Yasser Arafat, former chairman of the PalestineLiberation Organization (PLO), died in November 2004, after a briefillness. Not surprisingly, his death aroused considerablesuspicion, particularly given that his symptoms were somewhatconsistent with acute radiation poisoning. In November 2012,samples of tissue were obtained from his corpse and tested—by threeindependent research groups—for evidence of poisoning by a highlyradioactive isotope of Polonium. The results, though far fromconclusive, suggest that Arafat died as a result of polonium-210poisoning.
Polonium-210 is a short-lived isotope in the uraniumdecay series. Together with thallium-206, polonium-210 is apenultimate daughter product in the 238U → 206Pb decay series.Polonium-210 occurs in trace amounts in uranium ores; annually,about 100 grams of 210Po is produced (synthetically) in reactors.210Po decays to 206Pb via alpha emission with a radiogenichalf-life of 138 days. The ejected alpha particle has an energy of5.3 MeV. The biological half-life of 210Po is about 40 days, i.e.it takes your body about 40 days to excrete half the amount of210Po originally ingested. For the purposes of this class, thefatal internal dose (D50) of radiation from an ingested alphaemitter like 210Po is approximately 0.25 Joule of energy absorbedper kilogram of body mass. (Note: The D50 notation indicates thedosage that proves fatal for half of a population; D50 ~ 0.25 J/kgfor 210Po.) For those interested in dosage units, 0.25 J/kg = 0.25Gy = 5 Sv = D50 for an alpha emitter absorbed internally (Q factorof 20).
1 (20 pts.): Assuming access to a ‘fresh’ poloniumsource, i.e. straight from the reactor, would one microgram (1 μg)of ingested 210Po kill Arafat? (FYI: 1 μg of 210Po is equivalent toapproximately one grain of silt.) If yes, then approximately whattime interval was required to absorb a fatal dose? Note: There istypically a lag time of days to weeks between the time at which afatal dose is absorbed and the actual time of death. Arafat diedabout two weeks after the onset of symptoms. Discuss very brieflysome of the complications we might expect in analyzing Arafat’scorpse for signs of 210Po poisoning in 2012.
1) clear and concise explanations of your reasoning and2) careful calculations using scientific notation. The answershould be presented clearly and logically.
