Lead and other heavy metals, including cobalt. It allows water to be made potable and also effectively mines the water for metals that are in short supply. Cob

Lead and other heavy metals, including cobalt. It allows water to be made potable and also effectively mines the water for metals that are in short supply. Cobalt is toxic to humans. It's also used in the production of lithium-ion batteries and in short supply: A common ingredient in lithium-ion batteries, cobalt is energetically expensive to mine and accompanied by a laundry list of environmental and human costs.