Chernobyl Fungus Could Shield Astronauts From Space Radiation | Earth.com

The area around the Chernobyl Nuclear Power Plant, site of the 1986 disaster, continues to yield scientific surprises. While initially expected to be a lifeless exclusion zone, researchers have discovered thriving life forms, including a remarkable black fungus, Cladosporium sphaerospermum, that appears to not only tolerate high levels of radiation but actively grow towards it. This discovery, initially made in 1997 by Nelli Zhdanova, is now being investigated for potential applications ranging from cleaning up radioactive sites to protecting astronauts from the dangers of space radiation.

How the Fungus Interacts with Radiation

Cladosporium sphaerospermum isn’t simply surviving in a radioactive environment. it seems to be utilizing it. Researchers observed the fungus colonizing surfaces within the exploded reactor building itself, in areas with staggeringly high radiation levels. Previous surveys of the soil around Chernobyl had already indicated that these fungi were growing towards radioactive particles. This behavior, termed “positive radiotropism,” suggests a unique interaction with ionizing radiation – radiation with enough energy to remove electrons from atoms, causing chemical reactions.

The key to this interaction may lie in melanin, a pigment also found in human skin that protects against ultraviolet light. In these fungi, scientists hypothesize that melanin plays a similar role, reducing damage from ionizing radiation. While the exact mechanism isn’t fully understood, the fungus appears to be able to harness the energy from radiation, though the idea that radiation directly powers the organism’s metabolism – “radiosynthesis” – remains controversial and difficult to prove. Some fungi also exhibit a high concentration of hydrogen-rich materials like water, which can help unhurried certain types of space radiation, particularly energetic protons and neutrons.

Testing the Fungus in Space: The CubeLab Module

To investigate the potential of Cladosporium sphaerospermum as a radiation shield, researchers sent samples to the International Space Station (ISS) within a self-contained CubeLab module. The ISS, while partially shielded by Earth’s magnetic field, still experiences significantly more radiation than ground-level environments. The CubeLab module was equipped with Raspberry Pi computers, a camera, temperature and humidity sensors, and radiation sensors to monitor the fungus’s growth and response to space radiation.

The experiment involved a split Petri dish: one half containing potato dextrose agar inoculated with the fungus, and the other half with just the agar as a control. Radiation sensors were positioned beneath each half to compare radiation levels. The dish was oriented to face away from Earth to minimize shielding from the planet and the station’s structure. The system took photos every 30 minutes for 576 hours, collecting a wealth of data on temperature, humidity, and radiation counts.

Growth Rates and Radiation Levels on the ISS

The results showed a notable difference in growth rates between the fungus-inoculated side and the control side. Under the conditions on the ISS (an average temperature of 89°F or 31.5°C), the fungus fully covered the agar. The growth rate was approximately 21% higher on the ISS compared to ground control samples. Researchers described this as consistent with a possible “radioadaptive” response, suggesting radiation may be influencing growth, although microgravity, which alters fluid dynamics and cellular interactions, could also be a contributing factor.

Interestingly, the radiation sensor under the fungal side recorded slightly fewer radiation counts per minute than the sensor under the control side – approximately 147 versus 151 counts per minute. This difference increased as the fungal layer developed, suggesting the fungus may be providing a small degree of shielding. However, the sensors used in the experiment didn’t provide a precise “dose” measurement in millisieverts, making it difficult to quantify the shielding effect accurately.

Implications for Space Travel and ISRU

The potential implications of this research are significant, particularly for long-duration space missions. Space travel exposes astronauts to harmful radiation from galactic cosmic rays and solar particle events, which can damage DNA and increase the risk of cancer and other health problems. Current shielding methods add significant weight to spacecraft, increasing launch costs. A self-renewing, biologically-based radiation shield could offer a lighter and more sustainable solution.

This concept aligns with the broader idea of in-situ resource utilization (ISRU), where astronauts manufacture materials using resources available in space, rather than transporting everything from Earth. Cladosporium sphaerospermum, with its ability to grow from a small sample and potentially repair itself, could be a valuable component of an ISRU strategy. Researchers envision combining fungal biomass or melanin with local materials like lunar or Martian soil to create “living composites” that provide both structural support and radiation protection.

Limitations and Future Research

It’s important to note that this study was a proof-of-principle experiment with a limited scope. The fungus grew in a sealed Petri dish, making it difficult to isolate all contributing factors. The experiment doesn’t definitively prove that the fungus “lives off” radiation in the same way plants live off sunlight.

Future research will focus on using more sophisticated sensors and conducting repeated trials under different conditions to assess the stability and reliability of the shielding effect. Researchers also plan to investigate the potential for genetic modification to enhance the fungus’s radiation resistance and shielding capabilities. The full study was published in the journal Frontiers in Microbiology.

The next steps involve refining the experimental setup, improving dosimetry to accurately measure radiation levels, and exploring the long-term effects of radiation exposure on the fungus. Further investigation is also needed to understand the complex interplay between radiation, microgravity, and fungal growth, and to determine whether this remarkable organism can truly offer a viable solution for protecting future space explorers. The BBC also reported on this research in November 2025, highlighting the fungus’s ability to thrive in extreme conditions. Read more about the Chernobyl fungus on the BBC. Forbes also covered the topic in 2024, detailing the fungus’s radiotrophic properties. Forbes article on radiotrophic fungus. Additional research on fungal adaptation to ionizing radiation can be found in this NCBI article. Ionizing Radiation and Fungal Adaptation.