On 26 April 1986, following a routine 20-second system shut down in Chernobyl Nuclear Power Plant, a surge created a chemical explosion. The accident and the fire that followed released massive amounts of radioactive material into the environment over large parts of the Soviet Union, now the territories of Belarus, Ukraine and the Russian Federation, exposing million of people to radiations. In 2016, the United Nations General Assembly adopted a resolution designating 26 April as International Chernobyl Disaster Remembrance Day.


The explosion at the Chernobyl Nuclear Power Plant in April 1986 spread a radioactive cloud over large parts of the Soviet Union, now the territories of Belarus, Ukraine and the Russian Federation. Nearly 8.4 million people in the three countries were exposed to radiation.

The Soviet Government acknowledged the need for international assistance in 1990. That same year the General Assembly adopted resolution 45/190, calling for “international cooperation to address and mitigate the consequences at the Chernobyl nuclear power plant.” That was the start of the United Nations’ involvement in the Chernobyl recovery. An Inter-Agency Task Force was established to coordinate the Chernobyl cooperation. In 1991 the UN created the Chernobyl Trust Fund – currently under the management of the Office for the Coordination of Humanitarian Affairs (OCHA). Since 1986, the UN family of organizations and major NGOs have launched more than 230 different research and assistance projects in the fields of health, nuclear safety, rehabilitation, environment, production of clean foods and information.

On 8 December 2016, the United Nations General Assembly adopted a resolution designating 26 April as International Chernobyl Disaster Remembrance Day. In its resolution, the General Assembly recognized that three decades after the disaster there remain persistent serious long-term consequences and that the affected communities and territories are experiencing continuing related needs. The General Assembly invites all Member States, relevant agencies of the United Nations system and other international organizations, as well as civil society, to observe the day.



Chernobyl Nuclear Power Plant, 26 April 1986 – A routine 20-second shut down of the system seemed to be another test of the electrical equipment. But seven seconds later, a surge created a chemical explosion that released nearly 520 dangerous radionuclides into the atmosphere. The force of the explosion spread contamination over large parts of the Soviet Union, now the territories of Belarus, Ukraine and Russia. According to official reports, thirty-one people died immediately and 600,000 “liquidators,” involved in fire-fighting and clean-up operations, were exposed to high doses of radiation. Based on the official reports, nearly 8,400,000 people in Belarus, Russia and Ukraine were exposed to radiation, which is more than the population of Austria. About 155,000 sq. km of territories in the three countries were contaminated, almost half of the total territory of Italy. Agricultural areas covering nearly 52,000 sq. km, which is more than the size of Denmark, were contaminated with cesium-137 and strontium-90, with 30-year and 28-year half-lives respectively. Nearly 404,000 people were resettled, but millions continued to live in an environment where continued residual exposure created a range of adverse effects.


No reports were released until the third day after the Chernobyl explosion. Then, Swedish authorities correlated a map of enhanced radiation levels in Europe with wind direction and announced to the world that a nuclear accident had occurred somewhere in the Soviet Union. Before Sweden’s announcement, the Soviet authorities were conducting emergency fire-fighting and clean-up operations but had chosen not to report the accident or its scale in full. No established legitimate authority was able to immediately address the situation and provide answers to questions such as: Is it safe to leave the house? Is it safe to drink water? Is it safe to eat local produce? Communicating protective measures early would also have most likely enabled the population to escape exposure to some radionuclides, such as iodine 131, which are known to cause thyroid cancer. Early evacuation would have helped people avoid the area during the period when iodine 131 is most dangerous, 8-16 days after release.

The Elephant’s Foot is the nickname given to a large mass of corium formed underneath the Chernobyl Nuclear Power Plant. It is still an extremely radioactive object. Photo by: Artur Korneyev, 1996

During the first four years after the Chernobyl accident, the Soviet authorities decided to largely deal with the consequences of the explosion at a national level. Without Soviet endorsement, the United Nations and its partners sought ways to provide emergency support, which included assessing the nuclear safety and environmental conditions of the contaminated area, and diagnosing the various medical conditions that resulted from the accident. The UN also focused on raising the awareness of the area’s inhabitants, teaching them how to protect themselves from radionuclides found in the environment and in agricultural products.

