It rises from swamps, forests, deserts and the oceans. Our bodies are surrounded by a personal cloud of it. A certain scent, a single whiff of which can launch a thousand flashbacks—it isn’t air. It’s dust and it’s everywhere. Everything in the galaxy and beyond, including the neurons that manufacture our thoughts, has congealed from space dust, a hundred tons of which continue to fall to earth daily.
No wonder a person could write a whole book about dust. No wonder that dusty tome is such an interesting read.
Holmes considers any particle smaller than half the width of a coarse human hair to be dust. The tiniest motes could be thousands of times smaller than the largest ones.
The best soils are made of dust which itself consists of bits of animal, vegetable, mineral or chemical material which could have come from anywhere. Consider Caribbean islands. They formed when tectonic forces uplifted coral reefs in the Caribbean Sea. Even though erosion ground the surface of exposed reefs to dust, nothing will grow in such “soil.” Yet tropical forests eventually sprouted there, in dust that has been rising from Saharan windstorms for the past 750,000 years and riding atmospheric currents around the globe.
Humans evolved with dust. For eons, most of the ubiquitous dust never made it past people’s nose hairs and sticky mucus. Lungs and bronchial tubes could encapsulate and expel the rest. Dust from recent human activity is becoming increasingly troublesome, however. Such dust might be too small for our nasal passages to trap. Some types, such as particles of DDT or PCBs, or fine silicates that arise when stone is cut can be extremely harmful. Humans have also altered the concentrations of long-existing deadly dusts such as asbestos, lead, coal and everything radioactive, exposing themselves to increased concentrations of dangerous dust. There is even evidence that you could harm yourself by extinguishing a scented candle improperly.
Is this human-created dust at the root of the increasing incidence of asthma in the developed world? Some researchers think so and warn parents to keep their babies off the living room rug. Others suggest that hyper-hygienic practices prevent children from being exposed to the dust that will properly stimulate their immune systems and safeguard them from asthma.
In this book, Hannah Holmes takes you on a complete tour of the familiar world—the large and small, the near and far, the past and future—always inviting you to consider it in terms of dust. The more you think about dust, the more you will be amazed by it. Every line of this book brings a new piece of information, and each mote of it one you will be delighted to discover.