Interstitial lung disease is not one but a variety of conditions. The lung contains tiny air sacs called alveoli that expand and contract during breathing and help oxygenate the body and remove carbon dioxide. Interstitial lung disease causes the tissue surrounding these alveoli to harden and become scarred, thereby reducing expansion and contraction and making it harder to breathe. The condition may occur slowly over time or rapidly, and once the scarring in the lung has occurred, the process is irreversible.
Microbes
Several classes of microbes may cause interstitial lung disease. Cytomegalovirus is common in patients that have a weakened immune system, according to the Mayo Clinic. Bacterial infections can also cause lung disease, including thermophilic bacteria like Thermoactinomyces. These bacteria grow well in the heat of decomposing organic material like compost heaps. Nonthermophilic bacteria like Bacillus subtilus and Bacillus cereus are also causative agents found in water and detergents. Fungi that are common causative agents of lung disease include Histoplasma species, Aspergillus species, Penecillium species and Cladosporium species. These organisms are found in the environment, food and hot tubs. Amoeba have also been known to cause lung disease; these include Acanthamoeba species and Naegleria species, both of which are found in contaminated water.
Environmental Toxins
The most common occupational element that may cause lung disease is asbestos, which may take years to produce any symptoms. Once symptoms appear, the disease has already progressed and cannot be cured. Silicosis is another work-related illness where silica dust accumulates in the lungs and causes breathing problems. Silica is common in sandblasting, mining and tunneling jobs. A third occupational cause of lung disease is coal worker’s pneumoconiosis, which entails inhalation of coal dust over long periods. The result is scarring of lung tissue over time. Chemicals that may cause harm to the lungs include ammonia and chlorine gas. Ammonia is an irritant and affects the mucous membranes lining the lungs. Chlorine gas is toxic and causes severe lung irritation when inhaled.
Radiation and Drugs
Radiation treatment has been linked to lung damage in cancer patients. When radiation is administered, it tends to destroy healthy tissue along with the cancerous tissue, resulting in damage to the lungs, especially in lung cancer cases. Radiation damage depends on the length and time of exposure. Drugs are also a factor in lung disease. According to the U.S. National Library of Medicine, pharmaceutical drugs like antibiotics, chemotherapy agents, cardiac drugs, anti-inflammatories and autoimmune treatment drugs all have an effect on the lungs either directly or indirectly. Illegal drugs like heroin may also affect the lungs when taken in high doses. The drug has been known to suppress breathing.
