Birds in Chernobyl Coping with Ionizing Radiation; Study Finds
Birds in Chernobyl are adapting to the ionizing radiation, a new study has found.
The Chernobyl disaster occurred on April 26, 1986, and caused significant damage to humans. The region has high levels of radiation. Researchers use the exclusion zone to study the effects of radiation on wildlife.
The present study showed that contrary to popular belief, some birds might actually be benefitting from the radiation.
"Previous studies of wildlife at Chernobyl showed that chronic radiation exposure depleted antioxidants and increased oxidative damage. We found the opposite - that antioxidant levels increased and oxidative stress decreased with increasing background radiation."
Ionizing radiation damages cells by producing free radicals. The body uses anti-oxidants to fight these free radicals. However, low levels of antioxidants in the body could lead to oxidative stress and damage to genetic material, which can later cause diseases.
Studies in lab have shown that small doses of ionizing radiation help humans and other organisms cope with radiation. In fact, long term exposure to low levels of radiation could help the body build resistance to high doses of radiation. However, this adaptation has never been seen outside controlled research.
For the present study, researchers used nets to capture 152 birds. These specimens belonged to 16 different species found inside and close to the Chernobyl Exclusion Zone. Researchers measured radiation exposure levels and obtained feather and blood samples, according to a press release. Levels of radiation ranged from 0.02 to 92.90 micro Sieverts per hour.
Researchers then measured the levels of glutathione, which is a key antioxidant. The team also looked for oxidative stress and DNA damage in the blood samples along with melanin levels in the feathers.
Melanin is an important animal pigment that gives color to the skin, eyes, hair and feathers. Pheomelanin and eumelanin are types of this pigment. According to researchers, animals that produce large amount of pheomelanin are more likely to suffer from negative effects of radiation because the production of pheomelanin takes up more anti-oxidants.
Researchers found that birds' antioxidant levels increased and stress decreased with the increasing levels of ionizing radiation. Also, birds that produced more pheomelanin faced higher levels of oxidative stress.
"The findings are important because they tell us more about the different species' ability to adapt to environmental challenges such as Chernobyl and Fukushima," said Galván in a news release.
The study is published in the British Ecological Society's journal Functional Ecology.