Duct Dust The inside of a duct before it was cleaned by Rick Hughes (Ductdusters, Winchester, MA). The dust consists mostly of fibers and skin scales. Mites and booklice forage in duct dust while hungry spiders bide their time. IMAGE COPYRIGHT RICK HUGHES, 1995.
			Furnace Blower A dirty furnace blower before it was cleaned by Rick Hughes (Ductdusters, Winchester, MA). Note the reddish discoloration due to rust. Rusting means that water, probably from a leaking AC condensate pan or furnace humidifier, wet the dust and led to mold growth. IMAGE COPYRIGHT RICK HUGHES, 1995.
Photos can be reprinted with permission from May Indoor Air Investigations LLC .............