Involvement of the United Nations

Many count the year 1990 as a crucial point in the United Nations’ involvement in the Chernobyl recovery. The Soviet Government acknowledged the need for international assistance. As a result, the General Assembly adopted Resolution 45/190, which called for “international cooperation to address and mitigate the consequences at the Chernobyl nuclear power plant”. This Resolution also entrusted one of the Under-Secretary-Generals with the task of coordinating the Chernobyl co-operation and called for the formation of an Inter-Agency Task Force. The Quadripartite Coordination Committee, which consists of ministers from Belarus, Russia and Ukraine, as well as the United Nations Chernobyl Coordinator, became part of the coordination mechanism at the ministerial level. In 1992, a year after the Task Force was established, the Department of Humanitarian Affairs, which came to be called the Office for the Coordination of Humanitarian Affairs (OCHA) in 1997, began to coordinate international co-operation on Chernobyl. To expedite financial contributions towards the Chernobyl activities, the Chernobyl Trust Fund was established in 1991 under the management of OCHA. OCHA began to manage a range of diverse tasks and responsibilities from strategy formulation and promotion to resources mobilization, advocacy and channelling donors’ contributions. Since 1986, United Nations organizations and major Non-Governmental Organizations and Foundations have launched more than 230 different research and assistance projects in the fields of health, nuclear safety, including the construction of the Shelter, socio-psychological rehabilitation, economic rehabilitation, the environment, production of clean foods, and provision of information.

Over time it has become clear that the task of environmental and health recovery cannot be separated from the task of development. In 2001, UNDP, and its regional director for the three affected countries, became part of the coordination mechanism for Chernobyl cooperation. In the following year, the United Nations announced a shift in strategy, with a new focus on a long-term developmental approach, as opposed to emergency humanitarian assistance. In 2004, the UN Secretary-General transferred the coordination responsibility from UN OCHA to UNDP as part of a shift in strategy based on the 2002 study “The Human Consequences of the Chernobyl Nuclear Accident: A Strategy for Recovery“. In the course of assuming coordination responsibilities, UNDP has identified three priority areas to pursue on Chernobyl:

  • Information provision, including on promotion of healthy lifestyles;
  • Community-based social and economic development;
  • Policy advice, aimed at helping governments rationalize Chernobyl spending.

The United Nations has helped to address the needs of people in the areas surrounding Chernobyl, first through emergency and humanitarian aid, and then by supporting recovery and social and economic development, through our United Nations country teams working with civil society, international partners and donors. The Chernobyl disaster was contained by governments working with academics, civil society and others, for the common good. It holds important lessons for today’s efforts to respond to other crises.

Disaster knows no borders. But together, we can work to prevent and contain them, support all those in need, and build a strong recovery.

Antonio Guterres, Secretary-General

Nuclear Impacts

Since the early development of nuclear technology, it has been highly controversial, with among the key concerns the ecological impacts of nuclear accidents and radioactive waste disposal.


Isotopes released during a meltdown or related event are typically dispersed into the atmosphere and then settle to the surface through natural occurrences and deposition. Isotopes settling in the topsoil layer can remain there for many years as a result of the half-life of said particles involved in nuclear events. Due to the long term detrimental effects on agriculture, farming and livestock, it carries further potential to affect human health and safety long after the actual event. In Chernobyl, the amount of focused radiation caused severe damage to plant reproduction, resulting in most plants being unable to reproduce for a minimum of three years. Many of these occurrences on land can be a result of the distribution of isotopes through water systems.


