Polonium-210: International Public Health Follow-up

BACKGROUND Following a death from radiation poisoning in November 2006, small quantities of Polonium-210 were found at several sites in central London. The Health Protection Agency (HPA) was responsible for the public health follow-up of individuals potentially exposed to this radioactive contamination. This presentation describes the international public health response co-ordinated by the HPA.

METHODS An Overseas Advice team was established to follow up overseas visitors using similar criteria to those applied to UK residents, and to liaise with appropriate overseas authorities. Individuals were identified either through the visitor records of contaminated sites or self-identified via a dedicated email address. Where required, exposures were determined by measurement of the daily urinary excretion of Polonium-210.

RESULTS Altogether 664 persons from 52 countries and territories were identified and assessed according to a hazard exposure and risk assessment algorithm; 168 (25.3%) are known to have had 24-hour urine tests, 274 (41.3%) were assessed to be ‘not-at-risk' and the remainder either declined urine testing or were lost to follow-up. A number of practical lessons were identified including: follow-up difficulties; confidentiality issues; and resource issues.

DISCUSSION The international public health follow-up from this incident concluded in May 2007. The result of risk assessment and urine testing was communicated from many countries to a central database at the HPA, but for other countries the outcome of follow-up remains unknown. This unique incident has demonstrated the ‘added value' of an integrated health protection response and identified lessons that can assist in the formulation of public health policy.