Chernobyl’s Radiation-Thriving Fungus Surprises Scientists

Cladosporium sphaerospermum, cultured at the Coimbra University Hospital Centre in Portugal. (Photo: Rui Tomé/Atlas of Mycology)

Deep inside the abandoned walls of Chernobyl’s reactor ruins, where radiation remains deadly to most life, a humble black fungus is quietly thriving. This is not a ghost of destruction—it’s a living, growing organism that appears to have adapted to one of the most hostile environments on Earth. The fungus, classified as Cladosporium sphaerospermum, may be doing something remarkable: harnessing ionizing radiation as a source of energy, transforming what destroys most life into the very thing that sustains it.

In the late 1990s, scientists surveying the Chernobyl Exclusion Zone found a surprising diversity of fungi clinging to the reactor’s walls. Among the darkly pigmented, melanin-rich molds, C. sphaerospermum stood out, as it flourished even in areas with some of the highest radioactive contamination.

One of the most fascinating findings of this funky fungus is that exposure to radiation doesn’t kill it; it may actually improve its growth. In experiments, melanin-rich fungi exposed to radiation flourished, leading to the hypothesis that melanin acts not just as a shield but as a kind of biological antenna. In a process scientists call radiosynthesis, the fungus absorbs the ionizing radiation and converts it into usable chemical energy.

Ionizing radiation, as science fiction as it sounds, is powerful enough to tear apart molecules and shred DNA, which is why it is so dangerous to humans. For a living organism not only to survive, but possibly to draw energy from that radiation, feels like a transformation of destructive force into something vital.

However, this idea of radiosynthesis, as compelling as it is, is still unproven. Scientists have not yet managed to conclusively demonstrate that this fungus performs full photosynthesis-style energy conversion. So, whether is fungus is truly “eating” radiation remains to be proven. But what we can say is this: its mere survival is enough to challenge our assumptions about where, and how, life can endure. In the radioactive ruins of Chernobyl, what we thought was death has become the unlikely cradle of extraordinary adaptation.

Beyond this scientific marvel, there is a beauty to the fungus’s existence. The deadly reactors, once symbols of human hubris and devastation, now host living organisms in slow, tenacious recovery. The pigment that gives this mold its darkness (melanin) might be what technology and disaster couldn't kill. Instead, it could become a bridge to survival.