Dominic Joel Ombati, PhD
My research in environmental geology focuses on the fate and transport of lead (Pb) along the arid section of Route 66 in San Bernardino County, California. Fate and transport research examines how chemicals degrade and how they move through the environment when released, either intentionally or unintentionally. “Transport” refers to the movement of chemicals through air, water, and soil, while “fate” describes how these chemicals change in the environment.
In my research area, anthropogenic lead (Pb) mainly originated from leaded gasoline that was deposited during the time when it was commonly used. My PhD in Earth Science research examined the spatial distribution, surface transport mechanisms, and chemical fractionation of lead (Pb) along the arid Route 66 in California. Additionally, I developed a digital educational outreach program specifically focused on lead (Pb) poisoning, targeting populations that are at a higher risk of exposure.
Scientific Research on Lead Poisoning
The Largest Known Outbreak of Lead Poisoning
The worst-documented case of childhood lead (Pb) poisoning occurred in Zamfara State, Northern Nigeria, where about 400 children died, and thousands more were left disabled due to exposure in artisanal gold mining villages (Dooyema et al., 2012; Plumlee et al., 2013). This outbreak was discovered in 2010. Gold ores containing lead-rich veins were mined manually and transported in household bags to the villages for processing (Plumlee et al., 2013).
The first stage of ore processing involved breaking down these lead-rich gold ores manually using hammers, followed by grinding the broken ore fragments with household mortars and pestles or using gasoline-powered flour mills, which were also used to grind grains for the villagers (Plumlee et al., 2013). This grinding process generated a significant amount of easily inhalable lead-rich dust.
To concentrate the gold particles, the ground lead-rich gold ores were washed with water from village sources. The concentrates were then mixed manually with liquid mercury in household cooking pots to form a gold-mercury amalgam, allowing for the extraction of small gold pieces when the mercury was vaporized (Plumlee et al., 2013). This process significantly exposed the villagers to mercury, a substance also known to be harmful to human health. The United States Environmental Protection Agency (EPA) promotes mercury-free gold mining techniques for artisanal and small-scale gold mining (ASGM). Additionally, older children worked in these hazardous conditions with their family members at the processing and sometimes processing and storage of lead (Pb) rich gold ores occurred where children played and lived (Plumlee et al., 2013).
Researchers found that children under 5 years old who survived had Blood Lead Levels (BLL) of up to 370 µg/dL (Dooyema et al., 2012). The CDC recommends a Blood Lead Level (BLL) of less than 3.5 µg/dL. Worse off, soils contaminated by washing wastes were used to make bricks for building houses in the villages (Plumlee et al., 2013). There was high lead (Pb) exposure at all stages of gold mining and processing in these artisanal gold mining villages, and that is how the worst documented lead (Pb) poisoning disaster occurred. Several agencies responded to this outbreak, and the situation has improved; however, much more needs to be done to prevent future outbreaks.
This digital educational outreach program has made deliberate online efforts to target the affected artisanal gold mining villages in Zamfara State, Nigeria, with links to credible digital educational materials on lead (Pb) poisoning.
Lead Poisoning awareness 