Assessment of radiological hazards of travertine rocks as building materials

Although travertine is now widely used as a building material, the effects of its radiological hazards to public health should be a matter of concern. Therefore, this study aimed to determine its radiological parameters with regard to human health. In this research 10 travertine samples were collected from exploitation zone in Haji Abad Mine in Mahallat, Iran. Specific radionuclide activities were determined by gamma spectrometry using a high purity germanium detector. In addition, radiological parameters, such as radium equivalent, air doses, internal and external risk factors (Hin, Hex), yearly gonadal dose equivalent (AGDE), and additional cancer risk (ELCR) throughout life were calculated. The specific activities of 226Ra, 232Th, and 40K radionuclides ranged within 3.08-9.16, 1.22-6.45, and 20.15-91.04 Bq/kg, respectively. The obtained means of internal and external annual effective dose of samples were 0.03 and 0.007 mSv/y. External and internal hazard indices for samples were within the range of 0.003-0.01 and 0.01-0.03, respectively. The results of this study show that the amount of radionuclides in travertine rocks is very small compared to its global average in soil and rock. Therefore, it is suggested to use travertine as a building material, which is not a threat to public health.