A deadly lead poisoning outbreak that began two years ago in northern Nigeria continues to claim young victims even today, an aid agency official said on Thursday, while calling on the government to do more to protect those at risk.

Ivan Gayton of Doctors Without Borders also criticised the government of oil-rich Nigeria for not taking the threat seriously, despite 4,000 children already being sickened by the outbreak linked to gold mining. Foreign aid groups have done much of the work to clean the villages affected in rural Zamfara state and provide care to the children, who likely will suffer long-term brain damage from their exposure to the lead.

“Quite frankly, the decision makers are not here today,” Gayton told journalists who gathered for the end of a two-day conference in Abuja on the outbreak. “For me, its a great disappointment.”

The existence of gold deposits in Zamfara along the border of Niger had been long known.

But it wasn't until gold prices soared in recent years that villagers began heading into the bush to search for it. Soon the poor herdsmen and farmers could sell gold for more than $23 a gram a huge sum in a country where most people live on less than $2 a day.

CDC 's reaction

It wasn't until 160 children died and others went blind and deaf that authorities in 2010 realised the region faced a lead poisoning outbreak, which the U.S. Centers for Disease Control and Prevention called “unprecedented.”

An international team of doctors and hazardous waste experts arrived in Zamfara in mid-May 2010 to clean the region, but seasonal rains halted their work.

In the time since, the cleanup work and the medical care for those affected has come almost entirely from foreign aid groups. While the government ordered the halt of mining by local villages, the practice continued. A January 2011 report showed some villages already cleaned by foreign experts showed traces of lead and mercury again because residents had begun mining again without taking any precautions.

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