25th Anniversary of Chernobyl Nuclear Accident is Next Week

The 25th anniversary of the Chernobyl nuclear accident is next Tuesday, April 26. Experts in the Global Security Program at the Union of Concerned Scientists (UCS) recently revisited one of the nagging questions about Chernobyl’s health impact. They estimate that the number of excess cancer deaths -- deaths that would not have occurred under normal circumstances – attributable to the radiation released by the accident will be approximately 25,000. That conclusion is more than six times higher than a frequently cited figure from the U.N.-sponsored Chernobyl Forum, which estimated 4,000 excess cancer deaths. The UCS analysis, released earlier this week, also estimates there will be some 50,000 excess cancers due to the accident.

Both UCS estimates exclude thyroid cancers. The U.N. Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has estimated the incidence of thyroid cancers from Chernobyl. It found that, as of 2005, some 6,000 thyroid cancers and 15 thyroid cancer deaths are attributable to the accident. That number will grow over time, although the number of deaths is expected to be low because thyroid cancer is readily curable.

Why was the Chernobyl Forum’s estimate of 4,000 excess cancer deaths so low? The estimate only pertains to a much smaller subgroup of people who experienced the greatest exposure to released radiation, and therefore significantly underestimates the total number of cancers and cancer deaths that will be attributable to Chernobyl. The effects of the radiation were not limited to the highly contaminated areas in Belarus, Ukraine and Russia – they were felt in less-contaminated areas in those countries as well as in Europe and beyond.

The UCS analysis is based on radiological data provided by UNSCEAR, and is consistent with the findings of the Chernobyl Forum and other researchers.

The Union of Concerned Scientists is the leading U.S. science-based nonprofit organization working for a healthy environment and a safer world. Founded in 1969, UCS is headquartered in Cambridge, Massachusetts, and also has offices in Berkeley, Chicago and Washington, D.C.