colleagues from the Institute for Prevention and Occupational Medicine (IPA) of the German statutory accident insurance, included twelve cases in their investigation.

"The special thing about our data set is that many years after the end of asbestos contact in one and the same person with an asbestos-related lung disease, the asbestos concentration in the lung tissue was determined several times at intervals of 4 to 21 years," explains Inke Feder. "The asbestos concentration in the lungs remained stable over this long period of almost 40 years and was therefore detectable." This result applies to both blue asbestos, which is considered to be more hazardous to health, and white asbestos. For the latter - the one most commonly used in industry - experts have so far disputed whether the fibers survive in the lungs or not.

While foreign particles that have entered the lungs are usually caught by cilia, then transported back into the airways and coughed up, fine fibers such as asbestos can penetrate deep into the alveoli. As a reaction of the lungs, mesh-like, net-like diffuse scarring with the dusts stored in it can form, the so-called asbestosis. Since the asbestos fiber is so bio-resistant, the scavenger cells of the immune system (alveolar macrophages
Scavenger cells of the immune system, which fulfill a variety of functions in the alveoli, for example cleaning the lungs by absorbing foreign particles (pathogens, dust, soot, etc.). They are, among other things, also involved in inflammatory and hypersensitivity reactions.
) don't dismantle them. These phagocytes die off and form the typical asbestos corpuscles
These are rod-shaped, brownish structures (up to 5 micrometers in length) in the lung tissue with a central dust fiber and bulb-shaped swellings that originate from a protein coat containing hemosiderin (i.e. iron). Since such asbestos bodies are not only specific for asbestos, but can also occur in connection with other fibrous dust crystals, the generic term “ferruginous bodies” has become established. Mineralogical dust analyzes are required for the detection of asbestos.
. This releases ingredients that cause chronic inflammation, which can lead to cancer. In addition, elements accumulate in this shell structure, which can also be responsible for the carcinogenic effect of the asbestos bodies.

A typical asbestos-related tumor is mesothelioma mesothelioma
Benign or malignant tumor that originates from the unicellular layer of cells on the surface of certain organs (squamous epithelium of the serous membranes), for example the pleura, the peritoneum or the pericardium.
which affects the pleura, among other things. Lung cancer, larynx cancer and ovarian cancer can also be caused by asbestos. That is why asbestos has not been allowed to be used in Germany since 1993 and in the European Union since 2005.

The time between the first contact with asbestos and the onset of an asbestos-related disease can be 10 to 60 years. "This means that an asbestos-induced illness can still break out, although the last asbestos contact was a long time ago," explains Andrea Tannapfel, Director of RUB Pathology. Because treatment options vary widely, it is essential to separate asbestos-related diseases from others. Lung fibrosis that is not caused by asbestos, for example, can be treated with drugs that are not approved for asbestosis, as no efficacy has been shown to date.

Lung transplantation in the case of advanced fibrosis is generally not an option for asbestosis patients. "In the X-ray image, lung fibrosis that are not caused by asbestos can hardly be distinguished from asbestosis," explains Prof. Dr. Rolf Merget, occupational physician at the IPA. "It is therefore of central importance that asbestos fibers are still detectable in the lung tissue after such a long time."

Last but not least, the question of the detectability of asbestos fibers in the lungs is crucial for how to assess the risk from asbestos in the workplace. This leads to the decision as to whether a lung disease can be recognized as an occupational disease, so that those affected are entitled to compensation.

Source: Ruhr University Bochum