Outbreak of Fatal Childhood Lead Poisoning Related to Artisanal Gold Mining in Northwestern Nigeria, 2010

TLDR

The study aimed to identify the cause of a fatal childhood lead‑poisoning outbreak, assess risk factors for child mortality, and locate children under five requiring emergency chelation therapy. Researchers performed a cross‑sectional door‑to‑door survey of 119 compounds, collected blood and soil samples, and applied descriptive, bivariate, and multivariate logistic regression analyses, noting that gold ore was processed in most compounds and outlining remediation, chelation, education, and mining‑control measures. Among 463 children under five, 25% had died, 97% of those tested had blood lead levels ≥45 µg/dL, and multivariate analysis linked mortality to child age, maternal ore‑processing work, water source, and soil lead, implicating acute lead poisoning from gold ore processing as the primary cause.

Abstract

In May 2010, a team of national and international organizations was assembled to investigate children's deaths due to lead poisoning in villages in northwestern Nigeria.Our goal was to determine the cause of the childhood lead poisoning outbreak, investigate risk factors for child mortality, and identify children < 5 years of age in need of emergency chelation therapy for lead poisoning.We administered a cross-sectional, door-to-door questionnaire in two affected villages, collected blood from children 2-59 months of age, and obtained soil samples from family compounds. Descriptive and bivariate analyses were performed with survey, blood lead, and environmental data. Multivariate logistic regression techniques were used to determine risk factors for childhood mortality.We surveyed 119 family compounds. Of 463 children < 5 years of age, 118 (25%) had died in the previous year. We tested 59% (204/345) of children < 5 years of age, and all were lead poisoned (≥ 10 µg/dL); 97% (198/204) of children had blood lead levels (BLLs) ≥ 45 µg/dL, the threshold for initiating chelation therapy. Gold ore was processed inside two-thirds of the family compounds surveyed. In multivariate modeling, significant risk factors for death in the previous year from suspected lead poisoning included the age of the child, the mother's work at ore-processing activities, community well as primary water source, and the soil lead concentration in the compound.The high levels of environmental contamination, percentage of children < 5 years of age with elevated BLLs (97%, > 45 µg/dL), and incidence of convulsions among children before death (82%) suggest that most of the recent childhood deaths in the two surveyed villages were caused by acute lead poisoning from gold ore-processing activities. Control measures included environmental remediation, chelation therapy, public health education, and control of mining activities.