Abstract Gamma ray spectra of natural radioactivity from 238U, 232Th, and 40K in sediments and water samples from rivers in eleven oil-producing and two non-oil producing communities in Delta state of Nigeria have been evaluated using gamma-ray spectrometer with the hyper-pure germanium detector. Measured activity concentrations in water samples ranged from 1.17 Bq L−1 to 14.65 Bq L−1 for 40K; 0.26 Bq L−1 to 3.11 Bq L−1 for 232Th and 1.05 Bq L−1 to 5.58 Bq L−1 for 238U. The specific activity due to 232Th is found to be relatively low compared to that of 238U in all the water sample investigated. In the sediment samples, activities of 40K ranged from 32.47 Bq kg−1 to 525.1 Bq kg−1, 232Th ranged from 6.31 Bq kg−1 to 19.33 Bq kg−1 and values of 238U ranged from 4.45 Bq kg−1 to 18.69 Bq kg−1. The radiological hazard indices reported in this work include absorbed dose (D), radium equivalent dose (Req), external and internal hazard indices (Hex, Hin), annual effective dose equivalent (AEDE), lifetime average annual dose associated with water resources (LAAD), and excess lifetime cancer risk (ELCR). The values of the radiological hazard indices obtained were observed to be lower than limits internationally reported for both water and sediment, but observed concentration values at the oil-producing study areas are in most cases higher than values from the non-oil producing sites.

中文翻译：

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尼日利亚三角洲部分产油社区河水和沉积物放射性参数评估

摘要 使用伽马射线光谱仪和超强伽马射线光谱仪对尼日利亚三角洲十一个产油社区和两个非产油社区的河流沉积物和水样中 238U、232Th 和 40K 的自然放射性进行了伽马射线谱评估。纯锗探测器。40K 水样中测得的活性浓度范围为 1.17 Bq L-1 至 14.65 Bq L-1；232Th 为 0.26 Bq L-1 至 3.11 Bq L-1，238U 为 1.05 Bq L-1 至 5.58 Bq L-1。在所有研究的水样中，发现由 232Th 引起的比活度与 238U 的比活度相比相对较低。在沉积物样本中，40K 的活度范围为 32.47 Bq kg-1 至 525.1 Bq kg-1，232Th 的范围为 6.31 Bq kg-1 至 19.33 Bq kg-1，238U 的值范围为 4.45 Bq kg-1 至 18.69 Bq公斤-1。本工作报告的放射危害指数包括吸收剂量（D）、镭当量剂量（Req）、外部和内部危害指数（Hex、Hin）、年有效剂量当量（AEDE）、与水资源相关的终生平均年剂量（ LAAD) 和超额终生癌症风险 (ELCR)。观测到的放射性危害指数值低于国际报告的水和沉积物限值，但在产油研究区观测到的浓度值在大多数情况下高于非产油地点的值。