Emergency Cleanup: Nigerian Crisis
In March 2010, excess childhood death and illness occurring primarily amongst children under five in Zamfara State, Nigeria, was reported by Médecins Sans Frontières (MSF/Doctors Without Borders) to the state health authorities. Investigations led by the US Centers for Disease Control and Prevention (CDC), in collaboration with Federal and Zamfara State authorities, MSF, Blacksmith Institute and the World Health Organization (WHO), revealed that the outbreak was caused by acute lead poisoning associated with artisanal gold ore processing. More than 400 children under the age of five died, and hundreds more were confirmed to be at risk of death or serious acute and long-term irreversible health effects due to extremely high levels of lead. Of the children tested in two villages, 100% exceeded 10 !g/dL (the international standard maximum for lead in blood), with some levels measuring as high as 700 !g/dL.
The source was massive environmental contamination from the informal processing of lead-rich ore to extract gold. Men brought rock ore to the villages, where the women ground it into fine particles. This process resulted in the extensive dispersal of lead-containing dust throughout the villages, including within family compounds.
Seven villages were initially identified for immediate remediation. Seven more villages were later identified for clean up, including Bagega, which alone was double the size of the first seven. In all villages, including in family homes and compounds, soil lead concentrations exceeded 100,000 ppm, far above the internationally accepted standard of 400 ppm for residential areas. Primary exposure routes for children and adults were:
1) Incidental ingestion of soil and dust
2) Consumption of food contaminated by soil and dust sources
3) Ingestion of contaminated water
4) Inhalation of contaminated dust. Consequently, an estimated 2500 children accumulated life-threatening levels of lead in their blood, with thousands more at risk of permanent brain damage.
In June 2010, Zamfara State and Nigerian Federal health authorities formally requested assistance from WHO, CDC, MSF and the Blacksmith Institute to address this problem. MSF offered chelation therapy, a treatment that removes lead from the body, to children with critical levels of lead. However, in order to prevent recontamination, it was required that treated children not return to a contaminated environment. Environmental assessments indicated that lead exposure could be eliminated by the removal and replacement of topsoil and by thorough cleaning/removal of dust from all interior spaces, homes and compounds.
From June 2010 to March 2011, Blacksmith Institute conducted environmental decontamination in seven villages in collaboration with Terragraphics and local authorities. Local villagers were trained to assist with the clean-up operations, including cleaning of homes. Contaminated soil was removed to secure landfills and replaced with clean soil. In total, seven villages were remediated, including 282 residential compounds, 107 exterior areas and 23 processing ponds, allowing for MSF to provide chelation treatment for more than 1000 children. The project also removed highly contaminated material from 7 ponds that were used to make bricks for compound repairs. In addition, UNICEF and project partners mobilized the communities and established male and female advocacy programs to raise awareness, facilitate remediation and support prevention of recontamination.
Furthermore, the project trained more than 200 Ministry, village and private personnel, building local capacity to conduct remediation activities, and provided guidance and assistance to the State in how to address mineral processing activities.
This project had several significant results:
1. All seven remediated villages now have markedly reduced lead exposures and reduced risk of mortality and significant adverse health effects.
2. As a direct result of remediation, MSF was able to provide clinical services to several hundred families and chelation therapy for more than 1000 children under the age of five. These children were returned to clean homes without risk of recontamination.
3. Villagers are increasingly aware of the dangers of artisanal mining and the measures required to protect their families.
4. Zamfara and local entities now have the capacity to undertake future cleanup activities. Zamfara State and local staff have been trained to manage and supervise remediation programs and activities. Several hundred villagers and local suppliers were trained and acquired experience in implementing remediation protocols.
5. The Zamfara Ministry of Environment established a new agency to undertake remediation and regulate artisanal mining and processing.
During the remediation, a total of 114 villages were identified that were processing the lead ore. Of 73 villages that were visited, 43 villages had children with blood lead levels exceeding the 10!g/dL limit. At least 7 more villages, including Bagega and its industrial area urgently need emergency remediation.
Additional remediation activities will be required to address contamination in the other villages, as well as contaminated water. Source control, best practices for artisanal mining and facilities to support responsible mining need to be developed. In addition, follow up investigations to assess effectiveness of applied measures and remediation should be conducted.