Radioactivity warning sign in Pripyat, a city close to the Chernobyl Nuclear Power Plant, in Ukraine
On April 26, 1986, the world woke up different. A reactor exploded in Soviet Ukraine, released radioactive clouds over Europe and forever changed the way humanity looks at nuclear energy. 40 years later, the exclusion zone is a living — and surprising — laboratory.
It was 1:23 am on April 26, 1986 when reactor number 4 at the Chernobyl nuclear power plant, located in the then Soviet Socialist Republic of Ukraine, suffered a catastrophic explosion.
It wasn’t a nuclear explosion in a strict sense. The reactor went into uncontrolled criticality (a sudden and uncontrollable increase in power), the fuel overheated, reacted with the cooling water and caused an explosion of steam that destroyed the building.
The explosion released an amount of radioactive material estimated at 400 times that released by the Hiroshima bomband contamination affected vast regions of Ukraine, Belarus and Russia.
According to one from the OECD Nuclear Energy Agency, radioactive clouds reached all of Europe, including Portugalalthough already at very low levels of radioactivity.
We were lucky with the weather: upon reaching the east coast of Spain, the main body of the radioactive cloud turned north, towards France. Our country was on the periphery of the plume and received only residual contamination.
The accident, which could have caused a calamity, occurred during a poorly planned and poorly executed security test. Plant operators had deactivated automatic protection systems to carry out the test, and the RBMK-1000 reactor, a Soviet model with Known design flawsbut never corrected, collapsed.
The political context did not help: The Soviet Union’s culture of secrecy and hierarchical obedience delayed public recognition of the severity of the disaster.
Mikhail Gorbachevwho then led the Kremlin, only days after the accident admitted the scale of the catastrophe, and the international community learned of its real extent mainly through radiation readings detected in Sweden.
The response was monumental and chaotic. Nearly 600,000 “liquidators”including firefighters, military personnel, miners and civilian workers, were mobilized to contain the fire, build the concrete sarcophagus that encapsulated the destroyed reactor and decontaminate the area.
The catastrophe could have much larger proportionswere it not for the sacrifice of some of these “likvidatory”: the “Chernobyl divers”, a group of heroes, true”.
Many died in the following yearsvictims of cancer and other diseases associated with radiation exposure. The city of Pripyat, with almost 50,000 inhabitants, was evacuated in less than 36 hours. About 120,000 people were forced to leave their homes in a 30-kilometer zone around the plant — the called exclusion zone.
As public health consequences have been and continue to be the subject of scientific debate, but it is consensual that there was a significant increase in cancers of the thyroid, especially in children exposed to radioactive iodine, with records of cancer cases linked to Chernobyl.
The World Health Organization estimates that the disaster has caused or will cause approximately 4,000 cancer deaths among the most exposed populations — a number that other independent studies consider to be highly underestimated.
More recently, researchers at the University of Bonn discovered that people have a much larger number of mutations clustered together in their DNA — on average, 2.65 per child, against 0.88 in the control group.
The majority of these mutations are located in non-coding zones of the genomewhich makes the relatively low disease risk. Still, Chernobyl’s genetic legacy spans generations.
However, life goes on — and in ways no one anticipated.
The famous ones, around 800 animals that live in the surroundings of the plant, have become genetically distinct from any other population canine disease in the world, not due to the accumulation of mutations, but due to mechanisms that science still does not fully understand.
Os tree frogs of the area have developed dark pigmentation, rich in melanin, which appears to function as radiation shield — and several studies show that they are.
Os Przewalski’s horsesone of the rarest equine species in the world and at risk of extinction, . Boars, bears, lynxes and even returned to a region that Man abandoned — and made it a of the largest wildlife sanctuaries in Europe.
40 years later, Chernobyl is at the same time a open wound in history of humanity and a fascinating laboratory of life’s resilience.
The reactor remains sealed under a steel and concrete dome. The exclusion zone remains closed. But nature, stubborn as always, did not read the warning — and continues to thrive.
