N° 168
20 April 2006 

The Cancer Burden from Chernobyl in Europe

Twenty years ago, the worst accident in the history of the nuclear industry occurred at the Chernobyl power plant in Ukraine. The full health impact of that accident is still difficult to assess directly1.

In June 2005, Dr Peter Boyle, Director of the International Agency for Research on Cancer (IARC), established an international Working Group to study the cancer consequences following the Chernobyl accident: its task was to evaluate the human cancer burden from radioactive fallout from the accident in Europe as a whole. The Working Group publishes its conclusions this week in the International Journal of Cancer in an article entitled: "Estimates of the Cancer Burden in Europe from Radioactive Fallout from the Chernobyl Accident.2

Dr Boyle said that: "Because the cancer burden from Chernobyl cannot at present be directly measured, the Working Group relied on risk prediction models developed from studies of other populations exposed to radiation in other settings, particularly the studies of the atomic bomb survivors in Japan."

Dr Boyle added that: "Based on these models, the number of cancer cases in Europe possibly resulting from radiation exposure from the Chernobyl accident in the lifetime of the exposed populations, is expected to be large in absolute terms." Dr Elisabeth Cardis, Head of the IARC Radiation Group, provided greater detail: "By 2065 (i.e. in the eighty years following the accident), predictions based on these models indicate that about 16,000 cases3 of thyroid cancer and 25,000 cases of other cancers may be expected due to radiation from the accident and that about 16,000 deaths from these cancers may occur."
Most of the cancer burden rests with the most exposed populations: "About two-thirds of the thyroid cancer cases and at least one half of the other cancers are expected to occur in Belarus, Ukraine and the most contaminated territories of the Russian Federation", she said. These are the three countries in proximity to the site of the accident.

But she added: "While these figures all reflect human suffering and death, they nevertheless represent only a very small fraction of the total number of cancers seen since the accident and expected in the future in Europe. Indeed, our analysis of the trends in cancer incidence and mortality does not demonstrate any increase that can be clearly attributed to the Chernobyl accident. The exception is thyroid cancer, which, over ten years ago, was already shown to be increased in the most contaminated regions around the site of the accident."

Dr Boyle concluded that "This study is unique in that it applies state-of-the-art radiation risk projection models to updated estimates of radiation dose from Chernobyl throughout Europe, and also includes a comprehensive examination of trends in cancer incidence and mortality data. It provides the best estimates to date of the impact of the Chernobyl accident on cancer in Europe. To put it in perspective, tobacco smoking will cause several thousand times more cancers in the same population".

1 Cardis E, Howe G, Ron E, Bebeshko VG, Bogdanova T, Bouville A, et al. Cancer Consequences Of The Chernobyl Accident: 20 Years After. J Radiol Prot. Vol 26: 2, pp 127-140. Online first from 24 April 2006: doi:10.1088/0952-4746/26/2/001.

2 Cardis E, Krewski D, Boniol M, Drozdovitch V, Darby SC, Gilbert ES, Akiba S, Benichou J, Ferlay J, Gandini S, Hill C, Howe G, Kesminiene A, Moser M, Sanchez M, Storm H, Voisin L & Boyle P. Estimates of the Cancer Burden in Europe from Radioactive Fallout from the Chernobyl Accident. Int J cancer. Early view 20/04/2006.

3 The figures presented here give only an order of magnitude of the possible number of radiation-related cancers. The uncertainty associated with these predictions is large. For thyroid cancers, the 95% uncertainty interval (UI) ranges from 3,400 to 72,000; for other cancers it ranges from 11,000 to 59,000. For the number of cancer deaths, the 95% UI ranges from 6,700 to 38,000 (see details in the Briefing Notes)

For more information, Contact:  .

World Health Organization
International Agency for Research on Cancer

Organisation mondiale de la Santé
Centre international de Recherche sur le Cancer

150, cours Albert-Thomas 69372 Lyon Cedex 08 (France)
Telephone: 33 472 738 485     Facsimile: 33 472 738 311