Charred Softwood

Transmitted Brightfield Illumination

The large, well separated pores (circular patterns) identify this fragment as coming from a conifer or softwood tree. The pore structure in this sample is different than that seen in the other example provided in this section of the gallery. The pore stucture is important in helping to determine the species or at least eliminate possible species as a source. The brown coloration indicates the loss of hydrogen in the cellulose that makes up the cell structure of the wood. That is the result in this case of exposure to high temperatures. This type of particle is common where softwoods are used as a fire wood and from forest fires, slash burns, hog fuel boilers, or, more in the past, TPee burners to dispose of waste from lumber mills. Charred wood is one of the more common airborne particles in urban and suburban environments. Indoors it can indicate back-drafting of a fireplace.