No single case history would do justice to all the complaints involving black particles. Black particles are a common complaint in both the workplace and in the home. Contrary to popular belief black particles do not constitute a unique, single particle type. Combustion particles are typically black but every fuel creates its own unique distribution of particle types as already presented in the case of plant fuels. The combustion need not be local. Soot and charred products can travel considerable distances and deposit over time creating a black particle traffic arteriales nearby. Electric motors generate fine black metal wear and graphite particles that can become a black particle problem. Electric heating elements in baseboard heaters generate both metallic oxides and charred particles in the environment. When an electric heating element first heats up it both chars the particles that collected on the element since its last heating cycle and the element expands thus dislodging the particles into the convective air flow. The odor noticeable when the heater first heats up is the result of this initial burst of charred particles and volatilized pyrolysis products. Many fungal species generate black or dark spores that look black on light surfaces. Computer printers or copy machines can generate large amount of free toner particles. Toner particles can be a significant health risk. This is just a partial list of black particle types common in home and office environments. Each particle type is associated with its own health implications. Charred materials indicate incomplete combustion; carbon monoxide testing may be required. Black spores may be a localized Cladosporium population, possibly a problem; or Stachybotrys, a more serious situation.
At any given location multiple sources of black particles are present. The sample collected must be the black particles that cause the concern and not just any deposit of black particles. Black particles on the bathroom wall, black particles above an electric heating register, black particles on the window sill, and black particles collecting on white plastic surfaces in the kitchen are often all different. If the concern is the black particulate matter in the kitchen then that is the sample that should be taken. Sampling the air in this situation will only confuse and complicate the issue. The question in this case relates to a very specific population of surface particles. That is the sample that needs to be analyzed.
Common Black Particles in Homes