Rumours that the Chernobyl nuclear disaster exclusion zone has created a haven for wildlife have been dismissed by scientists.
The area has been sealed off since 1986, when one of the Chernobyl nuclear power station’s reactors exploded in the world’s worst nuclear power station disaster. Traces of radioactive deposits were found in nearly every country in the northern hemisphere.
The area was evacuated, and a concrete “sarcophagus” erected around the ruined power station. Gradually, abandoned buildings in the exclusion zone are being enveloped by trees and grasses, and in recent years, there has been speculation that the “Zone of Alienation” had become a thriving ecosystem for rare wildlife, allowing species such as wolves to enjoy a resurgence in numbers, safe from human interference.
However, in a new paper, Anders Moller of University Paris Sud, France and Marie Curie, France, and Tim Mousseau from the University of South Carolina, US, conclude that the idea that radiation levels were not affecting animals is incorrect:
“Recent conclusions from the UN Chernobyl Forum and reports in the popular media concerning the effects of radiation from Chernobyl has left the impression that the exclusion zone is a thriving ecosystem, filled with an increasing number of rare species,” they wrote. However, “species richness, abundance and population density of breeding birds decreased with increasing levels of radiation.”
The number of birds in the most contaminated areas declined by 66% compared with sites that had normal background radiation levels. The researchers also found a decline of more than 50% in the range of species as radiation levels increase.
This study contrasts with a recent report by Robert Baker from Texas Tech University, who said that the benefits for wildlife from the lack of human activity due to the exclusion zone outweighed the risks of low-level radiation: “It can be said that the world's worst nuclear power plant disaster is not as destructive to wildlife populations as are normal human activities.”
Professor Mousseau acknowledged Professor Baker's description: “It is true that the Chernobyl region gives the appearance of a thriving ecosystem because of its protection from other human activities. However, when you do controlled ecological studies, what we see is a very clear signature of negative effects of contamination on diversity and abundance of organisms.”
The long-term consequences of the disaster for humans in the area are difficult to assess. A 2005 report prepared by the Chernobyl Forum attributed 56 direct deaths to the explosion (47 accident workers, and nine children with thyroid cancer), and estimated that there may be 4,000 extra deaths due to cancer among the 6.6 million most highly exposed.