A survey of toxins attributed to Soviet and Russian security services

The deliberate use of toxic substances by state intelligence services is not a matter of mere spy-craft legend. From the slow, inscrutable killing of dissidents in the Cold War, to modern attempts at assassination or incapacitation that have taken place in public places, the historical record contains a number of distinct agents and methods that have been publicly attributed, on varying degrees of evidence, to Soviet or Russian services. What follows is a sober catalogue of the better-documented cases and classes of agents, together with a non-technical account of the symptoms they produce and the general principles of medical response. I avoid operational detail; the purpose here is forensic and journalistic: to explain what was used, what it does to human bodies, and what medicine can — and cannot — do.

1. Organophosphorus “Novichok” nerve agents (and other military nerve agents)

Background and notable cases

A-series nerve agents commonly called “Novichok” were developed in the late Soviet period and came to international attention after high-profile poisonings in the 2010s. The Salisbury attack on 4 March 2018, in which Sergei Skripal and his daughter were seriously poisoned, and later incidents in the United Kingdom and elsewhere, prompted international investigations and a decision to add Novichok-type chemicals to the Chemical Weapons Convention schedules. The Organisation for the Prohibition of Chemical Weapons and scientific reviews have treated Novichok as a distinct and highly toxic class of organophosphorus nerve agents. 

Typical clinical picture

Nerve agents inhibit acetylcholinesterase, the enzyme that breaks down acetylcholine at nerve junctions. The resulting cholinergic crisis produces the familiar mnemonic effects of DUMBBELS (drooling, urination, miosis and muscle spasm, bradycardia/bronchospasm, emesis, lacrimation, salivation) and rapidly escalates to seizures, respiratory muscle paralysis, coma and death if untreated. Onset and severity depend on the compound, route of exposure and dose; some Novichok-type agents are unusually persistent in the environment, which complicates response and cleanup. 

Medical response

Emergency care is life-saving. Treatment rests on three pillars: immediate removal from further exposure and professional decontamination, anticholinergic therapy to counteract excess acetylcholine, and measures to reactivate the inhibited enzyme where possible. Anticholinergic drugs (for example, atropine) and oxime reactivators (for example, pralidoxime or related compounds) are the recognised medical countermeasures; seizure control and respiratory support are frequently required. These are hospital interventions and must be delivered by trained clinicians; they are not matters for improvised self-treatment. 

2. Ricin and other plant-derived protein toxins

Background and notable cases

Ricin is a potent protein toxin extracted from castor beans and has appeared in espionage and terror-related cases for decades. The famous assassination of Georgi Markov in 1978 — the “umbrella” killing in London, conventionally associated with a ricin pellet — remains a paradigmatic Cold War example often linked to Eastern bloc security services. Ricin has no specific, widely available antidote and is better known for its historical use in targeted attacks than for utility as a mass weapon. 

Typical clinical picture

Effects depend upon route. Inhalation produces respiratory distress, cough and fever, progressing to pulmonary oedema and respiratory failure. Ingestion causes severe gastro-intestinal disturbance, profuse vomiting and diarrhoea, dehydration, and ultimately multi-organ failure. Injection (as in the Markov case) can cause rapid local pain followed by systemic collapse. The latency and course vary with dose and route. 

Medical response

There is no specific antidote in routine clinical use. Management is supportive: airway and respiratory support for inhalational exposure, vigorous fluid resuscitation and organ support for systemic effects, and decontamination where appropriate. Because ricin is a protein, research into vaccines and antitoxins exists, but these are not standard, widely deployable countermeasures. 

3. Radioactive isotopes: polonium-210

Background and notable cases

The polonium-210 poisoning of Alexander Litvinenko in London in 2006 is the best documented example of a radioactive assassination in recent memory. UK public inquiries, clinical case reports and legal findings established that ingestion of polonium-210 caused his fatal radiation sickness, a conclusion later reinforced by international judicial findings. Polonium is notable both for its lethality in small quantities and for the complex forensic and public-health implications of radioactive contamination in urban settings. 

Typical clinical picture

Early symptoms may mimic ordinary infections or conventional poisoning: nausea, vomiting, abdominal pain and malaise. Progressive exposure produces bone-marrow suppression (leading to infection and bleeding), loss of hair, gastrointestinal mucosal damage and multi-organ failure — the clinical syndrome of acute radiation sickness. Because alpha radiation (the form emitted by polonium-210) is not deeply penetrating, the danger can be especially severe if the isotope is ingested or inhaled. 

Medical response

Treatment is largely supportive and specialised. Measures aim at reducing further absorption where possible, treating infections and bleeding due to bone-marrow failure, and using chelating or chelator-like agents in experimental or exceptional circumstances. The clinical literature cites certain chelating agents that have been used or considered, but polonium poisoning is medically grave and complex; optimal management requires specialist nuclear-medicine and haematology expertise. Forensic identification and public-health containment are additional, non-medical imperatives in such cases. 

