Assessment of radiation dose to inhabitants from coal ash in main wall material in China

Additional radiation dose to inhabitants living in buildings constructed with wall material containing coal ash were evaluated through the investigations on electricity generation of coal-fired power plants (CFPs), activity concentration of natural γ nuclides in coal ash, comprehensive utilization of coal ash in wall materials in China and the indoor radiation exposure scenarios during 1992-2010. The results showed that: the radiation dose for inhabitants living in these buildings increased with the addition of coal ash in main wall material, which was consistent with the reported data. In China, the total additional annual effective individual dose from wall material containing coal ash was 0.01-0.30 mSv/a higher than that from red bricks, with an average of 0.22 mSv/a; and the internal dose approached to 82%. The additional normalized collective dose during 1992-2010 was approximately (1.92 × 10³)-(5.85 × 10³) man · Sv/GWa. It was also found that the average contribution to the increase of indoor radon concentration from use of main wall material containing coal ash approached to 28%, with a range of 7%-38%. The results obtained in this study provided essential basic data for the utilization policy of coal ash and environmental radiological risk analysis for CFPs. (authors)