The Chernobyl nuclear meltdown in April 1986 was the most devastating nuclear catastrophe in history. Huge stretches of land were radioactively contaminated and made uninhabitable for generations. Nuclear fallout led to tens of thousands cases of cancer, malformations, still-births and deaths – not just in the former Soviet Union, but around the world.

History

The first nuclear reactor unit in Chernobyl was built between 1971 and 1977. By 1983, the plant had been expanded to include four reactor units. The neighboring city of Pripyat was home to 18,000 inhabitants, most of whom were employed directly or indirectly by the plant. The disaster began during a systems test on Saturday, April 26 in 1986. An emergency shutdown was attempted after a sudden power surge and a super-critical mass was reached, leading to a nuclear chain reaction. The reactor roof, weighing 1,000 tons, was lifted up by a giant explosion and the graphite on the fuel rods caught fire. A plume of highly radioactive smoke drifted over large parts of Eastern- and Central Europe and covered whole regions with radioactive fallout. Belarus, north of Chernobyl, received an especially large amount of fallout. Scandinavian countries, Asia Minor, and parts of Central Europe such as Bavaria registered radioactive iodine-131 and cesium-137. The nuclear meltdown was kept secret from the population for days, critically delaying evacuation efforts and protective measures.

Health and environmental effects

The immediate victims of the Chernobyl disaster were the roughly 800,000 people, mostly young red army recruits from across the Soviet Union, who were called in to control the effects of the meltdown – the “liquidators.” They had to carry radioactive debris across the accident site with their bare hands and construct a giant sarcophagus above the destroyed reactor. Approximately 15 % of them had already died by the year 2005, 19 years after the catastrophe; more than 90 % have developed diseases, many probably related to radiation exposure.

The explosions and fire spread radionuclides over large parts of Europe. Ingested or inhaled, these particles settle in living tissues, where they irradiate surrounding cells, causing cell damage, genetic mutations and, ultimately, cancer. Three radioisotopes are especially important. Iodine-131 is known to cause thyroid cancer, cesium-137 can cause solid tumors in basically all type of tissues and strontium-90 is a major cause of leukemia.² Chernobyl fallout affected not only the highly irradiated regions of the former USSR, but also parts of Northern, Central and Southeast Europe. As large-scale epidemiological research was never undertaken in the rest of Europe, one has to rely on calculations of morbidity and mortality based on collective dose estimations. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) estimated that the population of Europe was exposed to a collective effective dose of 400,000 Person-Sv and collective thyroid dose of 2,400,000 Person-Gy due to Chernobyl. Using internationally accepted risk factors, 21,000 people can be expected to develop thyroid cancer due to Chernobyl fallout and another 36,000 to 140,000 people would develop other types of cancer. A study published in the International Journal of Cancer also estimated 41,000 cases of cancer and more than 15,000 cancer deaths on account of Chernobyl.

While these numbers may seem small in comparison to the size of the affected population, it has to be recalled that each individual case represents a heavy burden not just to a single individual, but to a whole family. Also, these numbers most probably represent only a fraction of the true impact of the catastrophe, as the collective dose estimates and risk factors were subject to systemic underestimations. As with all man-made catastrophes, every single case is one too many. All over Europe, Chernobyl fallout also led to a rise in stillbirths, malformations, genetic disorders such as Down syndrome, autoimmune diseases such as diabetes and cardiovascular diseases. The psychological, environmental, economic and social effects of the catastrophe must also not be forgotten.

Outlook

In 1986, the ruptured reactor was covered by a temporary sarcophagus. The Ukrainian government has now ordered a new sarcophagus to be built in order to contain the estimated 180 tons of nuclear waste still left inside the reactor. The costs of this new structure add up to 1.5 billion US-dollars.

Because of genomic instabilities and transgenerational effects caused by radiation, the full extent of the disaster on people’s health may never be fully known. Chernobyl is more than just a singular event. It continues to kill – day by day, every year. The Soviet government, the nuclear industry and lobby groups such as the International Atomic Energy Agency (IAEA) have been able to obstruct critical publications in their attempt to close the file on Chernobyl. Cynically, they have declared the health problems of the liquidators were caused by stress and bad lifestyle. But the consequences of the Chernobyl catastrophe will continue to affect hundreds of thousands of families for many decades to come. They, too, are Hibakusha. The file on Chernobyl must not be closed.

Further reading

Read the thoroughly researched report “Health Effects of Chernobyl – 25 years after the reactor catastrophe” of the German IPPNW affiliate and the Society for Radiation Protection online at:
www.chernobylcongress.org/fileadmin/user_upload/pdfs/chernob_report_2011_en_web.pdf

References

• Cardis E et al. “Estimates of the cancer burden in Europe from radioactive fallout from the Chernobyl accident.” Int. J. Cancer: 119, 1224–1235 (2006). http://onlinelibrary.wiley.com/doi/10.1002/ijc.22037/pdf
• Pflugbeil S et al. “Health effects of Chernobyl – 25 years after the reactor catastrophe.” Society for Radiation Protection and IPPNW Germany, April 2011. http://www.chernobylcongress.org/fileadmin/user_upload/pdfs/chernob_report_2011_en_web.pdf
• “UNSCEAR 2013 Report; Volume I, Scientific Annex A.” UNSCEAR, April 2, 2014, p. 60. www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdf
• “BEIR VII Report, Phase 2: Health risks from exposure to low levels of ionizing radiation.” National Academies Press, Washington, 2006, p. 279F, tables 12.5a and 12.5b. www.nap.edu/openbook.php?record_id=11340&page=279