Gamma radiation measurements and dose rates in commercially-used natural tiling rocks (granites)

J Environ Radioact. 2003;70(3):223-35. doi: 10.1016/S0265-931X(03)00106-1.

Abstract

The gamma radiation in samples of a variety of natural tiling rocks (granites) imported in Cyprus for use in the building industry was measured, employing high-resolution gamma-ray spectroscopy. The rock samples were pulverised, sealed in 1-l plastic Marinelli beakers, and measured in the laboratory with an accumulating time between 10 and 14 h each. From the measured gamma-ray spectra, activity concentrations were determined for (232)Th (range from 1 to 906 Bq kg(-1)), (238)U (from 1 to 588 Bq kg(-1)) and (40)K (from 50 to 1606 Bq kg(-1)). The total absorbed dose rates in air calculated from the concentrations of the three radionuclides ranged from 7 to 1209 nGy h(-1) for full utilization of the materials, from 4 to 605 nGy h(-1) for half utilization and from 2 to 302 nGy h(-1) for one quarter utilization. The total effective dose rates per person indoors were determined to be between 0.02 and 2.97 mSv y(-1) for half utilization of the materials. Applying dose criteria recently recommended by the EU for superficial materials, 25 of the samples meet the exemption dose limit of 0.3 mSv y(-1), two of them meet the upper dose limit of 1 mSv y(-1) and only one clearly exceeds this limit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Construction Materials*
  • Environmental Exposure*
  • Gamma Rays*
  • Materials Testing
  • Radioisotopes / analysis
  • Reference Values
  • Safety
  • Silicon Dioxide*

Substances

  • Radioisotopes
  • granite
  • Silicon Dioxide