The use of radon as tracer in environmental sciences

Radon can be used as a naturally occurring tracer for environmental processes. By means of grab-sampling or continuous monitoring of radon concentration, it is possible to assess several types of dynamic phenomena in air and water. We present a review of the use of radon and its progeny at the University of Cantabria. Radon can be an atmospheric dynamics indicator related with air mass interchange near land-sea discontinuities as well as for the study of vertical variations of air parameters (average values of different types of stability: 131–580 Bq m −3 ). Concerning indoor gas, we present some results obtained at Altamira Cave (Spain): from 222 to 6549 Bq m −3 (Hall) and from 999 to 6697 Bq m −3 (Paintings Room). Finally, variations of radon concentration in soil (0.3 to 9.1 kBq m −3 ) and underground water (values up to 500 Bq l −1 ) provide relevant information about different geophysical phenomena.