Black Shoe Wear and Charred Wood
This is from an in-home office in Redmond, Washington,
hundreds of miles from the nearest wildfire. The shoe
wear particle is in the upper left. The charred wood (a hardwood) is near the
center. The fungal particle in the lower right would also
appear black without reflected darkfield illumination.
Transmitted Crossed Polarized Light and Reflected Darkfield Illumination
Definition/Function:
Shoe wear particles are common in homes, offices, and classrooms. The "rubber" soles
come in a variety of colors but are typically heavily filled with
mineral fillers. The tapered cylinder shape is typical. Charred wood, to be identified
as such, must be brittle and break with sharp edges.
It must also have sufficient morphology to be identifed as exhibiting wood cellular
structure.
Significance in the Environment:
Indoor environments not exposed to wildfire often contain black particles in excess of
1% of the total particulate matter. The amount of
charred wood alone can exceed 1% in some of these homes, especially if they or their
close neighbors use a fireplace or woodstove.
Characteristic Features:
Associated Particles:
References:
