Assessing public health risk in the London polonium-210 incident, 2006

Mr Alexander Litvinenko died in a London hospital on 23 November 2006, allegedly from poisoning with the radionuclide polonium-210 ((210)Po). Associated circumstances required an integrated response to investigate the potential risk of internal contamination for individuals exposed to contaminated environments.

Descriptive study.

Contaminated locations presenting a potential risk to health were identified through environmental assessment by radiation protection specialists. Individuals connected with these locations were identified and assessed for internal contamination with (210)Po.

In total, 1029 UK residents were identified, associated with the 11 most contaminated locations. Of these, 974 were personally interviewed and 787 were offered urine tests for (210)Po excretion. Overall, 139 individuals (18%) showed evidence of probable internal contamination with (210)Po arising from the incident, but only 53 (7%) had assessed radiation doses of 1mSv or more. The highest assessed radiation dose was approximately 100mSv.

Although internal contamination with (210)Po was relatively frequent and was most extensive among individuals associated with locations judged a priori to pose the greatest risk, a high degree of assurance could be given to UK and international communities that the level of health risk from exposure to the radionuclide in this incident was low.