In recent weeks, more than 100 children have died of lead poisoning in Nigeria, health officials say.
The number has been rising since March, when residents started digging illegally for gold in areas with high concentrations of lead.
The victims were from several remote villages in the northern state of Zamfara. (map, from bbcimg.co.uk)
A Nigerian health ministry official told Reuters that a total of 163 out of 355 cases of poisoning have proved fatal.
Dr Henry Akpan, the health ministry’s chief epidemiologist, said: “[The victims] were digging for gold, but the areas also have large concentrations of lead.”
Two camps have been set up in the area by health authorities in order to treat people who are suffering symptoms of lead poisoning.
It’s during the country’s annual immunisation programme that the deaths were discovered, when officials realised there were virtually no children in several remote villages in the northern state, says the BBC’s Abdullai Kaura Abubakar in Kaduna.
Villagers said the children had died of malaria.
The high concentrations of lead were discovered when a team from international aid agency Doctors Without Borders took blood tests from local people.
BBC’s correspondent adds that Zamfara State had recently employed a Chinese company to mine gold in the area.
However villagers had also attempted to capitalise by digging for the precious metal themselves – an illegal activity in Nigeria.
According to BBC’s correspondent, it seems locals became sick after lead removed during the process of refining gold ore contaminated local water systems.