Why does wildlife thrive in Chernobyl?

We received this question from Bill. Phil Sansom asked Victoria Gill, a BBC news correspondent who reported from Chernobyl early this year, to shed some light.

Phil - We put your question on the forum. User RD pointed us to a 2007 paper showing higher frequency of abnormalities in barn swallows around Chernobyl. Alancalverd said there’s a big spectrum between surviving and thriving. Others were more interested in the new Chernobyl vodka. Focus up, people.

To answer the question we needed someone with first hand experience. Victoria Gill is a BBC news correspondent who reported from Chernobyl early this year.

Victoria - The Chernobyl exclusion zone. That’s the name of the 4,000 square kilometre area that was abandoned after the 1986 disaster. And you’re exactly right about all that wildlife. Since most humans moved out, researchers moved in, at least for short periods. And they’ve recorded an increase in the population of all kinds of species: wild boars, bears, and even wolves in the zone. Apparently some species that used to live there historically but disappeared when the place was populated by people have come back.

Sir David Attenborough himself was even there for his recent Netflix series, Our Planet. So yes, wildlife seems – according to most research - to be thriving throughout the zone. That is for multiple reasons, but primarily it’s the very little human activity that there now is in that area. And crucially, the contamination isn’t as widespread and as ‘blanket ground-poisoning’ as many people believe. And in simple terms, the vast majority of the zone is relatively low in contamination.

So you can measure that as a dose. The dose per hour of radiation is often measured in a unit called microsieverts per hour. The average dose for someone in the Chernobyl exclusion zone – unless they spent a great deal of time in a very contaminated hotspot for some reason – their annual dose would be about 1,000 microsieverts. You would get about 60 microsieverts from one London to Los Angeles flight. And you’d get an instant dose of about 10,000 microsieverts from a whole body CT scan.

So now most of the zone, for wildlife and people, is relatively safe. And a few people called self-settlers who refused to abandon their homes in 1986 still live there. There’s no agriculture allowed or any developmental building of this officially contaminated land, and the locals there are actually fighting to have those restrictions lifted.

So there’s a huge amount of misunderstanding about how dangerous the zone is. But it’s something that scientists are still working to get to the bottom of, so that people in Ukraine and Belarus can be armed with the facts, and get on with their lives.

Phil - Thanks Victoria. Next time we’re answering this question from Anthony. Anthony - penne for your thoughts?

Anthony - When pasta or rice is added to boiling water, there is a sudden surge of the boiling water, to the point that the pot boils over with bubbles. Why is this?