Determination of lead (Pb) levels and an assessment of environmental health risk from the vicinity of abandoned Pb mines

Nwabueze I. Elom, S. O. Ngele,

Abstract

Artisanal mining in Nigeria has caused lead (Pb) poisoning in 2010 and 2015 respectively. Available statistics revealed that in the two ugly scenarios over 500 children died and about 387 seriously sick. This study investigated 40 surface soil samples collected from the vicinity of 4 abandoned Pb mines in Ebonyi State, Nigeria. Mean concentration of Pb in the samples varied from 783 mg/kg to 1260 mg/kg. These values were compared with soil guideline values (SGVs) from 6 countries and the highest Pb content (1260) exceeded SGVs from 4 countries. To further evaluate the risk prevalent in these sites, we calculated the concentration of Pb from a sample that can be consumed by a child (representing the most vulnerable group) to reach the US EPA recommended value for Pb (3.6 μg kg-1bw day-1). These values were found to vary from 2.1 μg kg-1bw day-1 to 3.7 μg kg-1bw day-1. On the basis of a soil ingestion rate of 50 mg d-1 for a child (<6 years), we also calculated the amount of soil that a child would need to ingest daily in order to exceed this guideline.