AN OUTBREAK OF ACUTE CHILDHOOD LEAD POISONING RELATED TO ARTISANAL GOLD ORE PROCESSING – NIGERIA, 2010

In May, 2010 the Nigerian Ministry of Health assembled a team of national and international organizations including Centers for Disease Control and Prevention to investigate reports of child death due to lead poisoning in multiple villages in northwestern Nigeria. A cross-sectional house-to-house questionnaire was developed to assess the extent of childhood lead poisoning and characterize the routes and sources of child exposure. Surveys were administered in family compounds in two of the affected villages. Investigators collected blood from select children aged <5 years, and analyzed soil, dust, and water samples for lead. Environmental samples collected within each village and in individual family compounds were also analyzed for lead content. Families from 118 compounds in the two villages were surveyed. Our findings indicate that 118 of 463 (26%) children aged <5 years had died in the last 12 month period. All children had lead poisoning (≥10 µg of lead / dL), and 97% of children had levels above the threshold for initiating chelation therapy (≥45 µg/dL). Two-thirds of households reported processing gold ore inside their family compounds. Children who died were more likely to live in a home where members broke, dried, separated, or washed gold ore. X-ray fluorescence (XRF) field analysis of lead concentrations of soil and dust ranged from 45 parts per million (ppm) to >100,000 ppm. USGS analysis of environmental samples will aid in determining the mineralogical and geochemical characteristics of the samples and further aid in the exposure assessment. Preliminary data analysis indicates that children living in family compounds that processed ore were significantly more likely to die than children living in family compounds that did not process ore (unadjusted OR 3.00, 95% CI 1.2, 7.4). Gold ore processing activities in family compounds put children at high risk for severe lead poisoning. Ongoing control measures include actively searching for other villages, medical management of lead-poisoned children, health education, and controlling mining activities. Identified lead-contaminated family compounds have undergone environmental remediation to reduce further child mortality and mitigate further child exposure.