One question I’ve been asked a lot by journalists is, “how many people died at Hiroshima and Nagasaki?” The reason they ask isn’t because they can’t use Google, it’s because if you start hunting around you’ll get lots of different answers to this question — answers that vary by a factor of two or so.
There is, I think it should be clear, no simple answer to this. In practice, authors and reports seem to cluster around two numbers, which I will call the “low” and the “high” estimates. The “low” estimates are those derived from the estimates of the 1940s: around 70,000 dead at Hiroshima, and around 40,000 dead at Nagasaki, for 110,000 total dead. The “high” estimates are those that derive from the 1977 re-estimation: around 140,000 dead at Hiroshima, and around 70,000 dead at Nagasaki, for a total of 210,000 total dead. Given that the “high” estimates are almost double the “low” estimates, this is a significant difference. There is no intellectually defensible reason to assume that, for example, an average (105,000 dead at Hiroshima, 55,000 dead at Nagasaki) would be more accurate or meaningful.
The “low” estimates come from US government (and US military) efforts in the 1940s to estimate the dead. The “high” estimates come from attempts in the 1970s, led by the Japanese and international scientists.
– Alex Wellerstein is a historian of science at the Stevens Institute of Technology who studies the history of nuclear weapons. He is the creator of NUKEMAP.
Source: Restricted Data Blog