Bulgarian umbrella effectively used to assassinate a Bulgarian journalist by poisoning him with ricin delivered through the tip of an umbrella. Bulgarian umbrella A Bulgarian umbrella is an umbrella with a hidden pneumatic mechanism which injects a small poisonous pellet containing ricin. It has a hollowed stalk into which the pellet neatly sits. Such an umbrella was allegedly used in and named for the assassination of the Bulgarian dissident writer Georgi Markov on 7 September 1978 (the birthday of the Bulgarian State Council chairman Todor Zhivkov, who had often been the target of Georgi Markov's criticism) on Waterloo Bridge in London. Markov
Ricin would generate enough heat to denature it. Once deployed, an area contaminated with ricin remains dangerous until the bonds between chain A or B have been broken, a process that takes two or three days. In contrast, anthrax spores may remain lethal for decades. Jan van Aken, a German expert on biological weapons, explained in a report for The Sunshine Project that Al Qaeda’s experiments with ricin suggest their inability to produce botulinum or anthrax. A biopharmaceutical company called Soligenix, Inc. has licensed an anti-ricin vaccine called RiVax™ from Vitetta et al. at UT Southwestern. The vaccine is safe and