Assessment of plant uptake models used in exposure assessment tools for soils contaminated with organic pollutants

Environ Sci Technol. 2014 Oct 21;48(20):12073-82. doi: 10.1021/es501086x. Epub 2014 Sep 30.

Abstract

The aim of this study was to evaluate and improve the accuracy of plant uptake models for neutral hydrophobic organic pollutants (1 < logK(OW) < 9, -8 < logK(AW) < 0) used in regulatory exposure assessment tools, using uncertainty and sensitivity analyses. The models considered were RAIDAR, EUSES, CSOIL, CLEA, and CalTOX. In this research, CSOIL demonstrated the best performance of all five exposure assessment tools for root uptake from polluted soil in comparison with observed data, but no model predicted shoot uptake well. Recalibration of the transpiration and volatilisation parameters improved the performance of CSOIL and CLEA. The dominant pathway for shoot uptake simulated differed according to the properties of the chemical under consideration; those with a higher air-water partition coefficient were transported into shoots via the soil-air-plant pathway, while chemicals with a lower octanol-water partition coefficient and air-water partition coefficient were transported via the root. The soil organic carbon content was a particularly sensitive parameter in each model and using a site specific value improved model performance.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calibration
  • Carbon / analysis
  • Environmental Exposure / analysis*
  • Hydrophobic and Hydrophilic Interactions
  • Models, Theoretical*
  • Plant Roots / drug effects
  • Plant Roots / metabolism
  • Plant Shoots / drug effects
  • Plant Shoots / metabolism
  • Plant Transpiration / drug effects
  • Plants / drug effects
  • Plants / metabolism*
  • Soil / chemistry
  • Soil Pollutants / analysis
  • Soil Pollutants / chemistry
  • Soil Pollutants / pharmacokinetics*
  • Uncertainty

Substances

  • Soil
  • Soil Pollutants
  • Carbon