Deliberate events: When malicious acts target public health
Deliberate events: How chemical, biological, and cyber threats challenge global health security
The hospital emergency room in Salisbury, England, erupted into controlled chaos on March 4, 2018.
Two patients arrived unconscious, frothing at the mouth, pupils constricted to pinpoints. The medical team recognized the signs immediately: nerve agent poisoning. But this wasn’t an industrial accident or environmental contamination.
It was a deliberate event—the intentional use of a military-grade nerve agent called Novichok to poison former Russian spy Sergei Skripal and his daughter Yulia in what British authorities would later confirm as an assassination attempt.
Healthcare workers treating the victims had to be decontaminated. The entire area where the attack occurred required extensive cleanup. First responders fell ill. The incident demonstrated how a single deliberate event can transform a quiet English town into a hazardous zone requiring international health and security coordination.
This is the reality of deliberate events—malicious acts with intentions to cause harm using hazardous substances, dangerous pathogens, or emerging technologies. And according to the World Health Organization, every country needs to be prepared.
What Are Deliberate Events?
Deliberate events, as defined by WHO’s health topics framework, are intentional acts designed to harm people, animals, crops, or the environment using various means.
Traditionally, these events involved CBRN threats—chemical, biological, radiological, or nuclear materials. Think nerve agents like sarin or VX, biological pathogens like anthrax or smallpox, radioactive materials, or nuclear weapons.
But the threat landscape is evolving. Emerging threats now include disinformation campaigns that undermine public health responses, cyberattacks targeting hospital systems or medical supply chains, and misuse of new technologies like synthetic biology or artificial intelligence.
Dr. Maria Santos, who works in emergency preparedness at WHO, explained the shift: “We used to focus primarily on chemical and biological weapons—things you could see, detect, or measure. Now we’re dealing with threats that are invisible in different ways. A disinformation campaign during a pandemic can kill as many people as a biological weapon, just more slowly and harder to attribute.”
According to WHO’s fact sheet on deliberate events, these malicious acts can cause harm through multiple pathways: directly targeting humans or animals with harmful materials or pathogens, contaminating food or water supplies, destroying agricultural crops, or damaging environmental systems that support health.
The impacts can be immediate—like the Tokyo subway sarin attack in 1995 that killed 13 people and injured thousands. Or they can be delayed and diffuse—like disinformation about vaccines that gradually erodes immunization rates and triggers disease outbreaks.
The Blurred Line Between Health and Security
What makes deliberate events uniquely challenging is that they sit at the intersection of public health and national security.
When an outbreak of disease occurs naturally, health authorities lead the response. When someone deliberately releases a pathogen or toxin, both health and security sectors must coordinate.
The health sector’s role, as outlined in WHO’s preparedness guidelines, is to protect and manage the health and well-being of those at risk or affected. This means detecting the event quickly, treating victims, preventing spread, and maintaining essential health services.
The security sector and law enforcement’s role is to identify and control the source of the deliberate event, prevent the situation from worsening, and bring perpetrators to justice.
But these roles overlap messily in real events.
Dr. James Wilson, who responded to the 2001 anthrax attacks in the United States, described the tension: “We had public health officials trying to track disease spread while FBI agents were collecting evidence and treating everything as a crime scene. Hospital staff needed to treat patients while maintaining chain of custody for forensic samples. It required coordination we’d never really practiced.”
The global health-security interface that WHO helps strengthen addresses exactly this challenge—ensuring health and security authorities work together before, during, and after deliberate events.
For more context on emergency coordination, see our previous article on global health emergency response.
The Evolving Threat Landscape
Chemical Threats
Chemical weapons have a long and terrible history. From chlorine gas in World War I to nerve agents in Syria’s civil war, toxic chemicals deliberately released to harm populations represent one of the most feared threats.
WHO provides specialized training on chemical hazards preparedness through online courses covering identification, assessment, and immediate response actions.
Common chemical threats include nerve agents (sarin, VX, Novichok), blister agents (mustard gas), choking agents (chlorine, phosgene), blood agents (cyanide), and toxic industrial chemicals deliberately released.
