Pure Paradise

You probably don't want to know how much dust, pollen, pesticides, lead, dander and fibers you breathe in on a daily basis. The dust around us, and the dust to which we all return, is a daily reminder that we are clearly a part of this earthly world, even though, as Jesus reminds us, we are citizens of another world.

Dust is our beginning.

It is also, most certainly, our end. "You are dust," said God to Adam, before tossing him out of the garden of Eden, "and to dust you shall return" (Genesis 3:19).

But now, scientists tell us, dust is also a dramatic part of daily living. With every breath we take, we suck in tens of thousands of particles. Although we can't see it, each of us walks the earth in a cloud of dust, shedding fragments of skin and bits of lint torn from our clothes through friction. Some of it is benign, but some of it is deadly: Think of the workers in post offices and Senate buildings who had no idea that they were breathing anthrax spores.

Science journalist Hannah Holmes suggests that by age 6, our children have consumed at least a cup and a half of pollen, pesticides, lead, dander, and fibers. A cup and a half of the minuscule parts and pieces of our crumbling world.

In her book The Secret Life of Dust, Holmes tracks the enormous dust streams that pour across from Saharan Africa,...