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Keywords:

  • Chernobyl;
  • dose burden;
  • radionuclide decorporation

In many European countries levels of I-131, Cs-134/137, Sr-90, and other radionuclides in milk, dairy products, vegetables, grains, meat, and fish increased drastically (sometimes as much as 1,000-fold) immediately after the catastrophe. Up until 1991 the United States imported food products with measurable amounts of Chernobyl radioactive contamination, mostly from Turkey, Italy, Austria, West Germany, Greece, Yugoslavia, Hungary, Sweden, and Denmark. These products included juices, cheeses, pasta, mushrooms, hazelnuts, sage, figs, tea, thyme, juniper, caraway seeds, and apricots. In Gomel, Mogilev, and Brest provinces in Belarus 7–8% of milk and 13–16% of other food products from small farms exceeded permissible levels of Cs-137, even as recently as 2005–2007. As of 2000, up to 90% of the wild berries and mushrooms exceeded permissible levels of Cs-137 in Rovno and Zhytomir provinces, Ukraine. Owing to weight and metabolic differences, a child's radiation exposure is 3–5 times higher than that of an adult on the same diet. From 1995 to 2007, up to 90% of the children from heavily contaminated territories of Belarus had levels of Cs-137 accumulation higher than 15–20 Bq/kg, with maximum levels of up to 7,300 Bq/kg in Narovlya District, Gomel Province. Average levels of incorporated Cs-137 and Sr-90 in the heavily contaminated territories of Belarus, Ukraine, and European Russia did not decline, but rather increased from 1991 to 2005. Given that more than 90% of the current radiation fallout is due to Cs-137, with a half-life of about 30 years, we know that the contaminated areas will be dangerously radioactive for roughly the next three centuries.

Tens of thousands of Chernobyl children (mostly from Belarus) annually leave to receive treatment and health care in other countries. Doctors from many countries gratuitously work in the Chernobyl contaminated territories, helping to minimize the consequences of this most terrible technologic catastrophe in history. But the scale and spectrum of the consequences are so high, that no country in the world can cope alone with the long-term consequences of such a catastrophe as Chernobyl. The countries that have suffered the most, especially Ukraine and Belarus, extend gratitude for the help that has come through the United Nations and other international organizations, as well as from private funds and initiatives. Twenty-two years after the Chernobyl releases, the annual individual dose limit in heavily contaminated territories of Belarus, Ukraine, and European Russia exceed 1 mSv/year just because of the unavoidable consumption of locally contaminated products. The 11-year experience of the BELRAD Institute shows that for effective radiation protection it is necessary to establish the interference level for children at 30% of the official dangerous limit (i.e., 15–20 Bq/kg). The direct whole body counting measurements of Cs-137 accumulation in the bodies of inhabitants of the heavily contaminated Belarussian region shows that the official Dose Catalogue underestimates the annual dose burdens by three to eight times. For practical reasons the curative-like use of apple-pectin food additives might be especially helpful for effective decorporation of Cs-137. From 1996 to 2007 a total of more than 160,000 Belarussian children received pectin food additives during 18 to 25 days of treatment (5 g twice a day). As a result, levels of Cs-137 in children's organs decreased after each course of pectin additives by an average of 30 to 40%. Manufacture and application of various pectin-based food additives and drinks (using apples, currants, grapes, sea seaweed, etc.) is one of the most effective ways for individual radioprotection (through decorporation) under circumstances where consumption of radioactively contaminated food is unavoidable.

Owing to internally absorbed radionuclides, radiation levels for individuals living in the contaminated territories of Belarus, Ukraine, and Russia have been increasing steadily since 1994. Special protective measures in connection with agriculture, forestry, hunting, and fishing are necessary to protect the health of people in all the radioactively contaminated territories. Among the measures that have proven to be effective in reducing levels of incorporated radionuclides in meat production are food additives with ferrocyanides, zeolites, and mineral salts. Significant decreases in radionuclide levels in crops are achieved using lime/Ca as an antagonist of Sr-90, K fertilizers as antagonists of Cs-137, and phosphoric fertilizers that form a hard, soluble phosphate with Sr-90. Disk tillage and replowing of hayfields incorporating applications of organic and mineral fertilizers reduces the levels of Cs-137 and Sr-90 three- to fivefold in herbage grown in mineral soils. Among food technologies to reduce radionuclide content are cleaning cereal seeds, processing potatoes into starch, processing carbohydrate-containing products into sugars, and processing milk into cream and butter. There are several simple cooking techniques that decrease radionuclides in foodstuffs. Belarus has effectively used some forestry operations to create “a live partition wall,” to regulate the redistribution of radionuclides into ecosystems. All such protective measures will be necessary in many European territories for many generations.

More than 50% of Chernobyl's radionuclides were dispersed outside of Belarus, Ukraine, and European Russia and caused fallout as far away as North America. In 1986 nearly 400 million people lived in areas radioactively contaminated at a level higher than 4 kBq/m2 and nearly 5 million individuals are still being exposed to dangerous contamination. The increase in morbidity, premature aging, and mutations is seen in all the contaminated territories that have been studied. The increase in the rates of total mortality for the first 17 years in European Russia was up to 3.75% and in Ukraine it was up to 4.0%. Levels of internal irradiation are increasing owing to plants absorbing and recycling Cs-137, Sr-90, Pu, and Am. During recent years, where internal levels of Cs-137 have exceeded 1 mSv/year, which is considered “safe,” it must be lowered to 50 Bq/kg in children and to 75 Bq/kg in adults. Useful practices to accomplish this include applying mineral fertilizers on agricultural lands, K and organosoluble lignin on forestlands, and regular individual consumption of natural pectin enterosorbents. Extensive international help is needed to provide radiation protection for children, especially in Belarus, where over the next 25 to 30 years radionuclides will continue to contaminate plants through the root layers in the soil. Irradiated populations of plants and animals exhibit a variety of morphological deformities and have significantly higher levels of mutations that were rare prior to 1986. The Chernobyl zone is a “black hole”: some species may persist there only via immigration from uncontaminated areas.