Due to the violent nature of the accident in Chernobyl, a sizable portion of radioactive contamination was dispersed through the atmosphere. Many of these contaminants settled in groundwater systems in the immediate surrounding areas, but also in Russia and Belarus. Due to the resulting radiation in groundwater, the ecological effects of the disaster can be seen in various aspects down the environmental process line. Radionuclides carried by groundwater systems in and around the areas of Chernobyl have resulted in the uptake to plants in the region and up the food chains into animals, and eventually, humans – as one of the largest exposure points of radiation was through agriculture contaminated by radioactive groundwater. Again, one of the largest concerns to the local populaces within the 30 km exclusion zone is the intake of Cs-137 through the consumption of agricultural products contaminated with groundwater. Comparatively, thanks to the environmental and soil conditions outside the exclusion zone, the recorded levels are below those that require remediation based on a survey in 1996. During this event, the groundwater transportation of radioactive material carried over borders into neighbouring countries. Belarus, lying to Chernobyl’s northern border, was subject to approximately 250,000 hectares of previously usable farmland being held by state officials until deemed safe.

Off-site radiological risk may be found in the form of flooding. Many citizens in the surrounding areas have been deemed at risk of exposure to radiation due to the Chernobyl Reactor’s proximity to floodplains. A study conducted in 1996 was conducted to see how far the radioactive effects were felt across eastern Europe. Lake Kojanovskoe in Russia, 250 km from the Chernobyl accident site, was found to be one of the most impacted lakes traced from the disaster area. Fish collected from the lake were found to be 60 times more radioactive than the European Union Standard. Further investigation found that the water source feeding the lake provided drinking water for approximately 9 million Ukrainians, as well as provided agricultural irrigation and food for 23 million more.

A cover was constructed around the damaged reactor of the Chernobyl nuclear plant. This helps in the remediation of leaking radioactive material from the site of the accident but does little to help aid the local area with isotopes that were dispersed in its soils and waterways more than 30 years ago. Partially due to the already abandoned urban areas, as well as international relations currently affecting the country, remediation efforts have been minimized compared to the initial clean up actions and more recent accidents such as the Fukushima incident.


Evacuation and relocation proved a deeply traumatic experience for many people with profound psychosocial impact due to the loss of homes and jobs, rupture of the social fabric of communities and a social stigma associated with Chernobyl. WHO, along with the scientific research agencies and the governments of the three affected states, has been leading the efforts to assess and mitigate the health consequences of the accident by limiting the exposure of the population, supporting medical follow-up to those affected and harnessing the scientific cooperation to study the health impact of the incident.

Current Situation

This day of remembrance takes on a renewed importance as recent events in the region unfold. The International Atomic Energy Agency (IAEA) expressed concerns about the dangers of the conflict in the area. On 26 April, IAEA Director General, Rafael Mariano Grossi, headed an expert mission to Ukraine’s Chornobyl Nuclear Power Plant to step up efforts to help prevent the danger of a nuclear accident during the current conflict in the country. The IAEA provides daily updates on the situation in Ukraine. More information is provided in the resources below:

Role of Geneva

Geneva is an international hub on nuclear research, human rights, labour, migration, as well as health and environmental issues. The organizations working on issues related to the Chernobyl Disaster and nuclear impacts are presented below in alphabetical order.

Amnesty International

Amnesty International is a global movement campaigning for a world where human rights are enjoyed by all. Among its many streams of work, Amnesty works on the environmental consequences of conflict, localized violent environmental conflicts, and environmental disasters.

Conference on Disarmament (CD)

The Conference on Disarmament (CD), established in 1979, is the single multilateral disarmament negotiating forum of the international community, following the first Special Session on Disarmament (SSOD I) of the United Nations General Assembly held in 1978. The Director-General of the United Nations Office in Geneva (UNOG) is the Secretary-General of the Conference on Disarmament as well as the Personal Representative of the UN Secretary-General to the CD.

