When wildfires began racing through the Los Angeles area on Jan. 7, 2025, the scope of the disaster caught residents by surprise. Forecasters had warned about high winds and exceptionally dry conditions, but few people expected to see smoke and fires for weeks in one of America’s largest metro areas.
Environmental health scientist Yifang Zhu studies air quality at UCLA and began collecting samples from inside and outside homes the day after the fires began. In this Q&A, she describes findings by her team, a consortium of universities and local projects, that are painting a picture of the health risks millions of Los Angeles-area residents faced.
