Asbestosis is a form of pulmonary fibrosis caused by contact with asbestos (asbestos exposure). Pulmonary fibrosis usually worsens progressively. Asbestosis is therefore classified as a malignant dust lung disease (so-called pneumoconiosis).
In most cases, certain occupational groups are affected. Asbestosis is therefore one of the recognized notifiable occupational diseases. It is the second most common occupational disease in Germany after noise-induced hearing loss.
In addition to asbestosis, asbestos causes other diseases, including malignant tumors in the
On average, 30 years pass between exposure to asbestos and the manifestation of asbestos-related diseases. For this reason, a significant increase in asbestos-related diseases is not expected in Germany until 2020, following the ban on asbestos in 1993.
The first symptoms appear as the lung tissue changes. The usually progressive pulmonary fibrosis is accompanied by
accompanied by chest pain. A crackling sound can often be heard above the lungs.
Initially, shortness of breath occurs mainly during exertion and deep inspiration (exertional dyspnoea). As it progresses, it also occurs during periods of rest (dyspnoea at rest).
The lung tissue, which has been transformed into connective tissue, can no longer adequately supply the body with oxygen.
The lack of oxygen supply (hypoxemia) is indicated by
- thickening fingernails (so-called drumstick fingers) and a blue
- a blue coloration of the skin, mucous membrane, lips and finger ends (so-called cyanosis)
visible. In addition, the blood now flows more slowly through the lungs as a result of the hardening of the tissue, so that it can back up to the heart.
This disrupts heart function to such an extent that heart failure - known as cor pulmonale - develops. Cor pulmonale manifests itself in the form of shortness of breath and fluid accumulation (edema) in the ankles and lower legs. In some cases, life-threatening cardiac arrhythmias can also be observed.
Asbestosis is caused by inhaled asbestos-containing dust. The asbestos fibers settle in thealveoli (air sacs) of the lung tissue. They then enter the connective tissue of the lungs, where they break down into very fine fibers. Later on, they also migrate into the pleura.
Wafer-thin asbestos fibers become lodged in the lungs and lead to scarring © Wirestock Exclusives | AdobeStock
The asbestos fibers are extremely durable. The body cannot break them down or excrete them. However, the scavenger cells of the immune system (macrophages) absorb the inhaled asbestos fibers and try to break them down. Instead, they release messenger substances that activate the so-called fibroblasts (the main component of connective tissue). More connective tissue cells are formed, making the tissue thicker and less flexible.
The messenger substances also attract other immune cells, which cause tiny inflammatory foci in the lung tissue. This tissue damage in turn causes an increased release of fibroblasts, which further promotes tissue scarring.
Due to the increasing inflexibility of the tissue, the gas exchange surface of the lungs shrinks(reduced lung volume). The scarred tissue means that less oxygen can reach the blood, making it harder to breathe in, especially under stress.
Most of those affected come into contact with asbestos at their workplace. Before the ban on asbestos in 1993, there were no adequate protective measures in place, quite the opposite: protective work clothing itself sometimes contained asbestos.
The following product types generally contained asbestos until the ban:
- Preformed insulation material for the thermal insulation of pipes and boilers
- Fire protection made of sprayed asbestos in pipes, (ceiling) panels, fire barriers, partition walls or around steel structures
- Acid and heat-resistant seals made from a rubber-asbestos mixture
- insulating boards used for fire protection or thermal insulation, for partitions or pipes
- Fire barriers in ceiling cavities
- Paper, paper products or felt materials for the insulation of electrical appliances or as a fireproof top layer on wood fiber boards (asbestos paper)
- Asbestos textiles such as twine, yarns, cords, ropes, hoses, packings, cloths or clothing
- Cement products in flat and corrugated sheet metal for roof and wall cladding, guttering, rainwater pipes and water tanks
- Textured coatings such as Artex
- Roof cladding made from bitumen
- Floor tiles made from thermoplastic or vinyl
- Paints, sealants, plastic resin mats, etc.
- Fire-resistant protective work clothing
- Friction linings such as clutch or brake linings
- talcum (powder form of talc or soapstone)
However, exposure to asbestos does not necessarily lead to the development of a lung disease. It is not yet clear why some people fall ill and others do not, despite proven long-term exposure to asbestos.
What is certain, however, is that if other risk factors are added, the probability of disease increases, especially the risk of tumor development. For example, the risk of a malignant lung tumor is ten to forty times higher in smokers with a history of asbestos exposure.
In addition to soldiers, workers in manual occupations also have an increased risk:
- Tradesmen working with metal plates or construction workers (including in the shipbuilding sector),
- Vehicle builders (including rail vehicle builders),
- (gas) fitters,
- carpenters,
- electricians,
- builders and construction workers,
- plasterers,
- steelworkers and sheet metal workers,
- painters and
- welders.
Despite the ban on asbestos, some occupational groups still come into contact with asbestos today. As asbestos is still used in older buildings, asbestos exposure can occur during demolition and renovation work, for example.
Safe protective clothing must be worn when handling asbestos © Bernard MAURIN | AdobeStock
The lung tissue is irreversibly damaged and cannot be cured, at least not with current treatment concepts. The primary treatment goal is therefore
- to slow down the fibrosis of the lung tissue and
- alleviating the symptoms through additional symptomatic therapy.
The first priority here is to avoid asbestos dust. In the case of smokers, smoking cessation is added to prevent further deterioration.
No pharmacological treatment approaches are yet available for asbestosis. Corticosteroids and immunosuppressants have not proven effective in either monotherapy or combination therapy. However, bronchodilator drugs (so-called brochial dilators) can significantly improve the subjective sensation.
Supportive pulmonary rehabilitation with
- aerobic conditioning,
- mobility and strength training,
- training in breathing and relaxation techniques,
- nutritional counseling and
- psychosocial support
are carried out. As the disease progresses, patients usually require oxygen therapy. If cancer is diagnosed as a complication, the tumor is usually removed surgically and then treated with chemotherapy or radiotherapy.