R7 AM Soil Ecotoxicology and Risk Assessment
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in 327-329

(AAA-1117-742954) The uptake of aliphatic and aromatic compounds from petroleum hydrocarbon-contaminated soil by the earthworm Eisenia andrei.

(McCann) Cermak, J.¹, Stephenson, G. ^{1, 2}, Roy, J.³, Birkholz, D.⁴, Dixon, D.¹, ¹ University of Waterloo, Waterloo, Ontario, Canada² Stantec Consulting, Guelph, Ontario, Canada³ Imperial Oil Ltd., Calgary, Alberta, Canada⁴ EnviroTest Laboratories, Edmonton, Alberta, Canada

ABSTRACT- Canadian standards for petroleum hydrocarbons in soil have been developed for different boiling point distillates of crude oil. These standards are based on the toxicity, as total petroleum hydrocarbon concentration in the soil within the boiling point ranges, to soil-dwelling organisms (invertebrates, plants) and do not take into consideration the variability in the proportion of aliphatics and aromatics within petroleum products, nor differences in the bioavailability and/or toxicity of these compounds. A study was conducted using the earthworm Eisenia andrei to investigate the uptake and elimination kinetics of aliphatics and aromatics from soil spiked with individual boiling point distillates of crude oil. Earthworms were exposed to non-lethal concentrations of the distillates and sampled over a 16- or 64-day duration. On day 8 or 16, some earthworms were transferred to clean soil and sampled over an eight-day period in order to determine the elimination kinetics. Both soil and tissue samples were collected, extracted, subjected to gel permeation chromatography and separated on an alumina column to obtain both an aliphatic and aromatic fraction. These fractions were analyzed by gas chromatography-FID to obtain the total concentration of aliphatics and aromatics. Samples were also selected for gas chromatography-mass spectroscopy analysis to determine major compounds within the sample. The results of these analyses will be discussed in relation to toxicity test results and their implications for risk assessment.

Key words: earthworm, aromatics, saturates, tissue residue