In a new study, conducted by researchers at the University of New Hampshire, the discourse concerning the vast quantities of mercury contained in permafrost is resumed, particularly in the Arctic areas. With global warming in progress, permafrost is melting and this means that large quantities of mercury are pouring into the environment.
In the new study, published in Geochemical Perspectives Letters, it is reported that this same mercury, once introduced into the environment because it was freed from frozen permafrost, can be transformed into more mobile forms and become even more toxic for wildlife and water.
In particular, the researchers focused on the reallocation of mercury caused by the melting of the permafrost north of the Arctic Circle, near Abisko, Sweden. They confirm the increased level of methylmercury, a neurotoxin, whenever the temperatures in this region fall below a certain level. According to Florencia Fahnestock, principal author of the study and doctoral student in earth sciences, the presence of methylmercury in the environment can lead to significant impacts on reproduction and populations of Arctic wildlife.
Furthermore, the very presence of neurotoxin in the environment could also lead to major problems for those who hunt wild animals to feed themselves, like some indigenous populations. This is without counting those cases in which the methylmercury ends up in the sea and therefore in the fish that are caught. Methylmercury is the most toxic form of mercury and misfortune has it that it is also the most easily assimilable version by animals.
During the study, researchers discovered that one landscape in particular, that of swampy palse, sees the highest concentrations of methylmercury compared to other landscapes. The areas they analyzed, landscapes made of water and thawed peat, allow mercury to begin the methylation process to become even more toxic due to the lack of oxygen in the sediments, a perfect mix so that the mercury can convert into methylmercury.
Furthermore, according to the researchers, the same mercury, once released into the environment due to the thaw, can be relatively easily transported by water and wind even very far from the place where it leaked.