Tuesday is the 30th anniversary of the disastrous failure of reactor number four in the Chernobyl Nuclear Power Plant – located in what is now the state of Ukraine – but the effects of the accident still linger.
Chernobyl remains the biggest nuclear power failure in history, with radioactive material spread by winds over large swathes of Western Europe. The reactor is now surrounded by a 30-kilometer (19-mile) exclusion zone and it has provided a unique experiment for scientists studying the effects of radioactivity.
University of South Carolina professor of biological sciences Tim Mousseau and collaborator Anders Møller of the French Centre National de la Recherche Scientifique (CNRS) have spent 16 years studying the wildlife that now inhabits the exclusion zone.
"As a starting point for our studies of animal populations, we took our cue from the medical literature – one of the first effects observed was the presence of cataracts in the eyes of people exposed to energy from atomic bombs," Mousseau said.
"And we found that both birds and rodents show elevated frequencies and degree of cataracts in their eyes in the more radioactive areas."
The duo's research also showed that birds in the zone showed diminished brain size as a result of radioactive exposure, increased incidence of tumor formation, reduced fertility and an increase in the prevalence of developmental abnormalities.
Some animals, such as wolves, appear to have shown few disabilities due to the lingering radioactivity in the area, but other species have been hit catastrophically. Colonies of barn swallows nearly died out due to radioactive poisoning.
"In many of these populations what we're probably seeing is actually a reflection of births, deaths, and immigration," he said. "These populations would be locally extinct if it were not for constant immigration."
Plant and insect life has also suffered. Mousseau and his team published a paper in 2014 showing that dead vegetation was not being eaten by insects in the usual way, with up to 40 per cent less leaf mold consumed by invertebrates than in uncontaminated areas. This was further reflected in the amount of dead wood littering the area, indicating beetles and other wood eaters are less prevalent.
All of this poses something of a problem for the zone, since all that dead wood makes forest fires more likely. Since the trees still contain radioactive material, a fire could push it up into the atmosphere and spread it further. ®