The world needs metals, especially as we transition to renewable forms of energy that require elements like lithium. But the methods that are used to extract those metals often generate toxic waste products like mercury and arsenic. A new study has examined the impact of metal mining on rivers around the world. This study showed that around 23 million people live on roughly 164,000 square kilometers of floodplains that are impacted by tailings dams that contain toxic waste from both active and inactive mines. About 479,200 kilometers of river channels are affected by mines, and mining waste that is discharged into rivers is estimated to indirectly affect 50 times more people than those who are directly affected by toxic waste leaks from tailings dams that fail. The findings have been reported in Science.
The study authors noted that these numbers, which showed that 23.48 million people and 5.72 million livestock are directly affected by toxic waste from mines, are conservative estimates. All of that mining waste has an impact on both people and animals. Now, the researchers are hopeful that this work will spur action from our leaders.
"Our new method for predicting the dispersal of mine waste in river systems worldwide provides governments, environmental regulators, the mining industry and local communities with a tool that, for the first time, will enable them to assess the offsite and downstream impacts of mining on ecosystem and human health," said study leader Professor Mark Macklin, a Directors of the Lincoln Center for Water and Planetary Health at the University of Lincoln.
"We expect that this will make it easier to mitigate the environmental effects of historical and present mining and, most importantly, help to minimize the impacts of future mining development on communities, while also protecting food and water security."
This study has highlighted the importance of considering the environmental impacts of mines as they are developed and established to extract metals. For example, a massive deposit of lithium has recently been approved for mining in Nevada after a long legal fight. We might need that lithium to build a more sustainable future, but it will be crucial to respect the environment and the people who rely on it while that metal is mined.
Another study has recently noted that rivers around the world are under pressure and are increasingly threatened. Faced with agricultural runoff, pollution, overfishing, and engineering projects like dams, rivers are in need of protection and restoration. Research indicated that our heavily used rivers and emitting massive amounts of methane, a powerful greenhouse gas.