Popcorn Lung Symptoms and Causes

  • Medical Author:
    George Schiffman, MD, FCCP

    Dr. Schiffman received his B.S. degree with High Honors in biology from Hobart College in 1976. He then moved to Chicago where he studied biochemistry at the University of Illinois, Chicago Circle. He attended Rush Medical College where he received his M.D. degree in 1982 and was elected to the Alpha Omega Alpha Medical Honor Society. He completed his Internal Medicine internship and residency at the University of California, Irvine.

  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

In 2004, The US Centers for Disease Control and Prevention (CDC) reported several cases of bronchiolitis obliterans in workers in a microwave popcorn plant in Missouri in 2000. Bronchiolitis obliterans is a serious and irreversible condition in which the tiny air sacs in the lungs become scarred. After investigation by the NIOSH (National Institute of Occupation Safety and Health), it was discovered that a flavoring agent, diacetyl, was used to give the popcorn a buttery taste, and that inhalation of this flavoring likely contributed to the development of the illness. The disease that results often is associated with cough and shortness of breath, similar to that seen in people with chronic obstructive pulmonary disease (COPD). This process is irreversible by current therapy.

More recently, a legal case was settled in Colorado for over $7 million dollars. The award was granted to a consumer who developed bronchiolitis obliterans ("popcorn lung") after eating two bags of microwaved popcorn every day for 10 years. Since workers who manufacture microwaved popcorn were at risk, the judgment stated that the popcorn manufacturers and the supermarket corporations should have realized that consumers could be at risk of this lung disease too.

Do e-cigarettes cause popcorn lung?

It is not only microwave popcorn that contains dangerous chemical flavorings such as diacetyl. A study published in 2015 in the journal Environmental Health Perspectives showed that harmful chemicals associated with "popcorn lung" are present in many types of flavored e-cigarettes, particularly those with flavors like fruit and candy that may appeal to young smokers. Of the 51 flavored e-cigarettes tested, flavoring chemicals were found in 47 and diacetyl specifically in 39 samples. This suggests a potentially dangerous level of exposure via e-cigarettes to chemicals that can cause severe lung damage.

What are the symptoms of popcorn lung?

As mentioned previously, the symptoms of "popcorn lung" are primarily cough and shortness of breath. These symptoms can develop slowly and subtly, gradually progressing to more disabling symptoms over time. Some people with the condition have

Severe exposure as seen in microwave popcorn plant workers may include inflammation of the skin and mucosal surfaces (eyes, nose, and/or throat). In general, however, because the symptoms are so similar to tobacco-related COPD as well as asthma, the diagnosis may be difficult to make without a high level of suspicion.

How is popcorn lung diagnosed?

The diagnosis of popcorn lung begins by taking a thorough history, and additional testing is required to confirm the diagnosis. Lung function testing, chest X-rays, and CT scans are essential. To confirm the diagnosis of bronchiolitis obliterans, biopsy is necessary, often requiring an open lung surgical procedure. The disease can be randomly located in lung tissue, making it difficult at times for the pathologist to make an accurate diagnosis.

What is the treatment for popcorn lung?

The primary treatment of popcorn lung is removal of any exposure to the diacetyl agent. For workers, this requires special facial coverings as well as a respirator mask. In some cases, they must be removed from the work environment. For consumers, avoidance of exposure is essential. In some people this will result in a gradual abatement of symptoms if the process was diagnosed early enough. In others, however, the disease can progress and may even require lung transplantation.

Popcorn Lung Symptoms and Causes Resources

Doctor written main article on Bronchiolitis

Medically reviewed by James E. Gerace, MD; American Board of Internal Medicine with subspecialty in Pulmonary Disease


Allen et al. Flavoring Chemicals in E-Cigarettes: Diacetyl, 2,3-Pentanedione, and Acetoin in a Sample of 51 Products, Including Fruit-, Candy-, and Cocktail-Flavored E-Cigarettes. Environ Health Perspect DOI:10.1289/ehp.1510185

Centers for Disease Control and Prevention. "FLAVORINGS-RELATED LUNG DISEASE." Updated Sep 29, 2015.

National Institutes of Health. "DIACETYL: Human Health Effects."

ABC News. "Colorado man Wayne Watson wins $7 million in "popcorn lung" lawsuit.

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Reviewed on 4/13/2016

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