Certain types of fungi were discovered thriving after the devastating nuclear power plant explosion and fire at Chernobyl, Ukraine, on Saturday, April 26, 1986, contaminated large parts of that region with long-term radioactivity.
The amount of radiation released into the air at Chernobyl was 100 times greater than that measured at Hiroshima and Nagasaki in Japan at the close of World War II. The high levels of poisonous radiation at the Chernobyl reactor were lethal to victims near Ground Zero.
Two of the reactor operating staff died at the site and 134 firemen and station staff were hospitalized with acute radiation syndrome after absorbing high doses of ionizing radiation. Of these 134 people, 28 died in the following days or months. At least 14 suspected radiation-induced cancer deaths were diagnosed within the next 10 years.
Weather conditions dictated where contamination from Chernobyl ended up. A lot of it precipitated as radioactive rainfall on mountainous regions such as the Alps, the Welsh mountains, and the Scottish Highlands. Water-flows across the ground added to large variations in radioactivity over small, localized areas. Sweden and Norway also experienced heavy radioactive fallout after the toxic air wafting from the atomic blast site met a cold front, causing rain. Groundwater in these areas was also contaminated.
After the disaster, scientists arrived on the scene from all parts of the world to collect evidence, bent on figure out what had happened and the extent of the damage. Other specialists were dispatched to assist the victims of high-level radiation exposure and their families.
In the decades following the radiation release, microbiologist Nelli Zhdanova, along with colleagues from the Institute of Microbiology and Virology in Kiev, Ukraine, used robots to collect samples in the hazard zones around Chernobyl. To their great surprise, they discovered certain kinds of microbial life was thriving near the highly toxic nuclear accident site, deemed the world’s worst.
Another microbiologist named Tamas Torok at Lawrence Berkeley National Laboratory in California received more than 2,000 fungal organisms found at Chernobyl and the surrounding affected areas by Zhdanova’s team in the late 1990s. The fungi’s genetic compositions are being cryopreserved in Tork’s lab at minus-80 degrees Celsius.
Zhdanova’s team noted with interest that some types of fungus were alive inside the 30-kilometer exclusion zones. Not only that, they seemed to crave highly concentrated doses of radiation that lays waste to other organisms. Torok explained the importance of this discovery:
“Once the fungus discovered the radiation source, they grew directionally toward it. This was a brand new experience, nobody had ever seen it before.”
These special fungi had elevated amounts of melanin, the pigment that colors animal hair and skin. Could melanin absorb radiation? The evidence pointed to a ‘yes’ answer since fungi closest to the reactor had turned dark black from high melanin content but were less dark from melanin the farther away they were from the radiation source.
This research prompted another 2007 study at the Albert Einstein College of Medicine to test whether “ionizing radiation could change the electronic properties of melanin and might enhance the growth of melanized microorganisms.” These scientists determined that radiation actually helped foster the Chernobyl fungi and transformed lethal gamma rays into an energy source!
Kasthuri Venkateswaran, a research scientist at NASA’s Jet Propulsion Lab, took an interest in this natural oddity because part of his job is to keep unauthorized microbes from leaving Earth and escaping to outer space. From his perspective, microbes with not only a high tolerance to radiation but a preference for it could pose the threat by latching onto a spacecraft and surviving the flight – only to contaminate other planets or asteroids.
Meanwhile, Clay Wang, a professor at the University of Southern California School of Pharmacy, was looking into how natural products be used to make pharmaceutical medications. He wanted to see if the hardy fungi might point the way to developing drug therapies that would be equally resilient when faced with extreme conditions.
These two researchers from different disciplines joined forces to collaborate on a space-based science project. In April 2016, the duo dispatched four strains of the fungus Aspergillus nidulans to the International Space Station to see how the extremely low temperatures in space would affect the radiation-loving organisms.
“That’s when we thought, ‘Why don’t we send this radiation-resistant fungus to [the] space station and see how it grows?'”
On August 26, the Dragon space capsule plopped into the Pacific Ocean off the coast of Baja California, Mexico. The fungus onboard had survived the extreme radioactivity at Chernobyl and frigid space, where there is no atmosphere to shield radiation. Venkateswaran and Wang drove to Long Beach, an hour away, to collect the samples which were packed in cylindrical tubes and placed in coolers for transport.
Space biologist Venkateswaran and pharmacist Wang are working together to learn what new molecules the Chernobyl fungi made after being exposed to higher radiation levels in space.
Wang is isolating the biological changes in the double-dosed fungi, classifying them, and purifying them. The end goal of converting these new substances into pharmaceutical medicines will take a while to achieve. This promising new science is just blasting off.