Project Details:

Extraction and fractionation methods for exposure assessment related to trace metals, metalloids and hazardous organic compounds in terrestrial environments

Project No.:2006-039-2-600
Start date:2007-01-01
End date:2011-11-01
Division:Chemistry and the Environment Division
Objective:
- Critical evaluation of traditional single and sequential extractionschemes as well as novel flow-through fractionation methods forthe assessment of environmental exposure related to trace elements(heavy metals, metalloids) and persistent organic pollutants insoils, sediments, compost, and sewage sludge

- Establishment of a series of recommendations for accurate andcomprehensive studies on the current or potential mobility/ bioavailabilityof hazardous compounds in solid phase-soil solution systems
Description:
Accumulation of heavy metals, arsenic, and organic pollutants (e.g. polycyclic aromatic hydrocarbons, polyhalogenated species and pharmaceutical residues) in different compartments of the biosphere, and their possible mobilization under environmentally changing conditions cause adverse health effects. Correct exposure analysis concerned with soils, sediments, and sewage sludges as sinks for trace elements (TE) and persistent organic pollutants is extremely important for environmental management and risk assessment. This problem is currently attracting a great interest and widely discussed in the literature: A. Sahuquillo et al. (Trends Anal. Chem., 2003, 22, 152; doi:10.1016/S0165-9936(03)00303-0); J.R. Dean and W.C. Scott (Trends Anal. Chem., 2004, 23, 609; doi:10.1016/j.trac.2004.06.008); IUPAC book "Biophysico-Chemical Processes of Heavy Metals and Metalloids in Soil Environments" (project #2004-003-3-600) etc. Nevertheless, existing data are somewhat disembodied and there is a need for critical evaluation and generalization of reported information, particularly taking into account recent developments in flow-through extraction methods that enable to mimic natural dynamic conditions more correctly than the batchwise counterparts.

The aim of this proposal is to review at a fundamental level the progress made by different authors and institutions (e.g. in the framework of EC Standards, Measurement and Testing Programme) and then provide a series of recommendations on the use of batchwise and flow-through leaching/extraction methods for appropriate exposure analysis of TE and organic pollutants in contaminated soils, sediments, and sludges of different type and origin. It is of particular importance to demonstrate that similar methodologies have a great potential for the exposure assessment of both organic and inorganic contaminants.

Specific objectives of the proposed work are as follows:
  • critical evaluation of recent developments in the field of harmonization of leaching tests;
  • generalization of extraction methods for assessing bioavailability of hazardous organic compounds in contaminated soils, sediments, and sludges;
  • evaluation of the performance of flow-through leaching methods (extraction in microcolumns, rotating coiled columns, and stirred flow cells) when applied to fractionation explorations in certain scenarios taking into account both the type of contamination and the homogeneity of samples under study.
Progress:

July 2007 - project announcement published in Chem. Int. July/Aug 2007, p. 23

July 2010 - a review/report has been submitted to Critical Reviews in Environmental Science and Technology; reference tba

Nov 2011 - available online: 09 Aug 2011; http://dx.doi.org/10.1080/10643389.2011.556544

Project Completed

Chairman: