According to another article the glass wall of the vial stops the radiation. https://www.argonelectronics.com/blog/litvinenko-and-the-perfect-radioactive-poiso

According to another article the glass wall of the vial stops the radiation. https://www.argonelectronics.com/blog/litvinenko-and-the-perfect-radioactive-poison-polonium-210 https://www.argonelectronics.com/blog/litvinenko-and-the-per...