Po-210 is an isotope of regular polonium; it’s a decay product of notably uranium-238.
(I’ve had some radiation safety training in the US as well as in the UK. I’ve worked with non-radioactive isotopes of the rare earths, a lifetime ago, in such low concentrations in seawater that avoiding contamination was a necessity. So I worked in a clean lab and learned lab techniques and habits that help you avoid contamination. Back then, I had no idea that what I was learning was so widely applicable, in all sorts of settings. Having the basic insights and awareness of how contamination happens and how you can avoid it is so useful.)
(Geologists use a lot of this stuff, too. Isotopes, I mean. Knowledge about isotopes, radioactivity and decay and all that.)
PS As you can tell by watching this documentary, sane, well-functioning, well-thinking, modern-day English people clearly do exist. 🙂 There are even a few “uppity” females in it too, the kind that I know from other countries. Scientists.