Ihor Hudkov: «Horizons of radiobiology and radioecology as a part of it are spanless»
It's been thirty years, since terms «radiation situation» and «radiation safety» were introduced into the Ukrainian language. However the state is paying less attention to radiobiology and radiology, as compared with the attention paid in the years after the Chernobyl disaster. Japan's experience has shown that this position is wrong. We are talking to Ihor Hudkov, the famous scientist and radiologist, head of Department of Radiobiology and Radiology of NUBiP, academician of NAAS of Ukraine, honored scientist of Ukraine, Soros professor about current trends in radiation science and the state of radioactive contamination in Ukraine.
— Ihor Mykolayovych, you are among the first to have taken part in the aftermath of the Chernobyl accident. It's been thirty years since that happened. And now, so to speak, in retrospect, let us remember the most memorable events.
I first got into the exclusion zone in July 1986 when by Council of Ministers of Ukraine I was appointed Chairman of interagency group on monitoring environmental radioactive contamination of the Dnieper River and the Black Sea Basin after the Chernobyl accident.
But apart from it, I liked radiobiology and while working at the Institute of Plant Physiology, where, by the way, I had worked for 23-years I got interested in radiation damage of plants. I was mostly struck by a huge number of morphological changes, in other words, the appearance of various abnormalities, defects in the plants in the forest near the nuclear power station, which later was called Red Forest. Back in 1973, in one of our books, written together with my teacher, professor D.M. Hrodzinsky we described and classified morphological changes that may occur in plants under the influence of ionizing radiation. Almost all of them and others could be seen in large numbers on trees of pine, spruce and others (pine is one of the most radiosensitive trees): removal of apical dominance, the emergence of dichotomies, cauliflower disease “witches’ broom”, a pathological change in the size of individual organs, the occurrence of tumours on the leaves, leaves changing colours and more. This is the appearance of a kind of freaks. If morphological changes reveal in the same amount in other organisms and humans (we all know that there was a large number of young people in exclusion zone our army was to eliminate the impact of the catastrophe). Fortunately, it did not happen.
I will not describe my other impressions as a scientist and a biologist. I can not forget a pathological secrecy associated with the catastrophe including research. We had no opportunity to publish data in public, we were allowed to discuss and consider them at the closed meetings. And it was at the time when international periodicals on radiobiology, ecology were overfilled with articles on the consequences of the accident. A radionuclide contamination of different power, which formed the boundary between contaminated and relatively pure areas was found in 17 Western European countries and in all of them researches were held openly. The ban in part (I emphasize, in part!) was lifted only in 1989.
In terms of the main task, we, the employees of seven departments and eight research organizations, had done it by October 1986. Thus we foresaw a possible radioactive contamination of water, especially drinking water, which further was justified. Five copies of the forecast was printed stamped "Top Secret". In open press, I saw in only in 20 years. In my library I have the sixth copy of this forecast.
On coming to work, better to say on my return to my alma mater in 1987 I was given the task to organize and to run the country's first department of radiobiology. The exclusive zone became a kind of laboratory where my colleagues and me have been researching since that time.
— As a leading scholar in radiobiology how can you assess the current state of radioactive contamination in Ukraine?
In 30 years, the radiation situation has certainly improved due to natural decay of radionuclides, the main of which is strontium-90 and cesium-137 with a half-life respectively 29 and 30 years. Thus, in the environment they became half (in 60 years it would be in less than 4 times, in 90 years – less than eight and so on by exhibitors). In addition, migration of radionuclides is processed, they are washed into the deeper layers of soil, are washed away into the lower Dnieper, are made from crop fields. And in many areas and agricultural lands pollution decreased by three, four or more times. Accordingly, plant and animal products which population consume have become cleaner.
But the majority of radiobiologists to whom I belong to are guided by the principle of radiobiology: there are no harmless doses of ionizing radiation. No matter how small the dose might be the slightest high energy nuclear particle is enough to trigger mutations in DNA. If this DNA is the one of a somatic cell it may cause cancer disease. If this is DNA of reproductive cells it might cause genetic disorders that will reveal themselves in the next generation.
— What, in your opinion, radiological pollution problems should be solved first at present?
According to the above said it is necessary to reduce a radiation dose using all possible means due to human activities that are done in agriculture, food industry, radiation hygiene. These means are designed, passed multiple tests and well known. We should not be satisfied when the present radionuclide contamination of our food in most cases corresponds to the so-called "DR-2006" - the permissible levels of radionuclides in food and water. We should remember that strontium-90 and cesium-137 are artificial radionuclides and they do not exist in nature. They appeared in the environment in 1945 after the first atomic bombs exploded and later after accidents at nuclear power stations thus forming an extra dose of biota, to which they have not adapted. Though I do believe that it is hardly possible to adjust to the exposure of ionizing radiation. Therefore, the formation of certain radio protective background in the body through the implementation of these measures, the consumption of food that has radiation blocking, radiation protecting, radiation corporating and radiation reproductive properties is the basis of living polluted areas. But it is a specific lifestyle. This is what I tell students at my lectures. It is a pity, but the number of faculties which include the discipline of radio biology into their curriculum is decreasing within years.
— And the last question. What are contemporary trends in radiobiology?
We must admit, the government is paying less and less attention to radiobiology, radioecology after the accident in Chernobyl. On the one hand, the government is not willing to look into the future , on the other it is the consequence of a negligent attitude to science, caused (so we want to believe) by a difficult economic situation.
On the contrary, the world is interested in this area of biology. It is proved by the growing desire of many countries to cooperate with Ukrainian scientists in this field. We can understand Japan, which is experiencing the consequences of the nuclear power plant "Fukushima-1", which occurred in 2011. But other countries such as the Netherlands, Norway, France, which did not suffer from such an accident do not cooperate with our university in this area.
Radiobiology can not be regarded as a science related to the atomic bomb and radiation accidents. It appeared 121 years ago. This fundamental science considers effects of ionizing radiation on Earth and on living organisms. The twentieth century has only added to this radiation, and the twenty-first century continues to add. So it is not necessary to talk about the lack of interest in radiobiology in the world.
In terms of the most promising tendencies in radiobiology we can say that these are the study of the impact of slight doses of ionising radiation on living organisms. Here we speak about doses which can impact the immune system negatively, cause genetic disorders and others. As well as about developing ways of protecting living organisms in long-term chronic exposure, identifying and the studying distant consequences of exposure such as a carcinogenic impact on life, regularities of genetic effects. It is important to study the characteristics and effects of incorporated (which involve cells and tissues of the body) radionuclides on the body, joint impact of ionizing radiation on the body and other factors (heavy metals, pesticides, temperature, etc.), radiation effects of the type “bystander effect”.
In general, I believe that the horizons of radiobiology and radioecology as a part of raiobiology which is becoming more and more independent are spanless.
Iryna Bilous
