For most people more than half of their natural background radiation dose comes from radon, a radioactive gas that can accumulate in homes, schools and workplaces.

对大多数人来说，他们自然环境辐射剂量的一半以上来自氡—一种可聚集在家庭、学校和工作场所的放射性气体。

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Two test methods, natural radioactive background method and decay method, used to verify the detection limit of radioactive aerosol monitors are studied.

研究了放射性气溶胶监测仪的检测方法，即天然本底检测法和衰变检测法。

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