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Comment by garganzol | Hacker News Reader

Radiation has a notable sterilizing effect - this is why the speed of a natural decomposition is diminished. Fewer microbes leads to a slower decomposition.

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The average US background radiation dose ranges from 1.5-3.5mSv/yr, or 0.25-0.6uSv/hr. This guy went into the exclusion zone and took various measurements [1] and outside of hotspots, the radiation level there seems to be just at or above the average US background radiation level.

Now I'm sure if you go digging in the Red Forest like the Russians did at the start of the war you're going to have a bad time, but the exclusion zone has settled down significantly. Most of the highly radioactive isotopes have by definition a very short half-life.

Are you confident there are fewer microbes?

[1] http://www.chernobylgallery.com/chernobyl-disaster/radiation...

He took surface measurements. Is the same true below the surface? Bugs and microbes live deep in the soil

If the soil was sterilized the forest would be dead. The trees need soil microbes to survive.

Sensible hypothesis. Has it been confirmed?

That a forest requires living soil?

Extensively.

Most of the exclusion zone is pretty low levels of radiation so I'm not sure how effective those are other than that they're an elevated background level. The FDA says <2 kGy delays sprouting of vegatables and fruit aging 1-10 kGy decreases the levels of bacteria and >10 kGy is used for actual sterilization. Most of the zone is <1 Sv/h so you need 10k hours or more to get above the 10 kGy used for sterilization.

https://www.fda.gov/food/irradiation-food-packaging/overview....

But that to me just says that radiation definitely delays growth and a little radiation already affects a much larger organism like a plant, it’s probably hurting smaller organisms much more.

Why would it hurt smaller organisms more?

Intrinsically, smaller organisms have fewer recovery mechanisms when compared to multicellular organisms. So, it kind of makes sense for them to be more susceptible to radiation.

At the low level, it boils down to the amount of energy an organism has at its disposal: prokaryotes have no mitochondria and thus cannot usually form multicellular organisms. If radiation hits an prokaryotic organism (i.e. a single cell) - it's alone by itself and probably well gone after the hit.

If radiation hits an eukaryotic (multicellular) organism, it still is able to compensate for that (to some degree) and still remains in the breeding pool for some time after the event.

The key difference between the two is the ability to reproduce itself after the damage.

The other option is they reproduce before the damage happens, bacteria multiply quickly and being small it's less likely any one individual will get struck and killed. The FDA numbers are for acute doses so you can kill everything in a package at one time, a chronic dose of the same overall amount spread out won't sterilize because you're not going to destroy every bacteria at once.

There are 365×24 = 8760 hours in a year. So after 1 year and 52 days, we've crossed this threshold - at current levels.

So: thoroughly sterilised, if the FDA isn't totally off.

No, that dose needs to happen in a short amount of time to apply.

There's a significant difference between acute and chronic doses, the FDA are for acute dosing and there's not really numbers out there for chronic doses over that long of a timeframe with respect to food safety because it's not used. Also bacteria reproduce much faster than a year so maybe it keeps the numbers down by killing older generations sooner but it's not going to sterilize.

It's probably a good thing that the exclusion zone hasn't become a breeding ground for mutant radiation-resistant bacteria.

I was wondering why that would be a bad idea and how much radiation sterilization is used today. Apparently about 40-50% of medical single use products are sterilized beforehand using radiation.

http://large.stanford.edu/courses/2018/ph241/goronzy2/

See if you can find numbers for food irradiation. Depending on country o ly a small number of foods is permitted to get that treatment but they're usually the large volume ones like wheat or flour.

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