What is Dust?

Types of DustWhat is dust? Most people are of course familiar with the term “dust,” but when it comes to giving it a precise definition that is objective, accurate, or scientific if you will, many would not be able to tell you what the different types of dust are, what the range of elements that dust can be composed of is, how dust and the living world interact on a biological level, or what the adverse health effects of extended exposure to house dust are.

So let’s clear some of the confusion and state that dust is any solid particle in the air that is under 500 micrometers in diameter. That being said, there are different kinds of dust that are common both inside our buildings, as well as out in the atmosphere, and even in outer space; the physical and chemical composition of dust varies considerably. Generally speaking, dust can be classified into three broad categories depending on where it is found: there is domestic dust (or house dust), which is found in our homes, businesses, and any other building interior. There is also atmospheric dust, in the greater atmosphere of the Earth, natural as well as man-made. And dust can also be found in outer space–think of the famous term “stardust,” or Carl Sagan’s widely recognized assertion that we ourselves were made of “star stuff” (i.e., dust, or particulate matter, that originated from the stars). This type, we can call cosmic dust.

While cosmic dust is not an immediate concern of the ordinary person as house dust, or some of the particulate matter that pollutes the atmosphere, it is nonetheless an essential constitutive element of the cosmos, whose importance has lately been recognized more and more in modern astronomy.

To find out more about the different types of dust, as well as how to fight dust and make your air cleaner or avoid dust exposure and its adverse health effects, check out the relevant pages linked above.