Quantitative evaluation of atmospheric deposition flux of mercury in sediments within the city of Juarez, Mexico

Abstract

The city of Juarez is located in the northern part of Mexico at the border with the United States. This report investigates the mercury (Hg) contribution from atmospheric sources and its accumulation in the Juarez area estimated by measuring the concentration of total Hg in sediments of a small artificial pond located within the urban area of the Juarez-El Paso metroplex. The pond is intermittently fed by Hg-free (concentration below detection levels) groundwater from a private well, with sporadic input of storm overflow from a nearby water treatment facility. Total Hg concentrations in the sediments varied between 20 (detection level value) and 454 μg kg-1 dry wt, with an average value of 202.8±153.9 μg kg-1. Physical characteristics of the sediments varied among samples, although not as drastically as their Hg content did. Among the sediment parameters, the organic matter content correlated best with the Hg content. A simplified balance of total mercury supply in the aquatic system revealed a sediment Hg flux of 336.0 μg m-2 yr-1 and a maximum Hg atmospheric flux of 119 mg m-2 yr-1. Our unexpected finding of significant concentrations of Hg in the treated wastewater and in the water column stresses the need of careful consideration of all possible sources in determining mercury atmospheric deposition flux.

Department(s)

Geography, Geology, and Planning

Document Type

Article

DOI

https://doi.org/10.1023/A:1013298630997

Keywords

Artificial pond, Atmospheric flux, Juarez, Mercury, Sediment

Publication Date

11-27-2001

Journal Title

Water, Air, and Soil Pollution

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