The DRC produces more than 70 percent of the world's cobalt, a metal in ever-growing demand to make the batteries used in electric cars -- but there have long been fears this transition to transport touted as "clean" is coming at a high environmental and human cost.

A three-year investigation by the Environmental Investigation Agency (EIA) found that since the Tenke Fungurume mine opened in the southeast DRC in 2023, people in the area have suffered nosebleeds, repetitive coughs and vomiting blood, while miscarriages and birth defects have also been reported.

The EIA's "Toxic Transition" report found levels of sulphur dioxide, a toxic gas produced during copper-cobalt ore processing, are well in excess of international standards.

The Tenke Fungurume is owned by China's CMOC Group Ltd, which produces about half the world's mined cobalt, according to the EIA.

The plant in Lualaba province can process 30,000 tonnes of copper-cobalt ore every day, turning it into cobalt hydroxide for use in battery cells.

From 2023, nearby communities raised concerns about an increase in respiratory problems and maternal health complaints connected with the cobalt plant.

The EIA studied more than 1,200 anonymised public health records from a local clinic and found patients suffering nosebleeds, repetitive coughs and vomiting blood at a "startling rate" since the plant opened.

The report says CMOC's Tenke Fungurume operations "have apparently driven large-scale sulphur dioxide emissions that are at the heart of this crisis".

Tenke Fungurume Mining, the CMOC subsidiary which runs the mine, said it was committed to working safely and addressing concerns from nearby communities.

It argued that monitoring data from late 2024 and early 2025 showed sulphur dioxide levels within regulatory limits and that there was no clear link established between the plant's expansion and local health issues.