Men and women huddled in their houses, and they tied handkerchiefs over their noses when they went out, and wore goggles to protect their eyes. When the night came again it was black night, for the stars could not pierce the dust to get down, and the window lights could not even spread beyond their own yards. Now the dust was evenly mixed with the air, an emulsion of dust and air. Houses were shut tight, and cloth wedged around doors and windows, but the dust came in so thinly that it could not be seen in the air, and it settled like pollen on the chairs and tables, on the dishes. The people brushed it from their shoulders. Little lines of dust lay at the door sills.

– John Steinbeck

The Grapes of Wrath, Chapter 1. The repetition of the word "dust" helps us visualize how all-pervasive the dust is, both outdoors and indoors. People are forced to stay inside their homes and wear handkerchiefs and goggles to protect themselves from it. But the dust finds its way inside the houses, where Steinbeck uses a simile to compare it to pollen settling on everything. His depiction of the drought and dust storms and the environmental and human catastrophe they brought is as if he was describing a plague of Biblical proportions.