Natural radioactivity levels in bottled water in Spain

Spain is a country rich in mineral springs. A nationwide study on the natural radioactivity has been made to determine the gross-α and gross-β activities in bottled water. These measurements are important for extracting radiological information of the activity present in a sample. Of all samples collected, only 26.2% have an α-activity higher than 100 mBq/l, and none of them have a β activity higher than 1000 mBq/l. An explanation for the different α and β activities in bottled water that relates to the geological composition of the source is suggested.