Pb-210 + Ra-226

Plumbum-210 + Radium-226

Natural

α, β, γ radiation

Half-life: 22.3 years
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Main emission lines: 47keV
Decay chain: Ra-226
Related lines: 78keV, 186keV, 242keV, 295keV, 351keV, 609keV, 1120keV, 1760keV, 2200keV

Where detected

This isotope is almost always present in a mixture with other isotopes characteristic of the decay chain of uranium, radium, or radon. It can be found separately in objects that have been exposed to incredibly high levels of radon for a long time, for example, on the internal parts of watches where paint based on Radium-226 was used.

Pb-210

Plumbum-210

Natural

α, β, γ radiation

Half-life: 22.3 years

Main emission lines: 46.5 keV

Where detected

Pb-210 is an environmental radionuclide with a half-life of 22.3 years, formed in the atmosphere via radioactive decay of radon (Rn-222). Rn-222 itself is a noble gas with a half-life of 3.8 days and is formed via radioactive decay of uranium (U-238) contained in the Earth crust from where it constantly emanates into the atmosphere. Pb-210 atoms attach to aerosol particles, which are then deposited on glaciers via scavenging with fresh snow. Due to its half-life, ice cores can be dated with this radionuclide over roughly one century, depending on the initial Pb-210 activity concentration.