“…Natural radionuclides from different sources in the environment, even in our bodies can originate from weathering of the earth's crust (rocks, soils, ores), food consumption, mining activity, and fertilizer materials (Azeez et al 2019, Querfeld et al 2019, Takagi et al 2019, Van et al 2020a, 2020b, 2020c, Loat et al 2021, Van et al 2021a, 2021b, 2021c, 2021d). In the air, radionuclides such as 222 Rn and 220 Rn originate from the alpha decay of 226 Ra in the 238 U series and 228 Ra ( 224 Ra) in the 232 Th decay series, respectively (Omori et al 2016).…”