Fig. 1: Time series of outdoor and indoor PM2.5 concentrations in two representative homes during the observation period (December 18, 2024 to February 5, 2025).
The timeline covers three weeks before the fire (grey shading), active fire phase with visbile urban smoke (red shading), three weeks of late fire phase (pink shading), and five days after the fire was officially fully contained (green shading). a A home without a HEPA filter and b A home with HEPA filter. Outdoor PM2.5 is shown in solid black line; indoor PM2.5 in brown (sham home) or blue (HEPA home). All concentrations represent hourly averages. Indoor source peaks are marked in the plots but were removed in statistical analysis. Text boxes to the right of each panel indicate filter status, Air conditioning, house type, and room volume.
