- With Mayo Clinic asthma and allergy specialist
James T C Li, M.D., Ph.D.read biographyclose window
James T C Li, M.D., Ph.D.James Li, M.D.
"People with allergy or asthma can lead full and healthy lives." — Dr. James Li
Dr. James Li is chair of the Division of Allergic Diseases in the Department of Internal Medicine and a board-certified asthma and allergy specialist. He hopes his expertise and the information on the site educates health care consumers in an area of rapid change both in medications and diagnoses.
"There are a lot of misperceptions about allergy and asthma," says Dr. Li, a New York City native who has been with Mayo since 1985 and works with a group of subspecialists in allergy, asthma and immunology. "I believe it's important to provide truthful, accurate information about allergy and asthma to the public. The more people know, the better they can take care of these conditions."
Dr. Li is a professor of medicine at College of Medicine, Mayo Clinic. He's a past director of the American Academy of Allergy, Asthma & Immunology, the American Board of Allergy and Immunology, and the American Board of Internal Medicine. He's a fellow in the American College of Allergy, Asthma & Immunology.
The American College of Allergy, Asthma & Immunology honored him with the Distinguished Service Award, and the American Academy of Allergy, Asthma & Immunology with its Special Recognition Award.
Tests and diagnosis (1)
- Reactive airway disease: Is it asthma?
- Asthma and acid reflux: Are they linked?
Treatments and drugs (2)
- LABAs for asthma — Should I stop taking them?
- Albuterol side effects: What's normal?
Lifestyle and home remedies (3)
- Ozone air purifiers: Can they improve asthma symptoms?
- Asthma: Why are symptoms worse during my period?
- Asthma diet: Does what you eat make a difference?
- Hygiene hypothesis: Early germ exposure prevents asthma?
Ozone air purifiers: Can they improve asthma symptoms?
My daughter has asthma. Would she benefit from an ozone air purifier in her room?
from James T C Li, M.D., Ph.D.
Despite manufacturers' claims, ozone air purifiers don't remove asthma triggers from the air. In fact, inhaled ozone can make asthma worse.
Ozone generators sold as air purifiers intentionally produce the gas ozone. Ozone can mask odors by changing the chemical composition of particles or other gasses in the air, making the air seem fresher and cleaner. However, ozone generators don't actually filter out the small particles that trigger asthma.
Inhaling ozone, even in small amounts, can irritate the lungs. Specific effects may include throat irritation, coughing, chest pain and shortness of breath, as well as an increased risk of respiratory infections.
Some ozone air purifiers are made with an ion generator or "ionizer" in the same unit. You can also buy ionizers as separate units. Ionizers do remove particles from the air, causing them to attach to nearby surfaces or to each other and settle out of the air — but they may generate unwanted ozone.
Air filters that remove small particles — such as high-efficiency particulate air (HEPA) filters — are effective in removing allergens from the air, without posing any ozone concerns. To work effectively, filters need to be cleaned or replaced regularly, according to the manufacturer's instructions.Next question
Asthma: Why are symptoms worse during my period?
- Ozone generators that are sold as air cleaners. U.S. Environmental Protection Agency. http://www.epa.gov/iaq/pubs/ozonegen.html. Accessed July 10, 2013.
- Auten RL, et al. Biochemical effects of ozone on asthma during postnatal development. Biochimica et Biophysica Acta. 2011;1810:1114.
- Kim KH, et al. A review on human health perspective of air pollution with respect to allergies and asthma. Environment International. 2013;59:41.