Asbestosis: Specialists and Information

The first symptoms appear as the lung tissue changes. The usually progressive pulmonary fibrosis is accompanied by

• a slowly progressive dry cough,
• shortness of breath,
• shortness of breath (dyspnea), and
• chest pain

. A crackling sound is often heard over the lungs.

Initially, shortness of breath occurs mainly during exertion and deep inhalation (exertional dyspnea). As the condition progresses, it also occurs at rest (resting dyspnea).

The lung tissue, which has been replaced by connective tissue, can no longer adequately supply the body with oxygen.

The lack of oxygen (hypoxemia) is indicated by

• thickening of the fingernails (so-called clubbing) and
• a bluish discoloration of the skin, mucous membranes, lips, and fingertips (known as cyanosis)

. In addition, as a result of the tissue hardening, blood now flows more slowly through the lungs, causing it to back up toward the heart.

This disrupts heart function to such an extent that heart failure—known as cor pulmonale—develops. Cor pulmonale manifests as shortness of breath and fluid retention (edema) in the ankles and lower legs. In some cases, life-threatening cardiac arrhythmias may also occur.

Asbestosis is caused by inhaling dust containing asbestos. The asbestos fibers settle in the alveoli of the lung tissue. From there, they enter the connective tissue of the lungs, where they break down into very fine fibers. As the disease progresses, these fibers also migrate into the pleura.

Hair-thin asbestos fibers become lodged in the lungs and lead to scarring © Wirestock Exclusives | AdobeStock

Asbestos fibers are extremely durable. The body cannot break them down or excrete them. However, the immune system’s scavenger cells (macrophages) take up the inhaled asbestos fibers and attempt to break them down. Instead, they release signaling molecules that trigger the activation of so-called fibroblasts (the main component of connective tissue). An increased number of connective tissue cells form, causing the tissue to thicken and become less flexible.

The signaling molecules also attract additional immune cells, which cause tiny foci of inflammation in the lung tissue. This tissue damage, in turn, triggers an increased release of fibroblasts, further promoting tissue scarring.

Due to the tissue’s increasing stiffness, the gas exchange surface area of the lungs shrinks (reduced lung volume). The scarred tissue allows less oxygen to enter the bloodstream, making it harder to breathe, especially during physical exertion.

Most people affected come into contact with asbestos at their workplace. Before the asbestos ban in 1993, there were no adequate protective measures; on the contrary, some protective work clothing even contained asbestos itself.

The following types of products generally contained asbestos until the ban:

• Preformed insulation material for thermal insulation of pipes and boilers
• Fire protection made of sprayed asbestos in ducts, (ceiling) panels, fire barriers, partition walls, or around steel structures
• Acid- and heat-resistant gaskets made from a rubber-asbestos mixture
• Insulation boards used for fire protection or thermal insulation, for partitions or ductwork
• Fire barriers in ceiling cavities
• Paper, paper products, or felt materials used to insulate electrical equipment or as a fire-resistant covering on wood fiber boards (asbestos paper)
• Asbestos textiles such as twine, yarn, cord, rope, hoses, gaskets, cloth, or clothing
• Cement products in flat and corrugated sheet metal for roof and wall cladding, gutters, downspouts, and water tanks
• Textured coatings such as Artex
• Bitumen roofing
• Floor tiles made of thermoplastic or vinyl
• Paints, sealants, plastic resin pressed mats, and similar materials
• Fire-resistant workwear
• Friction linings such as clutch or brake linings
• Talc (powdered form of talc or soapstone)

However, exposure to asbestos does not necessarily lead to the development of lung disease. It remains unclear why some people develop the disease while others do not, despite proven long-term exposure to asbestos.

What is certain, however, is that when additional risk factors are present, the likelihood of developing a disease increases, particularly the risk of tumor formation. For example, the risk of a malignant lung tumor is ten to forty times higher among smokers with a history of asbestos exposure.

In addition to soldiers, people in manual trades are also at increased risk:

• craftsmen and construction workers who work with metal sheets (including those in the shipbuilding sector),
• vehicle builders (including rail vehicle builders),
• (gas) installers,
• carpenters,
• electricians,
• construction workers and tradespeople,
• plasterers,
• steel fabricators and sheet metal workers,
• painters, and
• welders.

Despite the ban on asbestos, some occupational groups still come into contact with asbestos today. Since asbestos is still present in older buildings, exposure to asbestos can occur, for example, during demolition and renovation work.

When handling asbestos, safe protective clothing must be worn © Bernard MAURIN | AdobeStock

The lung tissue is irreversibly damaged and cannot be cured—at least not with current treatment approaches. The primary goal of treatment is therefore

• to slow the progression of fibrosis in the lung tissue and
• to alleviating symptoms through additional symptomatic therapy.

The top priority here is avoiding exposure to asbestos dust. For smokers, quitting smoking is also essential to prevent further deterioration.

To date, no pharmacological treatment options are available for asbestosis. Corticosteroids and immunosuppressants have not proven effective, either as monotherapy or in combination therapy. However, bronchodilators can significantly improve the patient’s subjective symptoms.

Pulmonary rehabilitation with

• aerobic conditioning,
• flexibility and strength training,
• training in breathing and relaxation techniques,
• nutritional counseling, and
• psychosocial support

are provided. As the disease progresses, patients usually require oxygen therapy. If cancer is diagnosed as a complication, the tumor is generally removed surgically and then treated with chemotherapy or radiation therapy.