Radiological characterization of pharmaceutical and cosmetic clays

Natural radionuclide activity concentration (235U, 238U, 234U, 230Th, 226Ra, 232Th, 228Th, 228Ra and 40K) in clay materials used for cosmetic and medical purposes was determined by alpha and gamma spectrometry. The activity concentration resulted in the range of 0.71 and 4.42 Bq kg−1 for 235U, 15.1–91.4 and 15.3–81.6 Bq kg−1 for 238U and 234U, respectively, 18.7–72.4 Bq kg−1 for 230Th, 27.6–59.7 for 226Ra, 7.80–55.0 and 8.76–58.1 for 232Th and 228Th, 8.60–66.9 Bq kg−1 for 228Ra and 151.6–1,459 Bq kg−1 for 40K. In an oral treatment, the intake was calculated and for some radionuclides the results were higher than the annual dietary intake.