We all are exposed to small amounts of background radiation all the time. Cosmic radiation is one example; radioactive rocks are another. This background radiation is normal and harmless to us. However, there are far too many areas of the world that are contaminated by unsafe levels of radiation. Post-WW2 sci-fi movies are full of monsters created by the radioactive fall-out from atomic bomb testing. Godzilla is one of the best known examples. Godzilla, created in 1954, was soon joined by other kaiji (gigantic monsters) like Mothra and an array of colorful villains. Fears of the aftermath of a nuclear accident, and the resulting contamination, are totally valid, of course. Chernobyl, Fukushima, and the Hanford Site are 3 of the worst contaminated sites, but there are others. These and similar sites are a legacy that future generations will have to deal with.

But imagine if we had fungi that could ”eat” the radiation. How cool would that be? Then again, it also sounds like the plot of a horror film, “The Mushroom That Ate Manhattan”. Of course, it is not really that simple! Such fungi already exist in the natural world. This type of fungus is called radiotropic, which literally means “turning toward radiation”. They can use ionizing radiation as an energy source.

Radiotropic fungi, such as Cladosporium sphaerospermum, Cryptococcus neoformans, and Fusarium solani are not radioactive themselves. But, these fungi absorb radiation (such as gamma rays and X-rays) from their environment, primarily through the melanin in their cell walls. Melanin is important to help the fungus metabolize the radiation. It doesn’t remain in the fungi as active radiation. Instead, it is used by the fungi to fuel their growth. The level of radiation in the fungi is generally very low and would not be a major safety concern unless they were eaten, particularly in highly contaminated areas like Chernobyl. So, while they absorb radiation, they don’t actively emit it like radioactive materials do.

Radiotropic fungi have the potential to play a role in cleaning up nuclear waste sites, since they can survive and even thrive in high-radiation environments. Here’s how they might be useful in nuclear waste cleanup:

Because radiotropic fungi are capable of absorbing ionizing radiation, these fungi could help to reduce the radiation levels in the surrounding area over time. While they wouldn't eliminate radiation completely, they might help lower the intensity of radiation in the immediate environment, which could help in cleanup efforts. This could complement existing cleanup techniques. They might be able to grow in areas that are too contaminated for other forms of life. One of the main challenges with nuclear waste cleanup is the long-lasting effects of radiation. While certain fungi can grow in radioactive environments, scientists must do more research to determine how much of an impact fungi could have in reducing overall radiation exposure in these settings. These incredible organisms could play a key role in dealing with the toxic legacy of nuclear waste.