Assessment and Remediation of Lead Contamination in Senegal

Abstract

Background. This paper describes the impact of improper used lead-acid battery (ULAB) handling and disposal. A specific case study is presented describing the field assessment and remediation of lead contamination in a community in Senegal where at least 18 children died from lead poisoning.Objectives. The assessment and remediation process utilized to address the Senegal lead contamination has been used as a model approach to solving used lead-acid battery (ULAB) contamination in other economically depressed communities worldwide. This paper addresses exterior soil remediation with a future paper planned to address interior remediation and blood lead level declines as a marker for project success.Materials & Methods. A comprehensive field program was developed and implemented to delineate the extent of soil lead contamination. The lead-impacted soil was the source of elevated blood lead levels due to direct ingestion (children playing in impacted soil), dust migration and impacted soil tracking into homes, shops and schools. Soil lead concentrations in surface soil and at depth were determined during several site assessments. The soil lead data were collected in conjunction with blood lead testing and collection of dust wipe samples for laboratory analysis. Soil lead data were also collected during and after soil excavation activities to document remediation success.Results. The data showed widespread soil contamination throughout the community. Surface soil exhibited lead concentrations as high as approximately 20% lead (200,000 mg/kg or parts-per-million as compared to the U.S. standard of 400 mg/kg). Blood lead levels in children were highly elevated and reached as high as 613.9 μg/dL (as compared to the U.S. standard of 10 μg/dL). Bulk dust samples from inside residences were as high as 26,889 mg/kg (2.7% lead). Post-excavation soil testing demonstrated that the majority of impacted soil was removed and the exterior exposure pathway was significantly reduced.Conclusions. Lead contamination in an economically depressed community resulted in the deaths of at least 18 infants. A coalition of local community members, local and federal government agencies, and international non-governmental organizations was able to develop and implement a comprehensive assessment and remediation strategy specifically focused on minimizing future risks to the local population with minimal disruption. The implemented soil removal plan resulted in site remediation without population relocation, spanning just over two years, and being completed under the budget of USD 200,000.