ANKA, 1 October 2010 (IRIN) - Efforts to treat children poisoned by lead and to clean up contaminated sites in northern Nigeria's Zamfara State are being hampered by the reticence of communities to divulge cases, for fear of a government ban on lucrative illegal gold mining.

Lead poisoning linked to informal mining has killed over 400 children under five since March 2010, according to the United Nations. Médecins Sans Frontières (MSF), the medical relief agency, noticed high numbers of convulsions and deaths among children in Dareta and Yargalma villages in Zamfara State in March 2010, and started investigating.

"The figures are far higher than that," El-Shafi'i Muhammad Ahmad, MSF programme coordinator in Anka, northwestern Nigeria, told IRIN. "Communities deny such deaths or attribute them to spirits and other beliefs."

"The reluctance of communities to disclose ... lead-related illnesses or deaths, and ... where they conduct mining activities, is seriously hampering our efforts to identify communities at risk and pencil them down for decontamination," Ian von Linden, head of Terra Graphic, a US-based environmental engineering firm heading decontamination efforts, told IRIN. "In some cases it takes two weeks to convince a community to open up."

Heavy rains have further delayed clean-up efforts. Terra Graphic prioritized seven villages – Abare, Sunke, Dareta, Tungar Daji, Duza, Yargalma, Tungar Guru – to be decontaminated from June 2010, but has only worked in Dareta and Yargalma because rain made the others inaccessible.

Terra Graphic, with support from the UN Children's Fund (UNICEF), is helping Zamfara State authorities decontaminate. Teams from the UN Environmental Program (UNEP) and the UN office for the Coordination of Humanitarian Affairs (OCHA) arrived in Anka on 23 September to analyze the ground water.

Children most at risk

The short-term effects of lead poisoning include convulsions, loss of consciousness, and blindness; serious long-term effects are anaemia, renal failure, brain damage, and impotence, said MSF's El-Shafi'i Muhammad Ahmad.

Contamination is particularly harmful to young children due to their low immunity, and can result in death. MSF runs camps in the towns of Anka and Bukkuyum to treat children with severe and acute lead contamination.

In Zamfara State men bring home gold ore from mining sites, which their wives crush to powder with a hammer or grinding stone before flushing it with water to remove the sand and retain the gold. Young children, who are usually beside their mothers, inhale this dust, Ahmad told IRIN.

Some 3,600 children under five live in the seven most affected villages, according to a Terra Graphic survey, but four more villages were recently designated as being at severe risk. A joint study by the World Health Organization (WHO) and the Health Ministry of Zamfara State identified 180 villages where children may have been poisoned by lead, which means that up to 30,000 people could be affected.

Lucrative trade

Farming and herding communities in the mineral-rich southern part of Zamfara State have been engaged in illegal artisanal gold mining and processing the ore for over two decades.

The trade is profitable: it takes about two hours to extract about one gram of gold, which miners can sell for US$23. In comparison, 50 kg of millet, which takes four months to cultivate, sells for $40, said Umaru Na-Ta'ala, who lives in Kirsa village, where 50 children have died and there have been 20 stillbirths since 2010.

Villagers only spoke out about these deaths in July, when members of a state government "lead taskforce" - made up of environment and health ministry representatives, local chiefs, MSF, Terra Graphic, and WHO - visited their village. "We are apprehensive that disclosing the problem will make the government clamp down on our mining work," Na-Ta'ala told IRIN.

Terra Graphic decontaminates homes and villages by removing 3cm of top-soil – the extent to which contamination usually goes – and replaces it with clean soil. It then buries the contaminated soil away from the villages.