The Chernobyl accident occurred in April 1986 in Ukraine. It resulted in the most severe exposure of a human population to ionizing radiation apart from the 1945 atomic bombings in Japan. Although several reviews of the accident′s health consequences have been conducted, there remains disagreement over both the consequences to date and those expected in the future.

In 2008-2010, an international group of experts and advisors, led by the International Agency for Research on Cancer, carried out the European Union-funded Agenda for Research on Chernobyl Health (ARCH) project. One of the project′s conclusions was that well-designed and coordinated long-term studies of the health effects of the accident are needed because radiation-related diseases can occur decades after exposure.

Chernobyl has an iconic status in the public consciousness, and comprehensive studies of the accident′s health effects are of great importance to adequately inform the exposed population by providing concrete (rather than speculative) estimates of the consequences. Investigating the effects of Chernobyl not only provides the opportunity to answer questions about radiation risks to the general population but also to conduct the types of authoritative studies needed to test novel hypotheses about radiation effects and biology/genetics in general.

The Cooperation on Chernobyl Health Research (CO-CHER) project is a further step towards the implementation of the ARCH strategic research agenda (SRA). The project′s purpose was to bring together key scientific players to define research priorities and to obtain seed funding.

Based on the further prioritised research needs in epidemiology, clinical medicine, mental health, dosimetry, molecular biology, pathology and risk communication, Chernobyl Research Programme (CRP) was developed. The CRP was approved by the partners and experts who participated in the international symposium held at IARC, Lyon on 11 June 2016 to mark the 30th anniversary of the Chernobyl accident. CO-CHER recommends a continuation of the project by convening a multinational body (Chernobyl Research Committee) to facilitate international collaborations and research.

The project was funded by the European Commission Euratom FP7 grant No. 605302.