The challenge with chemical events is speed. Symptoms can appear within minutes. Decontamination must happen quickly. Antidotes—when they exist—need administration immediately. Healthcare facilities must be prepared with protocols, equipment, and trained staff.
Biological Threats
Biological weapons use living organisms or toxins derived from them to cause disease and death. Historical examples include Japan’s Unit 731 experiments in World War II and the 2001 anthrax letters in the United States.
The threat has evolved with biotechnology. Advances in synthetic biology, gene editing, and pathogen engineering create new possibilities for deliberately engineered diseases. As WHO’s guidance on biological weapons emphasizes, the same technologies enabling medical breakthroughs can be misused for harm.
Biological events are particularly insidious because early stages may appear like natural disease outbreaks. Only careful epidemiological investigation reveals the deliberate nature—unusual disease patterns, unexpected pathogens, or genetic signatures indicating laboratory manipulation.
Radiological and Nuclear Threats
Radiological dispersal devices—so-called “dirty bombs”—combine conventional explosives with radioactive material. Nuclear weapons represent the most catastrophic deliberate event scenario.
WHO provides guidance on radiation emergencies and the health effects of ionizing radiation, including protective measures like potassium iodide distribution and management of contaminated populations.
Emerging Digital Threats
The newest category of deliberate events involves information and cyber domains.
Disinformation campaigns deliberately spread false health information to undermine public health responses, erode trust in authorities, reduce vaccination uptake, or promote dangerous behaviors. During COVID-19, disinformation about vaccines, treatments, and prevention measures directly contributed to preventable deaths.
Cyberattacks on health infrastructure target hospitals, supply chains, vaccine distribution systems, or health databases. Ransomware attacks that shut down hospital systems can kill patients when critical care is disrupted.
Dr. Lisa Chen, a cybersecurity specialist working with health systems, warned: “A sophisticated cyberattack that takes down hospital networks across multiple cities simultaneously could cause more casualties than a small-scale chemical attack. And it’s much harder to attribute and respond to.”
Preparedness: The Only Defense
Because deliberate events can happen anywhere at any time, preparedness is essential.
WHO advises Member States to take specific actions outlined in their emergency preparedness frameworks:
Assessment and Gap Identification
Countries need to evaluate their readiness using tools like the National Self-Assessment toolkit that measures national capacity to manage deliberate exposure to hazardous materials, disinformation, or cyberattacks.
This assessment typically feeds into Joint External Evaluations or National Action Plans for Health Security—frameworks for systematically building preparedness capacity.
Surveillance Systems
Early detection is critical. Public health surveillance systems must be sensitive enough to detect unusual disease patterns, unexpected chemical exposures, or anomalous health events that might indicate deliberate release.
The challenge is distinguishing deliberate events from natural outbreaks or accidents in real-time. Specific indicators—unusual disease clusters, unexpected age distributions, unusual pathogen characteristics, or multiple simultaneous outbreaks in different locations—can suggest deliberate acts.
Training and Capacity Building
WHO offers online training courses on chemical and biological deliberate events covering detection, response, and clinical management. These courses prepare healthcare workers, emergency responders, and public health officials to recognize and respond to deliberate events.
Simulation exercises test preparedness by creating realistic scenarios requiring coordinated health and security responses. These exercises identify gaps, improve coordination, and build muscle memory for crisis response.
Stockpiles and Equipment
Effective response requires deployable pharmaceuticals, supplies, and equipment. This includes personal protective equipment for healthcare workers, antidotes for chemical agents, antibiotics for biological threats, and decontamination equipment.
Many countries maintain strategic stockpiles, but as WHO emphasizes, stockpiles are only useful if personnel are trained to use them and distribution systems can deploy them rapidly.
International Cooperation
Deliberate events often require international assistance. Countries need protocols and formal agreements to request and receive help from WHO, neighboring countries, or international organizations.
For more on global health cooperation, see our article on international health emergency coordination.
WHO’s Response Role
When a deliberate event occurs, WHO can deploy experts at country, regional, and global levels to support response efforts upon request from affected countries.
