Purpose

In this study, measurements of radon concentrations and estimation of exhalation rates were carried out in soil around buildings within Lagos State in order to determine the contribution to indoor radon concentrations from the soil, and determine the influence of soil moisture on the exhalation rates.

Methods

Fifty-four samples were collected randomly with 27 measured as wet samples and 27 dried before measurements so as to account for the moisture content. Passive measurement method, using cover cup technique with solid state nuclear track detectors, CR-39, was employed.

Results

The results showed weak correlations between the concentrations of radon emanated from the soil samples and the indoor radon concentrations. The results obtained suggested lower concentrations of radon emanated from wet soil than dry soil indicating the influence of moisture. The results further indicate that the highest and lowest values as well as the highest mean for both wet and dry soil samples were obtained from the same environment, suggesting that the soil in that environment are of anomalous petrophysical property.

Conclusion

Concentrations of radon emanated from dry soil are higher than in wet soil, suggesting that the presence of moisture may results in reduction of radon concentrations in soil samples. The result of the surface exhalation rates and the mass exhalation rates are in congruent with results obtained for the concentrations of radon emanated from wet and dry soil samples.

中文翻译：

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使用被动测量技术确定拉各斯环境中建筑物周围土壤的氡呼出率。

目的

在这项研究中，在拉各斯州建筑物周围的土壤中进行了氡浓度的测量和呼出率的估计，以确定土壤对室内氡浓度的贡献，并确定土壤水分对呼出率的影响。

方法

随机采集了 54 个样品，其中 27 个为湿样，27 个在测量前干燥，以说明水分含量。采用被动测量方法，使用带有固态核轨道探测器 CR-39 的盖杯技术。

结果

结果表明，土壤样品中的氡浓度与室内氡浓度之间存在弱相关性。获得的结果表明，从湿土壤中散发出的氡浓度低于干土壤，表明水分的影响。结果进一步表明，湿土和干土样品的最高值和最低值以及最高平均值均来自同一环境，表明该环境中的土壤具有异常的岩石物理特性。

结论

从干燥土壤中散发出的氡浓度高于潮湿土壤，这表明水分的存在可能导致土壤样品中氡浓度的降低。表面呼出率和质量呼出率的结果与从湿土和干土样品中散发的氡浓度得到的结果一致。