From what I heard from Army acquaintances, the sand storms meant daily or oftener cleaning of air filters on the vehicles and other equipment, especially small arms.
I was in a gas station in Yakima WA three months after Mt. St. Helens blew.
There were pictures on wall showing how they kept the sheriff’s cars running during the ash fall.
A clothes dryer exhaust hose was duct taped to the air intake then run down the side of the car and attached to the rear. The end of the hose was covered with a pantyhose.
The guy at the station said they had to change the pantyhose every 1/2 hour.