Specific WHO response activities include:
Working with international and national laboratories to characterize the nature, scope, and impact of the event—identifying the agent used, determining exposure pathways, and assessing health consequences.
Providing targeted training to public health officials and frontline responders on managing specific threats.
Facilitating acquisition of necessary response materials like personal protective equipment, medical countermeasures, or specialized pharmaceuticals that affected countries may not have stockpiled.
Coordinating international expert support through networks including the Global Outbreak and Response Network (GOARN), WHO Collaborating Centres, and the UN Humanitarian Emergency Cluster system.
An important caveat: WHO does not investigate attribution—determining who perpetrated the attack. That remains the role of law enforcement and security agencies. WHO’s mandate is public health protection and response, not criminal investigation.
The Syria Experience: Lessons Learned
Syria’s civil war provided tragic lessons about deliberate chemical events in modern conflict.
WHO issued multiple statements expressing alarm about chemical attacks in Syria, including attacks using chlorine, sarin, and other toxic agents against civilian populations.
The health sector faced impossible challenges. Hospitals treating victims became targets themselves. Medical staff lacked protective equipment and antidotes. Documentation of evidence was complicated by security concerns and access restrictions.
International response was hindered by political divisions, attribution controversies, and the deliberate targeting of health facilities that violated international humanitarian law.
The Syria experience reinforced several critical lessons: health workers need protection when treating chemical attack victims, stockpiles of antidotes must be pre-positioned and accessible, decontamination capacity must exist at facility and community levels, and health and security coordination must function even in active conflict zones.
The Future of Deliberate Event Threats
The threat landscape continues evolving in concerning directions.
Synthetic biology and gene editing technologies could enable creation of novel pathogens with enhanced transmissibility or lethality. WHO’s biosecurity frameworks attempt to balance research freedom with security concerns.
Artificial intelligence could optimize attack planning, target selection, or disinformation campaigns. AI-generated deepfakes could spread false health information at unprecedented scale and believability.
Climate change and resource scarcity may increase motivations for deliberate events as desperate groups or states resort to unconventional weapons.
Globalization and interconnected systems mean a deliberate event in one location can rapidly affect distant populations—whether through direct exposure, supply chain disruptions, or cascading fear and social disruption.
Dr. Santos reflected on the challenge: “We’re trying to prepare for threats we can barely imagine using today’s technology. What worries me most isn’t the threats we know about—chemical weapons, anthrax, radiological devices. It’s the convergence of multiple technologies creating attack vectors we haven’t even conceived yet.”
What Must Happen
Addressing deliberate event threats requires sustained commitment across multiple domains.
Strengthen the Chemical Weapons Convention and Biological Weapons Convention to prevent proliferation of CBRN capabilities and establish robust verification mechanisms.
Invest in public health infrastructure that can detect and respond to both natural and deliberate events. The same surveillance and laboratory capacity needed for pandemic preparedness serves deliberate event response.
Build health-security coordination mechanisms before crises occur. Waiting until an event happens to establish communication channels and coordination protocols ensures confusion and delayed response.
Combat disinformation by building public trust in health institutions, improving science communication, and developing technological countermeasures to false information campaigns.
Secure health infrastructure against cyberattacks through investment in cybersecurity, backup systems, and resilient supply chains.
Maintain and update stockpiles of medical countermeasures, antidotes, and protective equipment while ensuring personnel are trained to deploy them effectively.
The International Health Regulations provide the legal framework for countries to build these capacities and coordinate international responses.
The Bottom Line
Deliberate events represent a unique challenge where public health meets national security, where medical response intersects with law enforcement, and where the weapons used can be as advanced as synthetic biology or as simple as disinformation spread through social media.
Every country faces these threats. None can address them alone.
Back to Salisbury and the Novichok attack: both victims survived after intensive care and international cooperation. The UK’s NHS activated protocols for chemical exposure. Russia’s use of a nerve agent on British soil triggered international diplomatic responses. WHO’s guidance on chemical weapons management informed medical care.
The attack demonstrated both the reality of deliberate chemical threats in modern times and the possibility of effective response when countries have prepared.
