TA5 Soil Ecotoxicology and Risk Assessment
203 Oregon Ballroom
8:00 AM - 12:00 PM, Tuesday
() The Use of an avoidance response test with earthworms for screening soils contaminated with petroleum hydrocarbons (PHCs).
Stephenson, G1, Holtze, D1, Feisthauer, N1, Crumb, J1, 1 Stantec Consulting, Ltd., Guelph, Ontario, Canada
ABSTRACT- A number of site soils with PHC contamination were collected and evaluated with an acute (48-h) screening test that involved assessing the avoidance response of the earthworm, Eisenia andrei. The soils originated in Alberta (Canada) and had undergone different degrees of remediation to reduce the PHC concentrations to stable residuals in soil. Biotreatment of the soils included a combination of the addition of wood bark and chips, fertilizer, and land farming. Traditional approaches to toxicity assessment of contaminated soils usually invoke the use of soil toxicity tests (acute and chronic screening tests with whole site soil samples). Environment Canada's new test method for determining the avoidance response of earthworms to soils was compared to the more traditional approaches. The results of avoidance tests with 8 site soils, two reference soils, and a negative control soil were compared to those of the acute (14-d survival) and chronic (35-d survival, 56-reproduction and growth) screening tests to determine the "sensitivity" of the different tests and to test the hypothesis that the avoidance test is equally, or more, sensitive than the other test methods. Considerable research has been conducted to support the development of the avoidance test method. However, it has not been applied with rigor to a situation involving the screening of site soil samples. The discussion of the comparative results will place this test in perspective in terms of its value as a screening tool in site soil and risk assessments.
Key words: reference soil, avoidance behaviour, earthworms, PHC-contaminated site soils