Surfactants differentially impact p,p'-DDE accumulation by plant and earthworm species

Environ Sci Technol. 2007 Apr 15;41(8):2922-9. doi: 10.1021/es061893j.

Abstract

The effect of four surfactants (Triton X-100, Tween-80, rhamnolipids, cyclodextrin) at 100-1000 mg/L on p,p'-DDE phytoextraction by Cucurbita pepo (zucchini) under field conditions and p,p'-DDE bioaccumulation by earthworm species (Eisenia fetida, Lumbricus terrestris) under laboratory conditions was investigated. Abiotically, surfactants (except cyclodextrin) increased contaminant desorption from soil by 4-fold, with higher concentrations generally promoting greater release. Cyclodextrin had no effect on DDE desorption. DDE concentrations in unamended zucchini roots and stems were 30- and 7.8-fold greater than soil levels, respectively, and 1.6% of the contaminant was extracted from the soil. The surfactant effects were cultivar specific. Triton X-100 increased DDE uptake in "Costata" by 2.6-fold, yielding 5% contaminant phytoextraction. In "Goldrush", DDE accumulation decreased by 69% across all surfactants. Surfactants significantly increased DDE bioaccumulation by earthworms. For E. fetida with all surfactants and L. terrestriswith Triton X-100 and cyclodextrin, DDE accumulation increased 2.5-7.2-fold, paralleling abiotic desorption. However, Tween-80 and rhamnolipids increased DDE accumulation in L. terrestris by 74 and 36 fold, respectively. These dramatic increases in contaminant bioaccumulation do not correlate with the increased availability observed abiotically. Surfactant-mediated increases in contaminant bioavailability are an unexpectedly complex process and clearly present unanticipated concerns over pollutant exposure to nontarget organisms.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cucurbita / metabolism*
  • Dichlorodiphenyl Dichloroethylene / chemistry
  • Dichlorodiphenyl Dichloroethylene / metabolism*
  • Oligochaeta / metabolism*
  • Soil / analysis
  • Soil Pollutants / chemistry
  • Soil Pollutants / metabolism
  • Surface-Active Agents / chemistry*
  • Time Factors

Substances

  • Soil
  • Soil Pollutants
  • Surface-Active Agents
  • Dichlorodiphenyl Dichloroethylene