fallout; deposited matter
Technical term for particulate matter that settles from the atmosphere, especially radioactive fallout. Used in environmental and nuclear contexts.
原発事故後、降下物の調査が行われた。
After the nuclear accident, surveys of fallout were conducted.
Fallout may contain radioactive materials.
radioactive fallout
Compound of 降下 (こうか, 'falling, descent') and 物 (ぶつ, 'thing, matter').