How Was the Speedy Resettlement of Hiroshima Possible?

In August 1945, the United States destroyed Hiroshima and killed most of its population with a small atomic bomb. Shortly thereafter, the Japanese Diet (parliament) approved funding for the city’s rebuilding and, by the late 1950s, the population had reached a record 400,000. Rapid economic growth and municipal expansion continued, culminating today in a city of 3 million inhabitants who can take delight in lovely parks and waterways.

Conventional wisdom says that after a city is “nuked” (a term that apparently refers to both nuclear and thermonuclear detonations), the radioactive pyre left behind remains uninhabitable for hundreds, perhaps thousands, of years. Tet, today, the radiation levels in Hiroshima are well within accepted government standards.

How do you explain this?

Easy. The “conventional wisdom” as you describe it is largley wrong. It also helps that Hiroshima was hit with a bomb that was, by today’s standards, pretty low-yield.

Check out for information on what it’s fifty years after being hit by some serious nukes. Bikini is getting fairly close to resettlement, although there is still enough leftover radioactivity in the soil that you don’t want to eat anything grown on the island. Other than that, it’s perfectly safe.

In other words, it’s uninhabitable in terms returning to a native lifestyle. If the planes and ships stop coming, and if the people don’t develop some kind of international trading economy to pay for it, they will starve to death.

People in Chicago are basically in the same boat, unless things go really wrong. At least they can grow gardens in their back yards if the economy goes to hell.

Places like that repopulate because people have short memories and the odds favor individual survival. And the space is available and cheap, and they’ll dismiss the risks. Would you take say, a 3% increase in cancer risk in order to buy a nice house with a yard for 50% less than somewhere else?

Anyone know where to find stats on post-war cancer/mortality rates for Japanese cities? Why an area repopulates might be relatively easy to understand – how good an idea it is is a whole nother question. At least Hiroshima has one advantage over cities around active volcanos (I kind of put the two together conceptually when I decided to reply): over time, the dangers in Hiroshima decrease. It’s the opposite near most volcanos.

Actually, the fractional-megaton yield of the Hiroshima and Nagasaki bombs would be considered puny for tactical weapons these days…

Another factor to consider is that the Hiroshima bomb was detonated, IIRC, roughly 1500 feet above street level. While this served nicely to maximize the bomb’s effective destructive range, it coincidentally minimized the radiation pollution of the ground itself; much of the radioactive debris was carried away on the winds rather than plowed into the ground.

Yep. But the OP asked about cities, not Pacific Islanders.

Not at all. Chicago is not farming community. Probably 99% of its food is grown more than 100 miles from the city, so eating radioactive home-grown coconuts won’t be a leading cause of death half a century after at nuclear attack.

Depends on the house, but I’d certainly consider it. Frankly, we make such choices all the time, and with much greater health risks on the line. Know anybody who smokes?

Here. The site reports a 6% increase in cancer mortality among 54,000 survivors of the blast, as compared to a control group of 37,000 who were far enough away not to have been exposed (at least at the time). A 6% cancer mortality increase is, frankly, not that bad for having a nuclear bomb incinerate your hometown.

It’s much harder to get decent data on health effects solely attributable to post-1945 environmental exposure in Hiroshima and Nagasaki. For instance, lots of sites blithely repeat the fact that breast cancer rates tripled, but often fail to point out that those cities still have a ridiculously low rate of breast cancer (as does the rest of Japan, compared to places like Europe and the U.S.). It’s really easy to triple something if you don’t start with very much of it, and when you’re done you still might not have much to write home about.

Feel free to google yourself into the statistics, however.