Chornobyl Disaster

Technogenic catastrophe

It has became 15 years now since Reactor Block 4 at Chornobyl exploded, sending deadly clouds of radioactivity sweeping over Europe and fueling international protests against the use of the atom to generate electricity.

It has led to the emission of about 300 mln Ci of radionuclides from the plant's active zone into the environment and resulted in radioactive contamination of 53.4 thousand sq.m of Ukrainian territory. 189 thousand Ha of arable land and 157 thousands Ha of forests have been withdrawn from active use due to high contamination levels. Direct losses alone, including the costs of main production assets and operation funds, as well as infrastructure facilities and natural resources that have been withdrawn from use, amount to approximately $ 10 billion.

The nature and the scope of the disaster have confronted Ukraine with the need to address new and extremely complicated issues. They include, among others, the assessment of the nature and levels of radioactive environmental contamination and its impact upon ecosystems and human health; population removal from the most strongly contaminated areas and providing them with lodging; providing health care for people affected by the disaster; ensuring stable condition of the "Shelter" (remains of the destroyed reactor), maintaining its safety and transforming it into an environmentally safe system; decontaminating contaminated areas and water sources; supplying safe food products to population, etc.

Territories of Ukraine were divided into four zones depending on levels of radionuclide contamination: Exclusion zone; zone of obligatory settling out; zone with the right for settling out; zone of residing with strict radiation control.

The Exclusion zone contains over 20 mln Ci of the accident emission radioactivity. This large accumulation of radionuclides in the zone causes the problem of radionuclides getting outside. Under high floods, the water reaches highly contaminated areas and washes out from the surface ground levels considerable amounts of radionuclides that are taken into the Dnieper. The Dnieper, complete with its water reservoirs, is the water supply source for about 30 mln residents of Ukraine, thus becoming a potential source of radiation doses for them.

Human catastrophe

Chornobyl is not just the technical disaster. It is a human catastrophe the effects of which are still being felt today. Even now, when the last operative reactor #3 is shut down, the Chornobyl legacy will not die away anytime soon.

The disaster has resulted in about 7% of the population of Ukraine, that is 3.361,870 people.

700 thousand children residing in the contaminated areas, since then removed and resettled, whose thyroid glands were subjected to iodine radiation, shall be the first medical priority.

The affected population falls into the following categories:

• liquidators who have been directly involved in the accident liquidation - 86,775 individuals;
• people resettled from contaminated areas, including adults, children and adolescents - 307,982 individuals;
• people still residing in strict radiation control areas - 549,649 individuals;
• children- 1,264,329 individuals.

The amount of affected population is expected to grow further due to the increase in the number of children acknowledged as affected because of receiving an increased thyroid gland irradiation dose and those born from liquidators and resettled parents.

Beyond the effects of radiation, there are the psychological and psychosomatic illnesses that are more difficult to quantity, illnesses precipitated by fear and uncertainty in the population at large.

Positive solution of the problem

Criteria that are supposed to indicate positive developments in solving the problem could be put as follows:

• Safety of the Exclusion zone per se and the facilities within it;
• Safety level of residing in the contaminated areas;
• Morbidity and mortality levels among affected population;
• Level of employment in relocated settlement and in contaminated areas;
• Level of psychosocial problems among the affected population;
• Level of social tension in the Chornobyl affected areas.

The National Operations Program for Minimizing the Chornobyl Disaster Aftermath defined specific indicators of the Programme implementation efficiency in health care and social protection areas: medical support and medical check-ups of the affected population; introducing new treatment and diagnostics methods for thyroid gland diseases, early diagnostics for blood diseases, nervous and mental dysfunctions, rehabilitation and assessing its efficiency, diagnostics for endocrines, immune and blood generating systems diseases; developing new medications with radio protective properties; expanding the data base on morbidity dynamics in affected population, etc.

The Operations Programme is also concerned with using scientifically valid countermeasures aimed at minimizing individual and collective human irradiation doses; developing guides regarding agricultural activities in contaminated areas; reducing radioactive contamination levels in agricultural land and retrieving it for economic use; manufacturing products for curative and preventive nutrition; setting up an alimentary protection system for individuals working in contaminated areas, etc.

Previous experiences and lessons learned

Within 15 years that passed since the Chornobyl catastrophe significant efforts have been undertaken to minimize its consequences both from the national side and by the international community.

The issue of mitigation of the Chornobyl impact upon the health condition of the citizens continues to be an urgent national issue. Considerable changes have been observed in the social and psychological conditions and aggravation of health conditions of persons (especially children) residing in the contaminated areas. The shift in the priorities of the issue, necessity to improve the situation of human rights in Ukraine, including new generations, call for a new Concept of population protection in connection with the Chornobyl accident. Currently the revised Concept is developed. It is based on: (a) new scientific data on the impact of ionizing radiation upon the human organism, disclosed in the publications of International Commission for Radio Protection, the Scientific Committee of UNO on the effects of atomic radiation, World Health Organization basic standards of radiological safety compiled by the International Agency for Atomic Power, in the principles of radiological protection; (b) experience and knowledge of Ukrainian and foreign experts, accumulated during the years of study and elimination of the Chornobyl impact in Ukraine, Russia, Belarus and other countries.

For many years to come coping with the consequences of the Chornobyl disaster will remain among the top priorities in Ukraine's Government policy, as required by Article 16 of the Constitution of Ukraine. The need to enhance the role and involvement of the international community in protecting people affected by the disaster was once again highlighted in the UN General Secretary's report to the 54th Session of the UN General Assembly in November 1999.