Radioisotopes in cosmetics

Furuta, Etsuko*; Nakahara, Hiromichi*; Oura, Yasuji*; Hatsukawa, Yuichi; Matsue, Hideaki ; Sakane, Hitoshi*

Cosmetics which declared hormesis effects are available through Internet. The existence of a daughter nuclides of Th and U series were observed by measuring the rays with a high purity Ge detector. In this study, in order to clarify the contents of trace elements, the hormesis cosmetics were analyzed using prompt activation analysis and observed by SEM-EDX. Main elements of the hormesis cosmetics are some rare earth elements such as La, Ce, Sm and Gd. The ratio of Gd/Sm included in all the hormesis cosmetics is 0.70, and the ratio is different from general cosmetics. Furthermore, we evaluated a possibility of radiation exposure. The influence of rays to skin surface from some hormesis cosmetics was, for example, over 50 mSv per year. The addition of the radioisotope to cosmetics is prohibited in some countries by the laws. The examination of the object that should prohibit the addition of the radioisotope is necessary.