Aerosol monitoring site collects data in aftermath of urban firestorm

On January 9, approximately a full day after the Eaton fire devastated the foothill area of Altadena, north of the Caltech campus in Pasadena, California, several specialized scientific instruments in a shipping container in Pico Rivera, about 11 miles to the south, detected a spike in atmospheric concentrations, particularly of chlorine and lead—both known to be toxic at low levels. When at their maximum that day, chlorine levels reached about 40 times the normal amount, and lead peaked at more than 100 times the usual level.