Nature

06
May

Birds Are Adapting to High Radiation Levels at Chernobyl

Chernobyl is still a deadly disaster zone. Just spending ten days a few miles west of the ruined nuclear power plant could expose you to as much background radiation you would receive in one year.

The exclusion zone around the plant is devoid of human habitation—we have signs and fences and guards that warn and keep people out. But wildlife—birds, insects, bats, mice, bumblebees, and more—are oblivious to all that and so suffer the genetic consequences. Timothy Mousseau studies the abandoned village of Novoshepelychi—there, he can see the effects of nuclear fallout on organisms, including tumors and deformities.

Chernobyl-containment
The New Safe Confinement, designed to contain Chernobyl's radiation, is expected to complete construction in 2015. But birds might already have a leg up when it comes to protective measures.

But recently, Mousseau and his colleagues discovered something heartening—nature is adapting. Here’s Henry Fountain writing for The New York Times:

Some bird species, they reported in the journal Functional Ecology, appear to have adapted to the radioactive environment by producing higher levels of protective antioxidants, with correspondingly less genetic damage. For these birds, Dr. Mousseau said, chronic exposure to radiation appears to be a kind of “unnatural selection” driving evolutionary change.

High doses of radiation produced by cesium, strontium, and other radioactive isotopes can be fatal. The smaller doses in and around Novoshepelych, though, can still cause mutations or other physical problems, but they may also drive organisms to adapt.

Dr. Mousseau dismisses the idea that the zone is some kind of post-apocalyptic Eden. But the latest study has given him pause, he said, because it shows the kind of adaptations that may allow some creatures—chaffinches and great tits in this case, though not barn swallows or robins—to thrive in the zone. However, it remains to be seen whether these species are truly thriving, Dr. Mousseau said.

The findings also suggest that in some cases radiation levels might have an inverse effect—birds in areas with higher radiation exposure may show greater adaptation, and thus less genetic damage, than those in areas with lower radiation levels.

Mousseau’s studies of animals in the exclusion zone could help us better understand how ionizing radiation might affect humans. Ionizing radiation is so strong that it knocks electrons out of any atom it encounters, so an exposed person runs the risk of a range of maladies, from cataracts and cancer to damage to the central nervous system.

It’s also possible that Mousseau’s results could inform our preparations for long-term human spaceflight. The dangerous radiation we encounter in space is ionizing—so perhaps someday, Chernobyl research could help devise new ways to guard astronauts against many months’ worth of accumulating radiation.