The question isn’t whether future deliberate events will occur. History and current geopolitics guarantee they will.
The question is whether countries will invest in the preparedness, coordination, and capacity needed to protect their populations when they do.
For more articles on global health security and emergency preparedness, visit ObserverVoice.com.
Frequently Asked Questions (FAQs)
Deliberate events are malicious acts with intentions to cause harm using hazardous materials, dangerous pathogens, or emerging technologies like cyber weapons or disinformation campaigns. Unlike natural disease outbreaks or accidents, deliberate events are intentional acts designed to harm people, animals, crops, or the environment. They can involve chemical, biological, radiological, or nuclear (CBRN) materials, or newer threats like cyberattacks on health infrastructure and disinformation undermining public health. The key difference is intent—these are attacks, not accidents or natural occurrences—which means they require coordinated health and security sector responses, not just public health measures. Learn more at WHO’s deliberate events information page.
Deliberate event threats include several categories. Chemical threats involve nerve agents (sarin, VX, Novichok), blister agents (mustard gas), choking agents (chlorine, phosgene), or toxic industrial chemicals deliberately released. Biological threats use pathogens like anthrax, smallpox, or engineered organisms to cause disease. Radiological threats involve radioactive materials dispersed through “dirty bombs” or nuclear weapons. Emerging threats include disinformation campaigns that spread false health information to undermine public health responses, and cyberattacks targeting hospitals, supply chains, or health databases. The threat landscape continues evolving with new technologies. For detailed information on specific threats, see WHO’s questions and answers on deliberate events.
Preparation involves multiple components coordinated across health and security sectors. Countries must assess their readiness using tools like the National Self-Assessment toolkit, strengthen public health surveillance systems to detect unusual patterns that might indicate deliberate events, train healthcare workers and emergency responders through programs like WHO’s online chemical and biological deliberate events courses, develop stockpiles of antidotes, protective equipment, and medical countermeasures, conduct simulation exercises to test response capabilities, and establish formal agreements for international assistance. The key is building capabilities before events occur, since rapid response is critical. WHO provides comprehensive guidance through its preparedness frameworks.
Upon request from affected countries, WHO deploys experts to support response efforts at country, regional, and global levels. WHO works with laboratories to identify the agents used and assess health impacts, provides targeted training to responders, facilitates acquisition of necessary medical countermeasures and protective equipment, and coordinates international expert support through networks like the Global Outbreak and Response Network (GOARN). However, WHO does not investigate attribution—determining who perpetrated the attack remains the responsibility of law enforcement and security agencies. WHO’s mandate focuses on public health protection and response. More details are available at WHO’s rapid response activities page.
Emerging digital threats pose serious and growing risks that can be as deadly as traditional chemical or biological weapons, though they operate differently. Disinformation campaigns during health emergencies can undermine vaccination programs, promote dangerous behaviors, and erode trust in health authorities—directly contributing to preventable deaths, as seen during COVID-19. Cyberattacks that disable hospital systems, disrupt medical supply chains, or compromise patient data can cause casualties when critical care is interrupted and may affect more people simultaneously than small-scale chemical or biological attacks. These threats are particularly challenging because they’re harder to attribute, can be launched from anywhere globally, and existing international frameworks weren’t designed to address them. WHO has developed specific guidance on disinformation and public health and cyberattacks on health infrastructure.
- WHO Deliberate Events Information Hub
- WHO Fact Sheet on Deliberate Events
- Chemical and Biological Deliberate Events Training Courses
- WHO Chemical Hazards Preparedness
- Public Health Response to Biological and Chemical Weapons
- Initial Clinical Management of Chemical Weapons Exposure
- Health-Security Interface Strengthening
Disclaimer: This article is an adaptation of publicly available information from WHO’s Deliberate events
health topic page (WHO, Geneva. Licence: CC BYNC-SA 3.0 IGO). WHO is not responsible for the
content or accuracy of this adaptation. This content is for informational and educational purposes
only and does not constitute medical advice. ObserverVoice.com is a news and information platform
— not a healthcare provider.
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