TheApril 26, 1986occurred northwest of the Ukrainian city of Chernobyl (Ukraine) onbiggest nuclear accident in history. Despite the extent of the disaster, 25 years later its actual incidence is still unknown. An international research team now shows for the first time thatbirds may be more susceptible to radioactivity depending on the coloration of their plumage.
Theradioactivity causes oxidative stress, damages biological molecules and can have “significant” negative effects on organisms if it occurs in relatively high doses, such as those found in some areas near Chernobyl. According to the study, which is published in the journalOecology, the abundance of birds decreased as radioactivity levels increased in the peripheral areas of Chernobyl. Total,the researchers analyzed the abundance of 97 species of birdsexposed to different levels of radiation over four years.
In most birds (64 species), populations decreased with levels of radioactivity. “However, the populations of a few species (33 remaining species) experienced positive effects of radioactivity (although the magnitude of these effects was very low in some cases), perhaps due to decreased competition with other species,” he explained. Ismael Galván, lead author and researcher at the Laboratory of Ecology, Systematics and Evolution of the University of Paris-Sur (France), in statements to the SINC Agency.
The scientists focused on themelanin-generated coloration-which protect from ultraviolet radiation and generate camouflage patterns-, since the type of coloration could disturb the ability to resist the negative effects of radioactivity. ? The impact on populations depends, at least in part, on the extent of plumage that the coloration generated by pheomelanin presents, one of the two main types of melanins, which generates orange and brownish colorations ,? says the Spanish expert.
Chernobyl birds morepheomelanic (with greater extension of plumage pigmented by pheomelanin)they were “more negatively” affected by radioactivity. As the pigment consumes glutathione, which is one of the antioxidants most susceptible to radioactivity and which tends to decrease due to its effects, the ability to combat oxidative stress generated by radioactivity is “probably” diminished in these birds.
