Weathering of Fallout

Subjected to weathering by electrodialysis, fallout pellets collected after a nuclear explosion from the area near ground zero released trace amounts of their total beta activity. Airborne fallout collected 612 miles from the test site released 51.8 percent of its Sr90 activity. Aircraft-collected fallout released 40.5 percent of its Sr90 activity when collected from a tower shot and 86 percent when collected from a balloon shot.