From black frogs to a new species of dog, radiation exposure has forced many animals near Chernobyl to mutate.
But a new study shows that not all animals in the exclusion zone responded this way.
Worms living near Chernboyl (or Chernobyl in the favored Ukrainian spelling) have developed a new “superpower”: they appear to be immune to radiation.
“Chernobyl was a tragedy of incomprehensible proportions, but we still do not have a good understanding of the consequences of the disaster for the local population,” said Dr. Sophia Tintor, lead author of the study.
‘Has the sudden shift in the environment led to species, or even individuals within a species, that are naturally more resistant to ionizing radiation?’
Worms living near Chernboyl have developed a new ‘superpower’: they appear to be immune to radiation
The 1986 Chernobyl nuclear power plant disaster turned the environment into the most radioactive landscape on Earth
The Chernobyl nuclear power plant disaster in 1986 turned the area into the most radioactive landscape on Earth.
People were evacuated, but many plants and animals still live in the region, despite high radiation levels that still persist almost forty years later.
In recent years, researchers have discovered that some animals living in the Chernobyl Exclusion Zone – the region of northern Ukraine within a 30 kilometer radius of the power plant – are physically and genetically different from their counterparts elsewhere, raising questions about the impact of chronic diseases. radiation on DNA.
In the new study, the researchers visited Chernobyl to study nematodes: small worms with simple genomes and fast reproduction, making them particularly useful for understanding fundamental biological phenomena.
“These worms live everywhere, and they live fast, so they go through dozens of generations of evolution while a typical vertebrate is still putting on its shoes,” said Matthew Rockman, professor of biology at NYU and lead author of the study.
With Geiger counters in hand to measure local radiation levels and personal protective equipment to protect against radioactive dust, they collected worms from samples of soil, rotting fruit and other organic material.
Worms were collected from locations throughout the zone with varying amounts of radiation, ranging from low levels comparable to New York City to locations with high radiation comparable to space.
Back in the NYU lab, the researchers studied the worms, partially freezing them.
Worms were collected from locations throughout the zone with varying amounts of radiation, ranging from low levels comparable to New York City to locations with high radiation comparable to space.
‘We can cryopreserve worms and then thaw them for later research,’ explains Professor Rockman.
‘That means we can prevent evolution from happening in the laboratory, something that is impossible with most other animal models, and very valuable if we want to compare animals that have experienced different evolutionary histories.’
The researchers were surprised to find that they could detect no signs of radiation damage on the genomes of the Chernobyl worms.
“This doesn’t mean Chernobyl is safe – it more likely means that nematodes are really resilient animals and can withstand extreme conditions,” Dr Tintori said.
“We also don’t know how long each of the worms we collected has been in the Zone, so we can’t be exactly sure what level of exposure each worm and its ancestors have undergone over the last forty years.”
The researchers wondered whether the lack of a genetic signature was due to the fact that the worms living in Chernobyl are extremely effective at protecting or repairing their DNA. The researchers designed a system to compare how quickly populations of worms grow and used this to measure how sensitive the offspring of each of the worms are. Twenty genetically different worms caused different types of DNA damage.
Although the lineages of worms differed from each other in the extent to which they tolerated DNA damage, these differences did not correspond to the radiation levels at each collection site.
The 1986 Chernobyl nuclear power plant disaster turned the environment into the most radioactive landscape on Earth
Their findings suggest that Chernobyl worms are not necessarily more tolerant of radiation and that the radioactive landscape has not forced them to evolve.
The results give researchers clues about how DNA repair may vary from individual to individual.
And despite the genetic simplicity of nematodes, the findings could lead to a better understanding of natural variation in humans.
“Now that we know which strains of O. tipulae are more sensitive or tolerant to DNA damage, we can use these strains to investigate why different individuals are more likely than others to suffer the effects of carcinogens,” said Dr. Tintori .
How different individuals within a species respond to DNA damage is a top priority for cancer researchers who want to understand why some people with a genetic predisposition to cancer develop the disease while others do not.
‘Thinking about how individuals respond differently to DNA-damaging agents in the environment is something that will help us get a clear picture of our own risk factors,’ Dr Tintori added.
WHAT IS THE CHERNOBYL EXCLUSION ZONE?
In 1986, an explosion at the Chernobyl nuclear power plant in the former city of Pripyat in the Soviet Union leaked radioactive material into the environment.
The explosion was caused by a fire in one of the nuclear reactors and as a result the area was evacuated.
About 116,000 people were permanently evacuated from the exclusion zone around the power plant, while towns and cities were destroyed.
Although radiation levels in the region are still considered too high for humans to return, nature has retreated to the 4,300-square-kilometer Chernobyl Exclusion Zone (CEZ) and is flourishing there.
Although radiation levels in the region are still considered too high for humans to return, animals such as wolves (pictured) have moved back to the area and are thriving.
Many believe that the region should be handed over to the animals that have settled in the area, creating a radioactive protected nature reserve.
Research into the animals and plants in the Chernobyl area is now providing clues about what the world would look like if humans suddenly disappeared.
Scientists monitor the health of plants and animals in the exclusion zone to see how they respond to chronic radiation exposure.
Camera traps set up by researchers have captured a stunning array of local wildlife, including wolves, lynx, mice, boars, deer, horses and many others, as they roamed the area.
It shows that, thirty years after the disaster, the area is far from a wasteland. Instead, life flourishes there.
