Two wildfires ignited early Tuesday in San Diego, California's Department of Forestry and Fire Protection said. The Lilac Fire had burned about 20 acres at a moderate rate of speed and was zero percent contained, Cal Fire’s San Diego department said in a statement posted on social media.

Dr. Wennberg said that a particulate sampling device about 20 miles south of the Eaton fire had detected high levels of toxins, including lead, chlorine and bromine in the air. Ninety percent of the homes in the Altadena were built more than a half-century ago, when lead paint and asbestos were still used in home construction.

"If fire ignition occurs, conditions are favorable for very rapid fire spread and extreme fire behavior," the NWS warns.