Mercury (Hg) re-emissions from soils undermine efforts to control it.1 Cities with high levels of Hg should implement proactive measures to reduce these emissions, such as adding materials such as biochar.2 Fires, amplified by climate change, convert soil pollution into mobile substances.[8] There are 1,656 gigagrams of mercury in permafrost areas, 863 gigagrams of which are in the surface layer of soil that thaws and freezes annually (27 Olympic pools), and 793 gigagrams in frozen permafrost (23 Olympic pools).[5] The mercury released from these areas pollutes rivers, groundwater, and all life forms dependent on this water.These findings have significant implications for human health and ecosystems worldwide.The article was published in Science, Volume 390, Issue 6779, page 1239, December 2025.