A study has found that nuclear accidents might not result in significant long-term damage to local wildlife. Researchers from the Universities of Portsmouth and the West of England, found that wildlife populations in the exclusion zone around Chernobyl have recovered and even increased since the 1986 accident, and expect that the effects of last year's Fukushima incident are likely to be similar.
"I wasn't really surprised by these findings," said Professor Jim Smith, an environmental physicist at the University of Portsmouth's School of Earth and Environmental Sciences, who co-authored the study. "There have been many high profile findings on the radiation damage to wildlife at Chernobyl but it's very difficult to see significant damage and we are not convinced by some of the claims."
Some previous studies suggested that the Chernobyl nuclear accident would result in long-term damage to local bird populations. It was thought that the birds' antioxidant defence mechanisms would sustain serious damage from radiation. However, by modelling the production of free radicals from radiation, UK-based team found that the birds' antioxidant mechanisms were capable of dealing with radiation at density levels present in Chernobyl and Fukushima.
"We showed that changes in antioxidant levels in birds in Chernobyl could not be explained by direct radiation damage," said Professor Smith. "We would expect other wildlife to be similarly resistant to oxidative stress from radiation at these levels.
"Similarly, radiation levels at Fukushima would not be expected to cause oxidative stress to wildlife," he continued. "We believe that it is likely that apparent damage to bird populations at Chernobyl is caused by differences in habitat, diet or ecosystem structure rather than radiation."
Whilst it is widely known that extremely high radiation levels damaged organisms immediately after the Chernobyl accident, Professor Smith points out that current levels are hundreds of times lower.
"We can't rule out some effect on wildlife of the radiation, but wildlife populations in the exclusion zone around Chernobyl have recovered and are actually doing well and even better than before because the human population has been removed," he explained.
The findings of Professor Smith and his colleagues, published in the journal
Biology Letters, could cast new light onto the debate surrounding the biological effects of radiation.
Mladen Biru� - Zagreb, Croatia