Background: In March 2010, Medecins San Frontieres detected an outbreak of acute lead poisoning linked to low-technology gold mining in Zamfara State, northwestern Nigeria. The outbreak has killed over 400 children <5 years of age and left over 2,000 more children with permanent disabilities.
Objectives: The aims of this study were to estimate the statewide prevalence of children <5 with elevated blood lead levels (BLLs) in mining and non-mining communities and to identify factors contributing to increased BLL in children.
Methods: We took a representative, population-based sample of mining and non-mining villages throughout Zamfara. Blood samples from children, outdoor soil samples, indoor dust samples, and survey data on mining activities and other potential lead exposures were collected from 383 children <5 years of age in 383 compounds in 54 villages.
Results: 17% of compounds reported ore processing in the preceding 12 months. The prevalence of BLLs ≥10 µg/dL in children <5 was 26% in ore-processing compounds and 22% in non-ore-processing compounds. Ore-processing activities were associated with higher lead concentrations in soil, dust, and blood samples. Other factors associated with BLL were child's age and sex, breastfeeding, drinking water from a piped tap, and exposure to eye cosmetics.
Conclusion: Childhood lead poisoning is widespread in Zamfara State. Though most children's BLLs were below the recommended level for chelation therapy, environmental remediation is needed to prevent further exposures.
Implications: Childhood lead exposure is a preventable disease with largely irreversible and untreatable health effects. An understanding of the prevalence and impacts of gold mining on childhood lead exposure can help guide future environmental and public health protection efforts in mining communities.
Key words: environmental contamination, lead poisoning, mining
Table of Contents
Zamfara Lead Poisoning Outbreak.. 2
Health Effects of Lead.. 3
Lead Exposures Worldwide. 4
Global Burden of Lead Poisoning. 4
Study location.. 5
Sampling frame. 5
Sampling approach.. 6
Sample size. 7
Ethical Clearance and Informed Consent. 7
Interviews and Visual Assessments. 8
Blood Sample Collection and Analysis. 8
Dust and Soil Sampling and Analysis. 9
Water Sample Collection and Analysis. 10
Outcome, Exposure, and Effect Modifying Variables. 10
Statistical Analysis. 11
Characteristics of Study Population.. 12
Prevalence of ore processing and elevated BLL.. 13
Environmental Contamination and BLL.. 14
Linear Regression.. 17
Prevalence of Elevated BLL.. 19
Gold Ore Processing. 20
Environmental Contamination.. 21
Risk Factors for Elevated BLL.. 22
Strengths and Limitations. 23
About this Master's Thesis
|Committee Chair / Thesis Advisor|
|Prevalence and Risk Factors of Elevated Blood Lead in Children in Mining and Non-Mining Communities, Zamfara, Nigeria, 2012 ()||2018-08-28||