Why Can People Live in Hiroshima and Nagasaki Now, but Not Chernobyl? | Hacker News Reader

Why Can People Live in Hiroshima and Nagasaki Now, but Not Chernobyl?

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35 pointsibobev21 comments

That the Chernobyl exclusion zone has become an animal sanctuary is held out as an example of ability of ecosystems to tolerate low-level radioactivity. After the humans moved out, the animals flourished.

But I have another theory. Maybe the ecosystem isn't doing all that well. It just appears so in comparison with conditions when human activity dominated. Compared to an uncontaminated, undisturbed ecosystem, it's just doing so-so. The theory being that the presence of human activity is worse for ecosystems than low-level radiation. James Lovelock argued that we could save the rain forests from the ravages of man by burying nuclear waste in them. [1] That implicitly suggests that a little radiation is better for wildlife than human presence, at least according to Lovelock.

1 https://www.wired.com/2011/04/ff-chernobyl/

Wouldn't we expect ecosystems to tolerate low level radiation. Even among humans, the concern is long term cancer risk. It is a feat of modern society that humans routinely live long enough for cancer to be a major concern. Most wildlife would probably be dead long before the radiation can kill them.

Not sure how this applies to life like trees. I assume that they are more resilient to radiation in general, as they can live indefinitely, whereas humans seem to have finite time before cancer becomes inevitable.

We would expect them to tolerate background radiation, but evolutionarily I don't see any reason why higher radiation tolerance would be selected for. Certain around the time of things like the Permian/Triassic extinction event, organisms with a higher tolerance for UV would tend to be selected for, but otherwise I would expect other pressures to be more influential.

My hunch on that is it might not need to be selected for, cells having largely the same features. Most animals don't live as long, so they have less time to develop cancers. (Plants and fungi of course get cancers as well but the cells are immobile avoiding metastasis and they don't have single points of failure like organs.)

But it's just a hunch.

“Tolerate” as in survive, but the wildlife is clearly impacted.

I would worry that animals would accumulate radiation in their bodies over time, similar to how tuna can end up with large amounts of mercury or other toxic metals.

Only if it bioaccumulates faster than the half-life of the isotope reduces its presence. Strontium-90, e.g. has a half life of 28.5 years and a biological half life of 30 years http://hpschapters.org/northcarolina/NSDS/strontium.pdf

One of the main ways that radioactivity affects health is cancer. While there are some forms of cancer in both human and non-human animals that affect the youth, more typically they occur in late adulthood. From the standpoint of non-humans, that might not be so bad as they have already reproduced and raised their young. Humans on the other hand are understandably upset about having their golden years cut short.

> That the Chernobyl exclusion zone has become an animal sanctuary is held out as an example of ability of ecosystems to tolerate low-level radioactivity.

I'm not sure what's the meaning of that statement. Chernobyl might have become an animal sanctuary, but it is also showcases a massive drop in abundance of some species, and a ‘severely depressed’ leaf litter decomposition. The life expectancy of stray dogs in chernobyl is lower than 5-6 years.

So Chernobyl is an animal sanctuary and wildlife haven, but it's not in the coloquial sense. Human intervention is almost non existent, but the few species that manage to survive are enduring negative consequences, and it just so happens that their reproduction rate is high enough to ensure replacing.

> The life expectancy of stray dogs in chernobyl is lower than 5-6 years.

OK, and what's the life expectancy of stray dogs living in the wild that are not in the Chernobyl exclusion zone? I mean, I know that dogs can live 15-18 years as pets, but I bet life expectancy in the wild is a lot lower. I don't have hard numbers, though.

Flourished? Well I read the stray dogs you find there are very young, they die at a young age.

Which has made them an attractive study for how quickly their genes adapt. Apparently many of the features that domesticated dogs had from human-controlled breeding, like short snouts, have regressed back to their wild ancestors.

Some animal species in Chernobyl (not all) have higher levels of antioxidants than their non-Chernobyl counterparts.

> James Lovelock argued that we could save the rain forests from the ravages of man by burying nuclear waste in them.

Interesting thought, but would be a horrible thing to do to the indigenous peoples of the rain forests.

The Hanford area in Washington state is said to have a lot of wildlife also.

This is the big part:

> Little Boy had around 140 pounds of uranium, Fat Man contained about 14 pounds of plutonium and reactor number four had about 180 tons of nuclear fuel.

Also, nuclear bombs are not that efficient. Little Boy was 1.5% efficient which means only 2 kg of fission products. Fat Man was probably about the same fallout. The two bombs were detonated at altitude so the fallout spread over large area.

There was also radiation from explosion but that degraded quickly and was limited to destroyed area.

Thanks for this!

Was there more discussion of Chernobyl? I just saw one paragraph and then scrolls of ads and no more text. That site is pretty awful.

https://k1project.columbia.edu/news/hiroshima-and-nagasaki https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3875218/ https://pubmed.ncbi.nlm.nih.gov/1823351/ https://www.rerf.or.jp/en/programs/roadmap_e/health_effects-...

I want to emphasize that people also have been lived in Fukushima without problem, because it's the name of third biggest prefecture in Japan. I wish the nuclear plants had different name with smaller area name, maybe Futaba plant.

One thing to remember about Chernobyl is, it isn't only the exclusion zone which has been contaminated, but places all over Europe got radioactive contamination too. In Bavaria this affects mostly the forests (the agricultural areas have been decontaminated by stripping the top soil). There the mushrooms and as a consequence to a larger amount wild boar is affected. As a consequence one shouldn't overeat wild mushrooms from that region and a lot of wild boars have to be destroyed as unfit for consumption.

(2013)

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