Gross alpha measures radioactivity from natural deposits and industrial processes, excluding radon and uranium. It indicates potential cancer risk from radiation exposure.

Gross alpha is a measure of radioactivity from alpha particles emitted by certain elements. It occurs naturally in rocks and soil, but can also come from industrial processes like mining or nuclear power. Water becomes contaminated when these elements leach from surrounding geology or through industrial discharges. Testing involves a method called scintillation counting, which detects alpha particle emissions. The measurement excludes radon and uranium to focus on other radioactive elements.