For millions with allergies, exposure to airborne proteins from cats, dust mites, or mold can trigger symptoms ranging from sneezing and itchy eyes to severe asthma attacks. Unlike germs, these allergens are not alive and can't be "killed," often persisting indoors for months or years. Researchers at the University of Colorado Boulder have now found a potential solution: using safe ultraviolet light to disarm them.
The study, published in the journal ACS ES&T Air, focused on inactivating allergens by altering their structure. "If your immune system is used to a swan and you unfold the protein so it no longer looks like a swan, you won't mount an allergic response," explained lead author Tess Eidem.
The team used UV222 light, a wavelength considered safe for occupied spaces because it does not penetrate deeply into skin or eyes. In a sealed chamber, they released aerosolized allergens and turned on four small UV222 lamps. By sampling the air at intervals, they found that the light treatment significantly reduced "immunorecognition"—meaning antibodies no longer recognized the altered proteins, preventing an allergic reaction. This effective reduction of airborne allergens was achieved in as little as 30 minutes.
"Those are pretty rapid reductions when you compare them to months and months of cleaning, ripping up carpet, and bathing your cat," said Eidem.
The researchers envision this technology being developed into portable devices that people could use when visiting a home with pets or cleaning a dusty room. It could also protect workers in environments with high allergen exposure. With allergies affecting one-in-three people in the U.S., this new approach could provide significant relief and potentially save lives by preventing deadly asthma attacks.