- Life thrives in Chernobyl's reactor ruins despite extreme radiation levels
- Fungi exhibit radiotropism, growing towards ionizing radiation sources
- Melanin in fungi protects cells by absorbing and dissipating radiation energy
In places where nothing should survive, life sometimes finds surprising ways to adapt. When Ukrainian scientist Nelli Zhdanova entered the shattered remains of Chernobyl's exploded nuclear reactor in May 1997, she expected silence and emptiness. Instead, she found something remarkable. Black mould clung to the ceilings, walls and metal conduits, thriving in an environment filled with deadly radiation. This unexpected discovery began a scientific journey that reshaped our understanding of how living things respond to extreme conditions.
The explosion at Chernobyl's number four reactor on April 26, 1986, turned a simple safety check into the world's most serious nuclear accident. The massive blast released a massive amount of radioactive elements into the atmosphere, and radioactive iodine caused numerous deaths and a subsequent increase in cancer cases. To protect people, authorities established a 30-kilometer restricted zone, called the "Zone of Alienation," to keep everyone away from the highly contaminated area.
As humans moved away from the area, nature began to recover. Wolves and wild boars reappeared in the forests and fields. But inside the destroyed plant, Zhdanova found another form of life slowly spreading.
What Zhdanova observed at Chernobyl wasn't just the typical fungus that grows in abandoned areas. Previous soil tests had shown her that several types of fungi actually respond to the radioactive dust. Now they discovered that these fungi had reached the most dangerous parts of the reactor.
They called this process radiotropism-the growth of fungi in the direction of ionizing radiation. This was surprising because radiation is typically extremely destructive and can destroy organisms by damaging DNA and proteins. Despite this, Zhdanova found 36 other common fungal species in the contaminated area, along with these radiation-loving fungi.
Her discoveries opened up new possibilities-such as cleaning up radioactive areas and ways to protect future astronauts from deep-space radiation.
At the heart of this strange phenomenon was melanin-the same pigment that gives human skin, hair, and the fungi found in Chernobyl their black color. The high melanin content of the fungi made their cell walls dark. Just as dark skin protects against UV rays, Zhdanova believed that this melanin also provides protection against ionizing radiation.
This same pattern was observed in other organisms. Frogs with more melanin in the Chernobyl lakes were more protected, and the local frog population gradually darkened.
Melanin absorbs radiation, dissipates its energy, and acts as an antioxidant, helping living cells survive radiation damage.
In 2007, nuclear scientist Ekaterina Dadachova furthered this research. She found that melanin-containing fungi grew 10% faster when exposed to radioactive cesium than those that were not irradiated. Her team also suggested that these fungi may use the radiation's energy for their metabolism, a process called radiosynthesis.
Dadachova explained that ionizing radiation contains many times more energy than normal light, and it's possible that melanin converts this energy into a form fungi can use. Although radiosynthesis remains a theory, scientists have begun to identify the proteins and biological pathways involved.
Not every melanin-containing fungus exhibits this behavior, but a specific experiment revealed this tendency again. In 2018, Cladosporium sphaerospermum-the same species that Zhdanova observed at Chernobyl, was sent to the International Space Station. There, these fungi were able to grow even amid extremely dangerous galactic cosmic radiation.
This cool discovery in the ruins of Chernobyl is now helping to understand how life on Earth copes with radiation, and how humans can stay safe in space in the future.