The terms of reference of the CD include practically all multilateral arms control and disarmament problems. Currently, the CD focuses on the following issues:

  • Cessation of the nuclear arms race and nuclear disarmament
  • Prevention of nuclear war, including all related matters
  • Prevention of an arms race in outer space
  • Effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons
  • New types of weapons of mass destruction and new systems of such weapons including radiological weapons
  • Comprehensive programme of disarmament and transparency in armaments
  • Verification of nuclear disarmament

The CD and its predecessors have negotiated major multilateral arms limitation and disarmament agreements such as:

  • Treaty on the Non-Proliferation of Nuclear Weapons
  • Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques
  • Treaty on the Prohibition of the Emplacement of Nuclear Weapons and Other Weapons of Mass Destruction on the Sea-Bed and the Ocean Floor and in the Subsoil thereof
  • Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on their Destruction
  • Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction and Comprehensive Nuclear-Test-Ban Treaty

Convention on the Protection and Use of Transboundary Watercourses and International Lakes (Water Convention)

The Water Convention, administrated by UNECE, strengthens transboundary water cooperation and measures for the ecologically-sound management and protection of transboundary surface waters and groundwaters. The Convention fosters the implementation of integrated water resources management, in particular the basin approach. The Convention’s implementation contributes to the achievement of the Sustainable Development Goals (SDGs) and other international commitments on water, environment and sustainable development.

The Protocol on Water and Health, jointly serviced by UNECE and WHO-Europe , is a unique legally-binding instrument aiming to protect human health through better water management and by reducing water-related diseases.

Convention on the Transboundary Effects of Industrial Accidents

The Convention on the Transboundary Effects of Industrial Accidents administered by UNECE helps Parties to prevent industrial accidents that can have transboundary effects and to prepare for, and respond to, accidents if they occur. It aims at protecting human beings and the environment against industrial accidents by preventing such accidents as far as possible, reducing their frequency and severity and by mitigating their effects. It promotes active international cooperation between the contracting Parties, before, during and after an industrial accident. This Convention is part of a pan-European legal framework to protect the environment and encourage sustainable development that has been negotiated by governments within the UNECE in response to regional challenges. Apart from this Convention, the framework also consists of four other multilateral agreements:

The Convention also encourages its Parties to help each other in the event of such an accident, to cooperate on research and development, and to share information and technology.

European Organization for Nuclear Research

The European Organization for Nuclear Research, known as CERN, is a European research organization that operates the largest particle physics laboratory in the world. Established in 1954, CERN’s main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research. As a result, numerous experiments have been constructed at CERN through international collaborations.

The main site at Meyrin in Geneva hosts a large computing facility, which is primarily used to store and analyze data from experiments, as well as simulate events. Researchers need remote access to these facilities, so the lab has historically been a major wide area network hub. CERN is also the birthplace of the World Wide Web.

Geneva Centre for Security Policy (GCSP)

The GCSP is an international foundation with the mission to advance peace, security and international cooperation. Their work focuses on the complex inter-linkages amongst various human security challenges with a special focus on health and environmental security. As a centre of expertise, the GCSP offers various courses on environment and security.

Geneva Water Hub

The Geneva Water Hub is a centre of excellence specialized in hydropolitics and hydrodiplomacy of the University of Geneva. Its goal is to better understand and prevent water-related tensions between competing uses, between public and private actors, and between political entities and countries.

Global Alliance on Health and Pollution (GAHP)

The GAHP is a collaborative body made up of more than 60 members and dozens of observers that advocates for resources and solutions to pollution problems. GAHP was formed because international and national level actors/ agencies recognize that a collaborative, multi-stakeholder, multi-sectoral approach is necessary and critical to deal with the global pollution crisis and resulting health and economic impacts.

International Committee of the Red Cross (ICRC)

The ICRC is an independent, neutral organization ensuring humanitarian protection and assistance for victims of war and armed violence. As an essential part of protecting civilians and their livelihood, the ICRC is supporting the implementation of practical measures to protect the natural environment in times of conflict.

International Campaign to Abolish Nuclear Weapons (ICAN)

Also based in Geneva is the International Campaign to Abolish Nuclear Weapons (ICAN), a coalition of non-governmental organizations in 100 countries promoting adherence to and implementation of the United Nations nuclear weapon ban treaty. This landmark global agreement was adopted in New York on 7 July 2017. ICAN also won the Nobel Peace Prize in 2017.

