We mostly like being right, but we sometimes wish we weren’t. A few days ago we concluded a post) on some scientific background about Polonium-210 by saying this assassination could also become a public health problem. That now seems to be the case, as a trail of radiation is being found in the victim’s wake. UK authorities are scrambling to track down anyone who might be exposed and establish where the contamination is.
Several British Airways planes on the Moscow – London route have been impounded after it was reported traces of radiation had been found aboard. The UK authorities are trying to track down the passengers of the planes to assess whether any exposure occurred while aboard. A hotel in a rural area has been cordoned off (allegedly because of a connection to the ongoing investigation) and the British Home Secretary said that 12 of 24 sites examined for traces of radiation tested positively. Two individuals who were with the victim just before he became ill were also said to be excreting Po-210 in their urine (CNN).
Meanwhile the autopsy of the Polonium-210 poisoned Russian dissident Alexander Litvinenko was set for yesterday. The pathologists were expected to wear full radiation protection gear because of the danger of being contaminated with Litvinenko’s blood and tissues which likely still contain dangerous amounts of the strong alpha-emitter (for background see posts here and here). UK Polonium-210 expert Nick Priest estimates that Litvinenko’s dose was probably on the order of a few micrograms, which could have been slipped into his food or drink as a soluble salt (New Scientist). The thirty day course of his illness is typical for acute radiation poisoning where fast growing cells in the gastrointestinal tract and bone marrow are killed leading to lethal complications. The biological half life of Polonium-210 is about 30 days, so a microgram or more would be expected to be in his body at the time of necropsy (New Scientist).
Recovery of Polonium and any other heavy metals from Litvinenko’s body might also enable investigators to tell something about the source of the Polonium:
The team should take samples from the liver, spleen, kidney, lung and other tissues, reduce them to ash, and test them with an alpha spectrometer, says [Dudley Goodhead, former director of the British Medical Research Council's Radiation and Genome Stability Unit at Harwell in Oxfordshire]. That should reveal what dose of polonium Litvinenko received, and whether it was in particles or soluble.
Combined with tests for beta and gamma emissions, the samples will also reveal what other radioactive elements are present, if any, and that could point to the polonium’s source. If it was diverted from the eight grams Russia sells to the US each year, for use in anti-static devices, the mix of elements should match.
If it was produced by bombarding bismuth with neutrons in a research reactor, some of the bismuth, and its daughter product, thallium, could remain. And if it was isolated from the rogue’s gallery of radiochemicals in nuclear reactor waste it could be accompanied by ruthenium, and even plutonium. (New Scientist)
As we explained in our earlier posts, alpha emitters are not dangerous as long as they remain outside your body. However if you ingest them or breathe them they can wreak havoc. It is unclear to us how the radiation trail is being established because ordinary Geiger counters don’t pick up pure alpha emitters except with special probes directly over the sample. Most likely authorities are vacuuming areas like plane cabins or bathrooms and assaying the collected particles. This would also allow them to determine what kind of radioactive material is producing the radiation.
There is probably not much risk to the general public if the radioactive wake is from Litvinenko’s excretions and sweat as he moved through London after being poisoned and prior to his confinement in the hospital. But the source of the poison and the poisoner still are unknown. Assuring the safety of the environment and verifying that those potentially at risk are not sick will be a major and costly public health exercise for authorities in the UK and possibly elsewhere, since international travel is involved.
Like the anthrax attacks in the US in 2003, episodes like this not only stress the public health system but show how fragile it is. At that time, much of the US public health system ground to a halt as authorities expended untold effort responding to “white powder” calls. It will be of interest to see how well the UK public health system copes with this extraordinary event. It may be a wake-up call that they aren’t ready for other extraordinary events.
Like an influenza pandemic.