Secondhand Smoke and Allergies
Study demonstrates that allergies and secondhand smoke don’t mix
Researchers at the University of California recently conducted a new study to determine the effects that secondhand smoke may have on an individual with allergies. Nineteen nonsmokers with a ragweed allergy participated in this study.
The study was fairly straightforward. Each participant first had their nasal passages rinsed, which is referred to as ‘lavage.’ The fluid from the rinsing process was collected for testing. After the initial lavage was complete, each person was then exposed to either clean air or secondhand smoke in a sealed chamber for 2 hours. Another lavage was conducted.
The second stage of the experiment involved exposing each participant to either ragweed or a placebo. Once the allergen was introduced, lavages were conducted much more frequently and for a longer follow-up period. The lavage fluid was analyzed for IgE, a key antibody which is related to allergic response, as well as histamine, which is one cause of allergic inflammation.
Astoundingly, even after four days those participants who were exposed to the combination of ragweed and secondhand smoke had levels of IgE that were 16.6 times higher than participants who had been exposed to the combination of ragweed and clean air! For those exposed to the allergens and smoke, nasal histamine also remained elevated after four days.
This study provides the first clear evidence that secondhand smoke can potentially worsen allergic reactivity. Obviously, if you have allergies, it’s in your best interest to avoid exposure to smokers.
June 14, 2006
American Academy of Allergy, Asthma & Immunology