On April 26, 1986 a major reactor accident occurred at the Chernobyl Nuclear Power Plant. This caused acute radiation injuries and deaths among plant workers and firemen. It also led to radiation exposure to thousands of persons involved in rescue and clean-up operations. There was severe radioactive contamination in the area, resulting in the evacuation of people from a 30-km zone around the power plant. It became clear over the months following the accident that radioactive contamination of varying severity had also occurred in extensive areas of Ukraine, Belarus and Russia up to hundreds of kilometers from the site.
Information about the severity and significance of this contamination was often sparse and uneven; public opinion was uncertain and even many doctors were not sure how to interpret information that did become available. As a result, there was a loss of confidence in the information and in the countermeasures recommended.
The Government of the USSR sought international assistance in tackling the problem. The World Health Organization (WHO) sent a team of experts in June 1989 as did the League of Red Cross and Red Crescent Societies, in early 1990.
The WHO concluded among other things that "scientists who are not well versed in radiation effects have attributed various biological and health effects to radiation exposure. These changes cannot be attributed to radiation exposure, especially when the normal incidence is unknown, and are much more likely to be due to psychological factors and stress. Attributing these effects to radiation not only increases the psychological pressure in the population and provokes additional stress-related health problems, it also undermines confidence in the competence of the radiation specialists". The League of Red Cross and Red Crescent Societies made similar observations.
In October 1989, the Government of the USSR formally requested the International Atomic Energy Agency (IAEA) to co-ordinate "an international experts' assessment of the concept which the USSR has evolved to enable the population to live safely in areas affected by radioactive contamination following the Chernobyl accident, and an evaluation of the effectiveness of the steps taken in these areas to safeguard the health of the population".
As a result, an international project was launched in the spring of 1990. An independent "International Advisory Committee" of 19 members was set up under the chairmanship of Dr. Itsuzo Shigematsu from Japan. Dr. Shigematsu is the Director of the Radiation Effects Research Foundation in Hiroshima, which, ever since 1950, has monitored and analysed the health situation of atomic bomb survivors in Japan, the largest population ever exposed to high doses of radiation. The other scientists on the Committee came from ten countries and five international organisations. The expertise encompassed, among other disciplines, medicine, radiopathology, radiation protection, nutrition, radioepidemiology and psychology.
The most active phase of the project ran from May 1990 until the end of that year. About 200 independent experts from 23 countries and 7 international organisations were involved, and 50 scientific missions visited the USSR. Laboratories in several countries, including Austria, France, and the USA, helped to analyse and evaluate collected material.
The goals of the project were to examine assessments of the radiological and health situation in areas of the USSR affected by the Chernobyl accident, and to evaluate measures to protect the population. The purpose of this brochure is to present a summary of the main results. The project was directed at the welfare of those people still living in contaminated areas. The radiation health effects for people already evacuated (from the 30-km zone) were not considered except for some of these people which have re-settled in the areas under review. Also excluded were the large numbers involved in emergency clean-up operations (called ''liquidators'') who were brought into the region temporarily. The health of these people, some of whom may have been exposed to high levels of radiation, reportedly is being monitored and also may be the object of future international work.
The international project, carried out in co-operation with local authorities, deliberately selected a number of settlements in the contaminated areas of concern to perform the necessary surveys. Some of the settlements were located in areas with relatively high soil surface contamination, while other settlements were chosen in areas of relatively low soil surface contamination, but with potential for high radiation doses to the people living there. Other settlements were selected outside the contaminated areas of concern for purposes of comparison.
The surveyed contaminated settlements were: Bragin Daleta Gden Gomel Khojniki Komrin Korchevka Korma Malozhin Michul'nya Mikulichi Milcha Narodichi Novoe Mesto Novozybkov Novye Babovichi Ovruch Polesskoe Rakitnoe Savenki Savichi Slovechno Staroe Vasil'kovo Starye Babovichi Svyatsk Veprin Zhatka Zlynka The surveyed settlements for comparison purposes were: Chemer Khodosy Kirovsk Krasilovka Surazh Trokovichi Unecha
The project received the full support of the USSR Government and the Governments of the Belarus, Russia and Ukraine. Assistance took various forms, including the participation of local scientists in cross-checking, extensive discussions with scientists involved in the project, and in the collection and preparation of field samples as well as medical examinations of the population, especially children, in the affected areas. There were open and frank conversations with authorities, scientists, and particularly local citizens that added to the international experts' understanding of the situation.
The numbers of examinations and other such activities reported later in this brochure give some idea of the extensive nature of the international effort deployed within the limits that were set for the project. The agreed method of operation was to concentrate on direct study of the environment and of the population in those more highly contaminated areas that were still inhabited (with suitable comparative studies in areas of low contamination). In parallel with these detailed independent sampling studies, a general evaluation was made of Soviet methodology and findings.
A short account of the risks of radiation and radioactivity can be found in the penultimate section of this brochure to help set in focus some of the presented information.