Given the rather short half-life of thoron (²²⁰Rn), at 56 s, its contribution to radiation exposure is often overlooked. Nevertheless, in a thorium (²³²Th) rich environment potential hazard does exist, in particular regarding prolonged duration exposures to ²²⁰Rn and its short-lived alpha-particle emitting progeny [polonium (²¹⁶Po)]. Herein, concerning the geology and major soil types in the Malaysian state of Perak, an activity concentration map has been established for ²²⁰Rn in soil gas, with the use made of a RAD7 detector and the THORON protocol for in-situ measurements. The detector has been coupled to a soil probe driven to a depth of 0.8 m. The activity concentration of ²²⁰Rn in the soil ranged from undetectable to 563 kBq m⁻³ with a mean value of 38 ± 11 kBq m⁻³. Granite and Triassic-Jurassic formations in the region showed more elevated ²²⁰Rn activity while Quaternary and Silurian formations revealed low ²²⁰Rn values. Moreover, while elevated ²²⁰Rn activity concentrations were found in peat, riverine, and granite source soils, the activity concentrations in marine and other soils were low. A primary map of ²²⁰Rn in the soil gas has been developed based on geogenic impact assessment, with a greater ²²⁰Rn activity concentration in the central part of the state.

^{鉴于钍气 ( 220} Rn)的半衰期相当短，为 56 秒，它对辐射暴露的贡献常常被忽视。然而，在富含钍 ( ²³² Th) 的环境中确实存在潜在危害，特别是在长时间暴露于²²⁰ Rn 及其短寿命 α 粒子发射子代 [钋 ( ²¹⁶ Po)] 方面。在此，关于马来西亚霹雳州的地质和主要土壤类型，已经建立了土壤气体中²²⁰ Rn 的活动浓度图，使用 RAD7 探测器和 THORON 协议进行原位测量。探测器已与驱动到 0.8 m 深度的土壤探头耦合。活性浓度^{土壤中的220} Rn 从检测不到到 563 kBq m ^-3不等，平均值为 38 ± 11 kBq m ^-3。该地区的花岗岩和三叠纪-侏罗纪地层显示出更高的²²⁰ Rn 活性，而第四纪和志留纪地层显示出较低的²²⁰ Rn 值。此外，虽然在泥炭、河流和花岗岩源土壤中发现²²⁰ Rn 活性浓度升高，但在海洋和其他土壤中的活性浓度较低。根据地质影响评估，绘制了土壤气体中²²⁰ Rn的原始图，该州中部的^{220 Rn 活动浓度较高。}