Reduction in the earthworm metabolomic response after phenanthrene exposure in soils with high soil organic carbon content

We evaluated the correlation between soil organic carbon (OC) content and metabolic responses of Eiserda fetida earthworms after exposure to phenanthrene (58 +/- 3 mg/kg) spiked into seven artificial soils with OC contents ranging from 1 to 27% OC. Principal component analysis of H-1 nuclear magnetic resonance (NMR) spectra of aqueous extracts identified statistically significant differences in the metabolic profiles of control and phenanthrene-exposed E. fetida in the 1% DC soil only. Partial least squares analysis identified a metabolic response in the four soils with OC values <= 11% which was well correlated to estimated phenanthrene porewater concentrations. The results suggest that the higher sorption capability of high DC soils decreased the bioavailability of phenanthrene and the subsequent metabolic response of E. fetida. (C) 2012 Elsevier Ltd. All rights reserved.