4. Chlorinated dioxins and “environmental” toxicants (example: TCDD in the Yushchenko case)

Background and notable cases

In 2004 Viktor Yushchenko, a Ukrainian presidential candidate, became seriously ill during the campaign and later showed the skin condition chloracne. Analyses by independent toxicologists identified greatly elevated levels of TCDD dioxin in his blood — a finding widely reported in scientific and medical outlets and one of the best documented modern cases of political poisoning with a persistent environmental toxin. Acute dioxin poisoning is, however, rare and usually associated with industrial accidents rather than targeted assassinations. 

Typical clinical picture

High-dose dioxin exposure produces severe systemic illness with chloracne, hepatic dysfunction and other systemic effects. Chronic low-dose exposure is associated with long-term health risks including carcinogenesis; acute, large-dose exposures give rise to dramatic clinical pictures that require specialist management. 

Medical response

Management is supportive and symptomatic. There is no simple antidote for dioxin; long-term monitoring and treatment of organ dysfunction are the clinical mainstay. Public-health measures and removal from continued exposure are important parts of the response. 

5. Sedatives, heavy metals and infectious agents alleged or rumoured in smaller cases

Background and cautionary note

Historical and anecdotal reports have referenced substances such as chloral hydrate and various heavy metals (for example, thallium) or even enteric infections as tools of covert incapacitation; some alleged cases concern food- or drink-borne administration of sedatives (e.g. Rohypnol, a powerful colourless and odourless benzodiazepine typically placed in a victim's drink), or the deliberate introduction of bacterial enteric pathogens such as bacillary dysentery (again typically administered in a drink).

In many instances the evidence is fragmentary or contested, and good-quality forensic confirmation is lacking. It is therefore important to distinguish between well-established, forensically confirmed uses (above) and more speculative or alleged incidents. The epidemiology and clinical management of bacterial infections or heavy-metal poisoning are well established in medicine, but such conditions are ordinary medical problems as often as they are instruments of clandestine harm. For the purposes of this overview I do not rely upon unproven rumours (for example the rumour that all FSB agents carry phials of bacillary dysentry when travelling abroad); where a documented forensic conclusion exists, I have cited it. 

Clinical notes in brief — what clinicians do, and what they do not tell the public

• Rapid triage and hospitalisation are essential when a targeted poisoning is suspected. For many agents the single most important interventions are supportive care (airway, breathing, circulation), prevention of further exposure by professional decontamination, and early transfer to centres with toxicology, critical-care and, if relevant, nuclear-medicine expertise. 

• For nerve agents, recognised antidotes exist and are used by emergency services; these are medical countermeasures that require immediate professional administration and monitoring. For some classical poisons, specific antidotes (for example, certain metal chelators, or agents such as Prussian blue for particular metal exposures or cyanide poisoning) are known to medicine, but their use is specialist and context dependent. For a number of potent toxins — ricin, polonium and many others — there is no simple, guaranteed cure and treatment is primarily supportive. 

  
  

• Public guidance in the wake of a suspected poisoning necessarily stresses evacuation of at-risk locations, professional decontamination, and rapid clinical evaluation. Attempting to treat or diagnose such poisonings without medical supervision is dangerous and may hinder later forensic analysis. Emergency responders follow well-rehearsed hazardous-materials and clinical protocols; such protocols are deliberately technical and are not suitable for lay replication. 

Legal, ethical and political dimensions

The use of toxic agents for political killing or attempted assassination is a criminal act and, when the substances involved are chemical weapons, a violation of international law and treaty obligations. The cases listed above have produced international outrage, diplomatic sanctions and, in some instances, formal changes to multilateral instruments — including the extension of Chemical Weapons Convention schedules to encompass certain Novichok-type agents after the Salisbury episode. The forensic and judicial processes surrounding these incidents are frequently contested, but the aggregate picture is clear: states may weaponise toxicology, with consequences that reach far beyond the individual victim. 

Conclusion

The catalogue of toxins associated with Soviet and Russian intelligence activity includes classic Cold War innovations and more recent, shocking uses of modern nerve agents and radioactive isotopes. The common thread is the deliberate targeting of individuals by means that often leave a complex forensic trail and that impose serious public health, legal and diplomatic consequences. From a medical point of view, responses are typically demanding: early recognition, professional decontamination, aggressive supportive care, and in some cases the use of specialised antidotes. From a policy point of view, these incidents have fuelled international efforts to tighten the prohibition and control of chemical agents and have shown the difficulties — political, scientific and practical — of attributing and preventing state-sponsored poisonings.

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Editor's note: nothing in this article should be considered as a substitute for expert medical advice.