DARETA, Nigeria Lead poisoning caused by illegal gold mining has killed 163 Nigerians, most of them children, since March in several remote villages in northern Nigeria, a senior government official said Friday.
Dr Henry Akpan, the health ministry's chief epidemiologist, told Reuters a total of 355 cases in six locations in Zamfara state had been reported so far and that 111 of the dead were children, many of them under the age of five.
"We discovered unusual cases of abdominal pains with vomiting, nausea and some having convulsions," Akpan said. "These people were around the area where they were digging for gold. The fatality rate is 46 percent."
Nigeria has asked for the assistance of international agencies, including the World Health Organisation (WHO) and the U.S. Centres for Disease Control and Prevention (CDC), to contain the outbreak of lead poisoning.
The villages affected are in remote parts of Zamfara, one of Nigeria's poorest states in the arid Sahel region on the southern fringe of the Sahara desert, where many people work as artisanal miners and subsistence farmers.
Dareta, one of the villages affected, is little more than a collection of mud huts some three and half hours by road and tracks from the state capital Gusau.
An official from one international agency said it was vital to clean up family compounds thought to contain residual traces of lead before the rainy season caused further contamination. But the remote location and Muslim restrictions which allow only women into some of the compounds made the work difficult.
Akpan said health officials had found children playing in water close to the mining sites when they visited. He said the number of cases had fallen since April after local authorities halted illegal mining and began evacuating residents.
"We have been able to get on top of this. The number of reported illnesses have fallen. We are winning," he said.
Although impoverished, Zamfara is thought to be rich in minerals including gold, copper, iron ore and manganese. President Goodluck Jonathan recently inaugurated a mineral processing plant and the state is keen to attract investment.
A spokesman for Zamfara state government, contacted by Reuters two days ago, said he had no information on any lead poisoning in the state, stating "there is nothing like that."
Many victims died after coming into contact with tools, soil and water contaminated with large concentrations of lead.
Too much lead can damage various systems of the body including the nervous and reproductive systems and the kidneys. Lead is especially harmful to young children and pregnant women.
Studies suggest a blood level of 10 micrograms per decilitre can have harmful effects on children's learning and behaviour, according to WHO's website.
"WHO has sent some experts to join a team, along with CDC and ministry officials, to see the extent of the contamination and shed light on whether there are any other chemicals, such as mercury," said Dr Olaokun Soyinka, a WHO health promotion official in Nigeria.
Poverty is rampant in Africa's most populous country, with the vast majority of its 140 million residents living on less than $2 a day. Unemployment is officially estimated at around 20 percent, but the actual jobless total is much higher.