Antimony-polluted soils risks assessment with special concern around speciation and bioaccessibility aspects
Abstract
Antimony, depending on its speciation, is toxic at low concentrations and has no biological functions. For Sb polluted soils, the exposure assessment of Humans is a crucial step. In the case of polluted soils, direct ingestion is considered as the major exposure route. In this case, the total concentration is usually characterized. However it does not reflect the concentration that is absorbed through the gastro-intestinal tract, i.e. the bioavailable concentration. The bioaccessibility research group of Europe set an in vitro model (UBM test) to determine the fraction of pollutant potentially extractable during digestive processes. If the concern of speciation as another tool for polluted matrixes characterization is growing, only little literature exists around pollutants speciation during the digestive processes. This research is devoted to the study of antimony species evolution during the UBM test, and aim to integrate this approach to polluted soil risks assessment. Low bioaccessibilities were measured for the six soils that were studied (<10%). Even if low, these concentrations should be strongly considered. In fact, when translated as the dose accessible for organism absorption, it ensured an estimation of risks associated to children exposure. It was shown that trivalent antimony was transformed to pentavalent antimony during the gastro-intestinal phase. The kinetic was fast. The UBM test is a quite fast and very simple in vitro test to express metallic pollutant bioaccessibility in case of soil ingestion. This test seemed well appropriate for polluted soil characterization in terms of risks assessment. When coupled to speciation analysis, it offered a deaper understanding of real pollutant species that infants can be exposed to.
Origin : Files produced by the author(s)
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