The mobility, bioavailability, and human bioaccessibility of trace metals in urban soils of Hong Kong

Xiao san Luo, Shen Yu, Xiangdong Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

117 Citations (Scopus)

Abstract

Trace metals in soils may pose risks to both ecosystem and human health, especially in an urban environment. However, only a fraction of the metal content in soil is mobile and/or available for biota uptake and human ingestion. Various environmental availabilities of trace metals (Cu, Pb and Zn) in topsoil from highly urbanized areas of Hong Kong to plants, organisms, and humans, as well as the leaching potential to groundwater were evaluated in the present study. Forty selected soil samples were extracted with 0.11. M acid acetic, 0.01. M calcium chloride, 0.005. M diethylenetriaminepentaacetic acid, and simplified physiologically based extraction tests (PBET) for the operationally defined mobilizable, effectively bioavailable, potentially bioavailable, and human bioaccessible metal fractions, respectively. The metals were generally in the order of Zn. >. Cu. ~. Pb for both mobility (24%, 7.6%, 6.7%) and effective bioavailability (2.8%, 0.9%, 0.6%), Pb (18%). >. Cu (13%). >. Zn (7.4%) for potential bioavailability, and Pb (59%). ~. Cu (58%). >. Zn (38%) for human bioaccessibility. Although the variations in the different available concentrations of metals could mostly be explained by total metal concentrations in soil, the regression model predictions were further improved by the incorporation of soil physicochemical properties (pH, OM, EC). The effectively bioavailable Zn and Pb were mostly related to soil pH. Anthropogenic Pb in urban soils tended to be environmentally available as indicated by Pb isotopic composition analysis. Combining various site-specific environmental availabilities might produce a more realistic estimation for the integrated ecological and human health risks of metal contamination in urban soils.
Original languageEnglish
Pages (from-to)995-1004
Number of pages10
JournalApplied Geochemistry
Volume27
Issue number5
DOIs
Publication statusPublished - 1 May 2012

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution
  • Geochemistry and Petrology

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