Relationship between radium isotopes and their chemical analogues in a hot spring area in Taiwan

A gamma-ray spectrometry was used to measure radium isotopes in a radium-enriched hot spring area. The activity of 224 Ra was highly correlated with 228 Ra in water caused by their same chemical behavior and the origin of the decay series chain. Besides, the radioactivity between radium isotopes ( 226 Ra, 228 Ra) and the selected chemical analogues in sludge exhibited moderate (Ba and Sr) to strong (Pb) correlations according to linear regression analysis. In contrast, there is less correlation between radium isotopes and 40 K. These results reveal that radium isotopes may be transported and distributed together in the environment.