Polonium-210

Polonium-210 (²¹⁰Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable ²⁰⁶Pb with a half-life of 138.376 days (about 4+1⁄2 months), the longest half-life of all naturally occurring polonium isotopes (^210–218Po).^[1] First identified in 1898, and also marking the discovery of the element polonium, ²¹⁰Po is generated in the decay chain of uranium-238 and radium-226. ²¹⁰Po is a prominent contaminant in the environment, mostly affecting seafood and tobacco. Its extreme toxicity is attributed to intense radioactivity, mostly due to alpha particles, which easily cause radiation damage, including cancer in surrounding tissue. The specific activity of ²¹⁰
Po is 166 TBq/g, i.e., 1.66 × 10¹⁴ Bq/g. At the same time, ²¹⁰Po is not readily detected by common radiation detectors, because its gamma rays have a very low energy. Therefore, ²¹⁰
Po can be considered as a quasi-pure alpha emitter.