Why is Chernobyl deemed to not be habitable for 22,000 years despite reports and articles everywhere saying that the radiation exposure of being within the exclusion zone is less you’d get than flying in a plane or living in elevated areas like Colorado or Cornwall?
In: 12368
Living in Denver Colorado gives you about [0.8 mSv per yearm](https://www.epa.gov/radiation/radiation-sources-and-doses).
That’s about equivalent to being in the [kindergarten near Chernobyl for 1 hour.](http://www.chernobylgallery.com/chernobyl-disaster/radiation-levels/) Hang out for a couple of days and you will have accumulated as much radiation in your body as you would get an entire lifetime in Colorado.
I have a beer every few days. Not remotely enough to be medically dangerous. But if I drank a year’s worth of alcohol in one hour, I’d be in rough shape. Taking a year’s worth of radiation in one hour is exceptionally dangerous. Probably won’t kill you, cuz it’s still less than, for example, a CT scan. But you wouldn’t take a CT scan every day for the rest of your life.
In addition to what others said, take a look at what happened when Russians started moving things around. Radiation is “settled”, it’s in the ground and so on. If no human activity takes place, then radiation in the air, in those areas, is pretty much normal, but as soon as you start introducing human activity, you will make those particles fly again. All of the sensors in Chernobyl area started going up as soon as Russia entered, and those sensors were then disabled (guess why). Many ended up with radiation poisoning. Doing simple tourism is fine, but as soon as you start farming, building, driving heavy machinery, etc., whole hell can break loose.
The danger in Chernobyl is two-fold. One is the external radiation, and one is internal radiation.
The main threat of external radiation comes from gamma-active isotopes, which release gamma radiation that is difficult to shield against. This means that just by staying on Chernobyl, you are continuously absorbing at least some gamma radiation at a higher level than you normally would. This isn’t really a problem in short term, but humans living there for their entire life time would absorb much more radiation than is normal, and they would eventually start having various health issues from it (cancers, mutations causing birth defects, and even acute radiation sickness at some of the more irradiated places).
The internal radiation would be mostly caused by alpha- and beta-active isotopes absorbed from dust, or inhaled with food or water. Because of the contamination in the Chernobyl exclusion zone, it would not be safe to eat any plants grown in the area, or animals that eat the plants. The radioisotopes in the ground would get absorbed into plants, mushrooms, and lichen – and the radioisotopes then get concentrated into animals that eat the plants… and animals that eat those animals would get even higher doses of radioactive isotopes with their food. It’s the same way that environmental toxins concentrate on predators.
Gamma-active isotopes would also cause problems if ingested or inhaled in high concentrations, but they aren’t *quite* as bad for you as alpha- or beta-active isotopes.
The time of the most intensive radiation in Chernobyl exclusion zone has passed, and the radiation intensity will continue to slowly reduce. The strongest radiation is released from isotopes which decay fast, with a short half-life. But there are still a lot of radioisotopes left with medium to long half-lifes, and the threat from those isotopes continues to be significant enough that the area is considered to remain unhabitable for around 22,000 years.
ELI15 expansion on the nature of ionizing radiation:
There are three kinds of radioactive isotopes: Alpha-, beta-, and gamma-active isotopes (well, there are two other modes, but electron capture and neutron emission are not really relevant here). These release ionizing radiation in form of gamma-, alpha-, or beta-radiation. Ionizing radiation is the dangerous kind because it can cause damage to the structure of our cells and DNA.
Of these, gamma radiation consists of high energy photons (like x-rays but even stronger), while alpha particles consist of two protons and two neutrons forming a helium nucleus (He^2+) and beta particles are either electrons (e^-) or positrons (e^+).
Gamma radiation is the most difficult to shield against, since it’s not penetrates basically everything. The only way to get some protection is to make a wall that simply has enough dense mass to stop most of it. Because of this, gamma radiation is considered the most dangerous radiation *when the source of radiation is outside the body*.
However, because the gamma radiation penetrates matter so easily, most of it just zips through a human body without interacting it. Only a small amount of gamma rays hits something inside the body and cause damage.
Alpha- and beta-active isotopes are different. They release radiation in the form of alpha particles and beta particles, which are electrically charged and much larger than gamma rays. This means they interact with matter much more readily and are easily stopped by relatively thin shielding. This means alpha- and beta-active isotopes are considered the least dangerous when they remain outside of the body.
However, if the radiation source is inhaled (like dust particles suspended in the air, or even a gas like radon), or ingested with food or water, then the alpha- and beta-active isotopes become the most dangerous to humans and other life.
The most dangerous kind of isotopes are chemically similar to elements that are important to living animals. For example, strontium is chemically similar to calcium and gets absorbed into our bone structure, where it stays and irradiates our bones and bone marrow. This is not good, you will not get superpowers by replacing the calcium in your bones with strontium.
Latest Answers