Spatial Analysis, Speciation, and Bioavailability of Mercury Contamination in Well Water Networks near Landfills

International Journal of Chemistry | Vol. 4, No. 4, April 2013 | pp. 25–32

DOI: 10.46882/2013/IJC/000055

Article Type: Original Research Paper

Title: Spatial Analysis, Speciation, and Bioavailability of Mercury Contamination in Well Water Networks near Landfills

Names of Authors: T. H. Awotunde¹, L. A. Rossi²*

Authors’ Affiliations:
¹Department of Chemistry, Federal University of Agriculture, Abeokuta, Nigeria.
²Department of Environmental Chemistry, University of São Paulo, São Paulo, Brazil.

Abstract: Municipal landfill leachate containment failures result in toxic heavy metal migrations into shallow groundwater aquifers, creating chronic ingestion risks. This study monitors the spatial variations, chemical speciation, and bioavailability indices of toxic mercury (Hg) compounds across twenty household well water sources positioned around a major urban dumpsite. Water monitoring was carried out over consecutive wet and dry cycles. Total mercury levels and organic methylmercury fractions were quantified utilizing cold vapor atomic fluorescence spectrometry (CV-AFS). Total mercury concentrations ranged from 0.45 to 4.85 μg/L, with 35% of monitored groundwater sites surpassing the strict WHO drinkable contaminant threshold of 6.0 μg/L. Speciation analysis showed that inorganic Hg(II) was the dominant species, though methylmercury accounted for up to 12.5% of total burden profiles at down-gradient coordinates. Seasonal mapping confirmed elevated total mercury mobilization during the rainy period, indicating rain-induced plume leaching. Chronic Daily Intake (CDI) projections and Hazard Quotient (HQ) risk parameters for child consumption cohorts surpassed 2.5 near historical waste dump boundaries, emphasizing an immediate public healthcare concern and a need for local membrane filtration arrays.

Keywords: Groundwater pollution; Mercury speciation; Methylmercury; Atomic fluorescence spectrometry; Landfill leachate; Hazard quotient

Manuscript Timeline: Received: August 14, 2012; Revised: September 25, 2012; Accepted: October 15, 2012; Published: April 05, 2013.

Citation: Awotunde, T. H., & Rossi, L. A. (2013). Spatial Analysis, Speciation, and Bioavailability of Mercury Contamination in Well Water Networks near Landfills. International Journal of Chemistry, 4(4), 25–32.

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