Over the years there have been holiday periods with many thousands of vehicles disturbing the dune crust at the Oceano Dunes State Vehicular Recreation Area. On those high-usage days, unless there was wind, there was no plume of air pollution. But the next time the wind blew, the dust went into the air and dangerous particulate matter levels rose. It will take time to see the effects on air quality of this induced absence of vehicles on the beach and dunes. It's the perfect opportunity to give the crust time to heal. Let's ask then if when the wind blows, is it safe to breathe downwind. Please see "Danger Downwind" in the documentary series What We Need to Know about Oceano Beach and Dunes at safebeachanddunes.org.