Polonium-210 Contamination Information and Updates
The Health Physics Society 
fact sheet
The Health Physics News article Why 210Po?
The Centers for Disease Control and Prevention information sheets
The International Atomic Energy Agency information sheet
The Nuclear Regulatory Commission Web page and fact sheet
NRC Commissioner McGaffigan's Letter to the Editor - The New York Times: Polonium and Terrorism
The Health Protection Agency (HPA) in the United Kingdom has been posting regular updates on the polonium-210 contamination case. These updates are available on the HPA's website and are reproduced here for your convenience. (The HPA describes itself as an independent body that protects the health and well-being of the population. The Agency states it plays a critical role in protecting people from infectious diseases and in preventing harm when hazards involving chemicals, poisons, or radiation occur.)
HPA Updates: