There was a very interesting article on Bloomberg.com over the weekend about wildfire smoke. It began with a question: where does the smoke go when it goes away? You think the wind comes, blows it out of the area, and that's that. But in reality, not so much.
The larger particles tend to come under the control of gravity. They just fall into whatever's beneath them, be it land or water. That's called gravitational settling.
Air currents can also make particles of pollution get stuck in the ground, that's called impaction. Or rain can incapsulate the particles, allowing them to sink into the soil or enter the watershed, in a process called “washout.” They can also evaporate into the clouds and make it back to earth when it rains. And some particles go into our lungs – the most immediate threat to our health.
If there's smoke on your clothes, it could make it into the waterways when you wash them.
Smoke can impact the taste of wine, contaminating its flavor along with the grapes, that's called “smoke taint.”
The bottom line, according to a researcher at UC Davis' Air Quality Research Center, is that pollution is very hard to destroy. It never goes away. It always goes somewhere.