How the race for cobalt risks turning it from miracle metal to deadly chemical

As a case in the US alleges links between tech companies and child miners in Congo, the Guardian's global environment editor assesses the dangers of element in high demand for batteries

If the prophets of technology are to be believed, the best hope for solving the climate crisis is ever more efficient batteries. But the race to produce enough materials for this energy-storage revolution is creating a host of other environmental problems, as cobalt-producing nations like the Democratic Republic of the Congo, Zambia and Cuba are discovering.

Lung disease and heart failure have been linked to high levels of this element, while the mines that produce it are blamed for devastated landscapes, water pollution, contaminated crops and a loss of soil fertility. Scientists are also investigating a possible link to cancer.

As with any chemical, the risks depend on the amount and duration of exposure. Cobalt is a metal that occurs naturally in rocks, water, plants, and animals. It is less toxic than many other metals. At low levels, it is beneficial to human health and is a component of vitamin B12.

Related: Apple and Google named in US lawsuit over Congolese child cobalt mining deaths