Chernobyl Death Toll: How Many People Were Killed by the Nuclear Disaster?

HBO's hit miniseries Chernobyl has supercharged public interest in the 1986 disaster, which remains the worst nuclear accident of all time.

The details of the incident—which began with the explosion of a nuclear reactor—are horrifying, with dozens of people killed by trauma and exposure to radiation as they raced to understand what had happened and contain the worst of the impact.

Millions of people would be affected by the Chernobyl disaster. Those who worked at the plant and the first responders to the explosion and subsequent toxic leak were all directly exposed to deadly radiation. Beyond them, the medical staff who treated the dying and those living in the cities, towns and villages under the drifting toxic cloud were also irradiated.

More than 600,000 people were involved in the clean-up operation in and around the nuclear plant—in which other reactors remained operational until 2000—and more than 350,000 people from the surrounding area permanently resettled outside of the 1,000 square mile exclusion zone.

United Nations estimates say that more than 3.5 million people were eventually affected and around 20,000 square miles contaminated. However, the toll of actual deaths from Chernobyl is a contentious issue, with estimates ranging widely and a paucity of Soviet documentation undermining efforts to clarify the casualty figures.

For all the disruption, the official Soviet death toll for the accident stands at just 31. This comprises the two people killed immediately by the explosion and irradiation, plus the plant workers and first responders who were exposed to fatal doses of radiation in the days, weeks and months after as clean-up operations got underway.

In 2008, a report by the United Nations Scientific Committee on the Effects of Atomic Radiation revised this tally up to 54, including those who died as a direct result of trauma or radiation sickness sustained during 1986 and 1987. This includes, for example, the crew of a helicopter that crashed while trying to drop decontaminating mixture onto the open reactor from above.

Though some groups using the same data came to a final figure of 59, many UN agencies have adopted 54 as the official total of short-term deaths from the Chernobyl disaster.

But the long-term nature of radiation-related illness means that in the decades since and in the decades ahead, many others can expect to die. Cancers caused by radiation exposure may take years to manifest, which makes it difficult to come to a full death toll from the disaster.

A far higher total was reached by the Chernobyl Forum—a group made up of the International Atomic Energy Agency, UN organizations and the governments of Belarus, Russia and Ukraine. The forum's analysis of the wider environmental and health impact of the disaster estimated that some 4,000 to 9,000 people may eventually die from additional cancers caused by Chernobyl.

The report did, however, accept that the estimate was speculative and that it was impossible to accurately predict.

The Union of Concerned Scientists suggested that up to 27,000 people would die of additional cancers, but environmental group Greenpeace proposed a higher estimate still. In a 2006 report, the organization suggested that more than 200,000 people had already died from cancers caused by Chernobyl.

chernobyl death toll, victims, died, estimates
A young woman lights a candle near flowers placed at the monument for Chernobyl victims in Slavutych, Ukraine, some 30 miles from the accident site, early on April 26, 2019. Getty/GENYA SAVILOV/AFP