Radioactivity levels in peloids used in main Cuban spas

Radioactivity (226Ra, 137Cs, 232Th and 40K) levels in peloids from some Cuban spas (San Diego, Elguea, Santa Lucía and Cajío) have been studied. The radionuclide concentration ranges in peloids on Bq kg−1 dry weight varied as follows: 226Ra = 6–1800, 137Cs = < 1.6–5.0, 232Th = 6–38 and 40K = 47–365, and are in the same order of concentrations reported for therapeutic peloids used worldwide. The estimated annual equivalent dose in 226Ra-enriched peloids, considering the short exposition times associated with the usual therapeutic practices in Cuban spas, is well below accepted equivalent dose values to the skin for members of the public. Therefore, radioactivity levels present in peloids from the studied Cuban spas are not significant and do not represent an impediment for its use with therapeutic purposes.