The commonly cited number that 70% or 80% of house dust is human skin is likely not true for most houses, however. According to a 2009 study of house dust in the U.S. Midwest, 60% of the components of the dust came from indoors, and 40% came from dirt and other materials tracked in from outside. That indoor 60% included everything from organic fibers to building materials, not just shed skin.
11·3 days ago