The natural radioactivity in coal fly ash and natural pozzolan Portland cement samples produced in Spain was measured by gamma spectrometry. Activity concentrations of 226Ra, 232Th and 40K ranged from 15.7 to 88.3 Bq kg−1, from 12.8 to 81.0 Bq kg−1 and from 37.0 to 678.0 Bq kg−1, respectively. The radiological hazards samples owing to the mentioned natural radioactivity were inferred from determinations of the activity concentration index, I, absorbed dose rate, Dext, and annual effective dose, Ep, which falls within 0.20 mSv to 0.87 mSv (coal-cement) and 0.18 mSv to 0.50 mSv (pozzolan-cement) (≤ 1 mSv, threshold criterion). Therefore, these cements are proper to be used for building purposes as result of their radiological assessment.

中文翻译：

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评估由粉煤灰和天然火山灰波特兰水泥引起的天然放射性和辐射危害

西班牙生产的粉煤灰和天然火山灰波特兰水泥样品中的天然放射性是通过伽马光谱法测量的。226Ra、232Th 和 40K 的活性浓度范围分别为 15.7 至 88.3 Bq kg-1、12.8 至 81.0 Bq kg-1 和 37.0 至 678.0 Bq kg-1。由于所提到的天然放射性，放射性危害样本是根据活度浓度指数 I、吸收剂量率 Dext 和年有效剂量 Ep 的确定推断出来的，Ep 落在 0.20 毫希沃特至 0.87 毫希沃特（煤水泥）和 0.18 毫希沃特之间。 mSv 至 0.50 mSv（火山灰水泥）（≤ 1 mSv，阈值标准）。因此，根据放射学评估，这些水泥适合用于建筑目的。