Residents in eastern Los Angeles and the San Gabriel Valley experienced the highest levels of air pollution during the first two days of the fire. The toxic emissions, including lead and other heavy metals, pose potential health risks, particularly to vulnerable groups such as children. Scientists have called for further epidemiological studies to assess the long-term health impacts of this intense exposure. The presence of older homes with lead-based paints and brominated flame retardants may have contributed to the high toxicity levels.