Residents of Goma in the east of the Democratic Republic of Congo have been warned not to use the salt-like substance that came come out alongside lava during the eruption of Mount Nyiragongo
DR Congo’s authorities warned local people on Thursday that the substance in the lava flows is unfit for human consumption.
The "whitish mineral substance" is being used by people in and around the small, local Bukumu kingdom "for domestic needs in the place of kitchen salt," the North Kivu governor's office said in a statement.
Scientific analysis revealed "siliceous substances insoluble in water, traces of heavy metals and traces of radioactive substances," the statement said.
"So it's not common kitchen salt (and) we strictly forbid the consumption of this substance, which is toxic," it said.
Mount Nyiragongo erupted on May 23, killing 32 people and destroying several hundred homes in nearby Goma.