Soil gas 222Rn concentration in northern Germany and its relationship with geological subsurface structures

► 222Rn activity in soil gas was measured across salt structures in northern Germany. ► 222Rn activity ranges up to 105 kBq/m3 across the margins of salt structures. ► Activities caused by moraine boulder material are about 40 kBq/m3. ► We suggest that the salt dome environment has an impact on gas migration. ► A theoretical model was developed which explains the relevant processes.