International Labour Organization (ILO)

The ILO is devoted to promoting social justice and internationally recognized human and labour rights, pursuing its founding mission that social justice is essential to universal and lasting peace. The only tripartite United Nations agency, since 1919 the ILO brings together governments, employers and workers of 187 member States, to set labour standards, develop policies and devise programmes promoting decent work for all women and men. It also accounts for the protection of workers from exposure to hazardous substances are among the topics addressed by ILO. There are 14 ILO Conventions and Recommendations in the field of Chemical Safety.

International Organization for Migration (IOM)

The IOM is dedicated to promoting humane and orderly migration for the benefit of all. It does so by providing services and advice to governments and migrants. It also works to help ensure the orderly and humane management of migration, promote international cooperation on migration issues, assist in the search for practical solutions to migration problems and provide humanitarian assistance to migrants in need, including refugees and internally displaced people.

United Nations Office for Disaster Risk Reduction (UNDRR)

UNDRR (formerly UNISDR) is the United Nations focal point for disaster risk reduction. UNDRR oversees the implementation of the Sendai Framework for Disaster Risk Reduction 2015-2030, supporting countries in its implementation, monitoring and sharing what works in reducing existing risk and preventing the creation of new risk.

United Nations Economic Commission for Europe (UNECE)

The United Nations Economic Commission for Europe, UNECE, through its Committee on Environmental Policy, works to support countries to enhance their environmental governance and transboundary cooperation. Its main aim is to assess countries’ efforts to reduce their overall pollution burden and manage their natural resources, integrate environmental and socioeconomic policies, strengthen cooperation with the international community, harmonize environmental conditions and policies throughout the region and stimulate greater involvement of the public and environmental discussions and decision-making. UNECE also hosts several other conventions and protocols, some of which are listed above.

United Nations Environment Programme (UNEP) – Europe Office

The UNEP Europe Office provides guidance to national governments at various levels and takes part in the dialogue on environmental issues between governmental authorities, civil society, the private sector and other stakeholders. This includes projects to strengthen ecosystem management, for the benefit of people and biodiversity.

World Food Programme (WFP) Office in Geneva

WFP work on sustainable livelihoods and ecosystems helps countries and the most vulnerable and food-insecure communities manage natural resources sustainably such as soil conservation and fertility measures; water harvesting and flood control; agro-ecological productivity to reduce biodiversity loss; irrigation schemes; forestry and agroforestry management; and, access to clean water in arid and semi-arid contexts results in more diversified food, thereby complementing nutrition efforts.  The restoration of degraded ecosystems boosts public health and reduces hardship in general.

United Nations Special Rapporteur on the Right to Health

The Special Rapporteur on Human Rights and the Environment is mandated to continue to study the human rights obligation towards the full realization of the right of all to the enjoyment of the highest attainable standard of physical and mental health. The current Special Rapporteur is Tlaleng Mofokeng.

United Nations Special Rapporteur on Human Rights and the Environment

The Special Rapporteur on Human Rights and the Environment is mandated to continue to study the human rights obligations relating to the enjoyment of a safe, clean, healthy and sustainable environment. The current Special Rapporteur, David R. Boyd, has developed various reports, such  “The right to a clean, healthy and sustainable environment: non-toxic environment“, that highlight the interlinkages between a healthy environment and well-being.

World Health Organization (WHO)

The WHO, along with the scientific research agencies and the governments of the three affected states, has been leading the efforts to assess and mitigate the health consequences of the Chernobyl Disaster by limiting the exposure of the population, supporting medical follow-up for those affected and harnessing the scientific cooperation to study the health impact of the incident.

The 2006 WHO report Health Effects of the Chernobyl Accidents and Special Health Care Programmes was developed as a result of the UN inter-agency initiative “Chernobyl Forum” implemented in 2003-2005 with the participation of the European Commission, International Atomic Energy Agency, UN Development Programme, World Bank and the governments of the three most affected countries – Belarus, Ukraine, and the Russian Federation.

Past events



General Documents

Special commemorative meetings

Environment, armed conflict and nuclear weapons