Learn About Bronchiolitis Obliterans (Popcorn Lung)

Key Facts: Bronchiolitis obliterans is a rare chronic lung disease that worsens over time. This disease was first discovered in workers at a microwave popcorn plant who had inhaled the flavoring chemical diacetyl. That is how bronchiolitis obliterans became known as ‘popcorn lung’. Exposure to other chemicals, some lung infections, autoimmune diseases and complications from lung transplants can also cause bronchiolitis obliterans. It is important to note that the similarly named bronchiolitis obliterans organizing pneumonia (BOOP), now referred to as Cryptogenic Organizing Pneumonia (COP), is a completely different disease. How it Affects Your Body The very small airways of the lungs are called bronchioles. Bronchioles can become injured as a result of inhaling a harmful substance, due to an infection, from an autoimmune response or as a complication to a lung transplant. Most of the time, the injury heals normally. Occasionally the body’s repair process becomes overactive, causing the build-up of scar tissue. The thick scar tissue blocks the bronchioles and prevents air from passing through to the alveoli, also called air sacs. This makes it harder for the body to absorb oxygen. The scarring and narrowing of the bronchioles may continue to worsen over time. If left untreated, it could result in irreversible lung damage and respiratory failure. What Causes Bronchiolitis Obliterans Bronchiolitis obliterans is most commonly caused by breathing in toxicants over time. Diacetyl is a frequent cause of exposure that and can be found in artificial butter flavoring and odor products such as popcorn, cake mixes and candy. It also is found in tobacco smoke, flavored tobacco products and vaping products. Some other toxicants linked to causing bronchiolitis obliterans are: Acetaldehyde, found in cannabis and e-cigarette smoke Formaldehyde, a highly irritating chemical used in adhesives and building materials and emitted from e-cigarette smoke Metal oxide fumes, a byproduct of welding Sulfur dioxide, released by burning fossil fuels Ammonia Chlorine Nitrogen oxides Hydrochloric acid Mustard gas, or sulfur mustard