The International Atomic Energy Agency (IAEA) has provided support for a wide variety of technical activities related to radiation safety, environmental monitoring and protection, power plant management and safety, agricultural rehabilitation and nuclear waste management.
The World Health Organization (WHO) has supported a major effort, the International Programme on the Health Effects of the Chernobyl Accident, in collaboration with other international and national organizations, to provide humanitarian support and improved health care to the affected countries. A follow up programme is underway focused on thyroid disease, accident recovery workers, dose reconstruction and psycho-social effects.
The Food and Agriculture Organization (FAO), together with the IAEA, has contributed technology and expertise on agricultural counter-measures to reduce radioactive contamination and has helped in improving knowledge of the migration of radionuclides in soils, forests and water bodies to facilitate restoration of contaminated areas.
United Nations Educational, Scientific and Cultural Organization (UNESCO) has established nine social/psychological rehabilitation centres (locally known as "centres of trust") with support from the United Nations Children's Fund (UNICEF) and a variety of bilateral donors.
The United Nations Development Programme (UNDP) has been coordinating the aid activities related to Chernobyl within the three countries and assisting with improving environmental monitoring capacities.
The United Nations Department of Humanitarian Affairs (UNDHA) has played a coordination role in the UN Inter-Agency Task Force on Chernobyl, which ensures that all major donors are aware of assistance being provided and includes the European Commission.