6 Mars 2018
Not thriving, but failing
Animals in radiation zones are not doing well
By Linda Pentz Gunter
It started with wolves. The packs around the Chernobyl nuclear plant, which exploded on April 26, 1986, were thriving, said reports. Benefitting from the absence of human predators, and seemingly unaffected by the high radiation levels that still persist in the area, the wolves, they claimed, were doing better than ever.
Appearances, however, can be deceptive. Abundant does not necessarily mean healthy. And that is exactly what evolutionary biologist, Dr. Timothy Mousseau and his team began to find out as, over the years, they traveled to and researched in and around the Chernobyl disaster site in the Ukraine. Then, when a similar nuclear disaster hit in Japan — with the triple explosions and meltdowns at Fukushima Daiichi on March 11, 2011 — Mousseau’s team added that region to its research itinerary.
Mousseau has now spent more than 17 years looking at the effects on wildlife and the ecosystem of the 1986 Chernobyl nuclear disaster. He and his colleagues have also spent the last half dozen years studying how non-human biota is faring in the wake of Fukushima. Ninety articles later, they are able to conclude definitively that animals and plants around Chernobyl and Fukushima are very far indeed from flourishing.
Great tits found near Chernobyl — bird at left is normal, right has a facial tumor
Mousseau’s findings strongly contradicted earlier work including the 2006 Chernobyl Forum report which claimed the Chernobyl zone “has become a wildlife sanctuary,” and a subsequent article published in Current Biology in 2015 that said wildlife was “thriving”around Chernobyl.
“I suppose everyone loves a Cinderella story,” speculated Mousseau, who is based at the University of South Carolina. “They want that happy ending.” But Mousseau felt sure the moment he read the Forum report, which, he noted, “contained few scientific citations,” that the findings “could not possibly be true.”
What Mousseau found was not unexpected given the levels of radiation in these areas and what is already known about the medical effects of such long-term exposures. Birds and rodents had a high frequency of tumors.
“Cancers are the first thing we think about,” Mousseau said. “We looked at birds and mice. In areas of higher radiation, the frequency of tumors is higher.” The research team found mainly liver and bladder tumors in voles and tumors on the head, body and wings of the birds studied.
But Mousseau wanted to look beyond cancers, which is what everyone expects to find and what researchers had looked for, but only in humans. There were few wildlife studies, a fact Mousseau found surprising, given nature’s ability to act as a sentinel for likely impending human health impacts.
Mousseau and his fellow researchers found cataracts in birds and rodents. Male birds had a high rate of sterility. And the brains of birds were smaller. All of these are known outcomes from radiation exposure.
“Cataracts in birds is a problem,” Mousseau said. “A death sentence.”
Mental retardation has been found among children exposed to radiation in utero. Mousseau and colleagues discovered the same pattern in the birds they studied. “Birds already have small brains, so a smaller brain size is a definite disadvantage,” he said.
There were also just fewer animals in general. “There were many fewer mammals, birds and insects in areas of higher radiation,” Mousseau said. And they had their hunch as to why.
He and his colleagues extracted sperm from the male birds they caught and were shocked to find that “up to 40% of male birds in the radiologically hottest areas were sterile.”
The birds’ sperm were either deformed or dead. None would be able to reproduce. The discovery, he said, was “not at all surprising. These are the levels of radiation known to influence reproduction. At the same time, there is no safe level of radiation below which there aren’t detectable effects.”
Fewer birds have already been observed in the contaminated areas around Fukushima, said Mousseau. “Although it’s too early to assess the long term impact on abundance and diversity around Fukushima, there are very few butterflies and many birds have declined in the more contaminated areas. If abundance is compressed, biodiversity will follow.”
The consequences of radiation exposure, says Mousseau, “will have a tremendous impact on the quality of life of these animals, and the length of quality of life. It need not necessarily be cancers,” that cause these damages he said. “There is no doubt that the levels of radiation in Chernobyl and Fukushima generate genetic damage.”
Read more about Dr. Timothy Mousseau’s work.