PNNL

Abstract

Popular media has recently shown several nightmare scenarios where threats to humans, including ‘zombies’, are released from thawing permafrost. But are these scenarios purely science fiction? Here, we delve into features of permafrost that could make it a reservoir for microbes, including pathogens, and discuss what is known about the potential for microbial and viral pathogens to emerge in a warming climate as permafrost thaws. In most cases we find that the threats to public health are minor. We show that although there is potential for bacterial human pathogens, such as anthrax, to be problematic as permafrost thaws, there is less potential for other human pathogens. Most of the microorganisms and viruses that have been identified in permafrost to date target non-human hosts, such as plants and microorganisms. Plant pathogens could pose a risk to native and introduced crops. Although fragments of human viruses have been recovered from remains preserved by permafrost, none has been shown to be infectious to humans. However, many of the microorganisms and viruses residing in permafrost have not yet been isolated or characterized. Therefore, their potential to pose future risks to humans, animals and plants warrants consideration. These risks may increase with climate change as the landscape and vegetation changes and the human population becomes increasingly exposed to thawed permafrost lands.