Back to News page
Thirty-nine years after Chornobyl – how is WHO helping Member States strengthen health security against chemical, biological and radio-nuclear threats?
On 26 April 1986, a safety test at reactor number 4 of the Chornobyl nuclear power plant in Ukraine went catastrophically wrong. The resulting explosion and fire released vast amounts of radioactive material into the atmosphere, triggering one of the worst nuclear disasters in history.
The consequences were profound – impacting human health, ecosystems and societies on a massive scale. While fewer than 50 immediate deaths were attributed directly to radiation exposure, primarily among first responders, thousands of others have suffered from potentially life-threatening radiation-related illness.
The radio-nuclear disaster in Chornobyl and events such as the 1976 dioxin-release accident in Seveso, Italy, or the 2018 Novichok poisonings in Salisbury, United Kingdom, clearly show that preparedness for chemical, biological, radiological and nuclear (CBRN) events is essential to safeguarding national health security.
But whether intentional or accidental, such events can also have devastating cross-border effects. Natural disasters, such as floods, may trigger chemical leaks that contaminate water supplies, while armed conflicts, like the ongoing war in Ukraine, increase the vulnerability of nuclear and chemical facilities – raising the risk of catastrophic releases.
Recognizing these threats, WHO and its partners are working with countries across the European Region to bolster their capacity to detect, respond to and mitigate CBRN risks.
This work is a key part of actions under Preparedness 2.0, the Region’s emergency preparedness and response strategy developed by Member States. Steps to strengthen CBRN preparedness are particularly urgent in Ukraine and surrounding countries, where the risk profile is elevated because of the war.
Building CBRN capabilities for stronger health systems
Traditionally the domain of military strategy, CBRN threat management is now an integral component of civilian public health and emergency preparedness. Health-care systems, in particular, are at the forefront of preparedness efforts.
“Most countries and most health systems have an emergency plan with an all-hazards approach, but there are complexities in a CBRN incident that are unique,” explains Graham Finnigan, Technical Officer for the Health Emergencies Programme at WHO/Europe.
“For example, access to personal protective equipment, access to specific medical countermeasures through antidotes, or just understanding the technique to decontaminate someone. There’s the care of vulnerable citizens as well. Because there are so many nuances around about how you manage a CBRN event, it’s important to be a bit more specific in terms of how you prepare, train and ensure your capability.”
Graham leads a key WHO initiative called CBRN in Action funded by the European Commission’s Directorate-General for Health and Food Safety (DG SANTE) through the EU4Health programme. The project supports Ukraine and neighbouring countries by enhancing their national and cross-border prevention and preparedness frameworks. It also strengthens crisis coordination, public health surveillance and early warning systems – key pillars of global health security.
Antonio Parenti, Director for Public Health, Cancer and Health Security, DG SANTE, confirms that the European Commission continues to support European Union (EU) Member States and neighbouring countries with regards to preparedness and response capacities for CBRN events through collaboration with WHO/Europe.
“Through the WHO/Europe collaboration, the Commission expects to improve the EU’s capacity to detect CBRN events by consolidating 3 main areas: identifying laboratories and testing systems; developing the concept of surveillance and reporting, in line with the EU early warning and response system (EWRS); and improving health authorities’ capacities to investigate outbreaks of unknown origin, through specialized training.”
Through hands-on training, simulation exercises and technical workshops, the CBRN in Action initiative is building the capacity of public health professionals to handle the complex realities of threats. It reinforces frontline medical preparedness and response systems – such as emergency medical teams, medical evacuation infrastructure and the readiness of hospitals to act as first-receivers – while fostering effective risk communication to help communities respond calmly and appropriately.
“The thing about CBRN is that it frightens lots of people,” says Graham. “But if you’re well-trained and well-equipped then you can respond quicker to CBRN incidents. If you have the right messages and the right systems in place, then you can minimize the effects.... It’s about how you manage it, how you respond to it and how you inform the public.”
Preparedness across the Region
Recent activities under the CBRN in Action project have directly supported health security improvements.
In March, a pilot programme in Poland enhanced the Hospital Safety Index, a tool for assessing hospitals' safety and vulnerabilities, with a new CBRN component. In Ukraine, addressing the potential risks associated with chemical, biological, radiological and nuclear threats is a vital part of the country’s national health security strategy; thus, in April, a hospital emergency workshop for medical staff from conflict-affected areas of the country was held to support hospitals to develop all-hazard emergency plans, tailored with a strong CBRN element to reflect local risk assessments. These plans will serve as templates for other health facilities across the country and national and regional authorities across the EU.
“WHO in Ukraine supports the strengthening of national capacities to respond swiftly and effectively to potential threats, while also fostering cross-sectoral cooperation among all actors involved in emergency response,” explained Dr Jarno Habicht, WHO Representative in Ukraine.
“This includes developing reliable detection systems, enhancing laboratory capacities for the rapid identification of CBRN threats, implementing effective emergency protocols, and training health-care professionals. Since 2022, WHO has trained more than 3400 health-care workers and first responders in managing chemical and radiological incidents and has equipped regional instructors with the skills to deploy and operate advanced tools,” Habicht added.
Honouring Chornobyl’s legacy by preparing for the future
As part of broader efforts to strengthen CBRN preparedness, the National Research Centre for Radiation Medicine, Haematology and Oncology of Ukraine – a WHO collaborating centre and member of the Radiation Emergency Medical Preparedness and Assistance Network (REMPAN) – has taken a leading role. Working with the WHO Country Office in Ukraine and WHO headquarters, the Centre has implemented a national education programme on radio-nuclear preparedness, training 425 professionals through 28 specialized courses between February 2023 and January 2025.
With support from the CBRN in Action project, the Centre has also upgraded its training capabilities by acquiring state-of-the-art radiation detection equipment. To mark the 39th anniversary of the Chornobyl disaster, the Centre hosted a high-level opening ceremony for its newly equipped training centre on 28 April 2025. Attendees included representatives from Ukraine’s Ministry of Health, the European Commission, national emergency medical services, Bogomolets National Medical University, Chornobyl-focused nongovernmental organizations and 3 high-risk, frontline oblasts (Zaporizhzhia, Khmelnitsky and Rivne).
CBRN preparedness bolsters health security
As the WHO European Region continues to face emerging risks – from war to climate-related disasters – investing in CBRN readiness is not just about crisis response. It is a proactive step toward stronger, more resilient health systems that can protect populations across borders, safeguard future generations and ensure that past mistakes are not repeated.