Comparison of soil toxicity estimates using lettuce seeds and soil ciliates
- Portland State Univ., OR (United States)
- S.M. Stoller Corp., Boulder, CO (United States)
Contaminants in soils affect microbes, fungi, animals and plants, yet few tests species are available to assess soil toxicity. Many soil microbes are adapted to grow rapidly after wetting and can be used to assess contaminants in the soil solution. The authors compared the growth of the soil ciliate, Colpoda inflata, to germination and growth of lettuce (Lactuca saliva) seeds exposed to water elutriate from twenty-five soil samples suspected of being toxic. Exposure to full strength elutriate resulted in significant (p < 0.05) reduction in seed germination in 15 of 25 elutriates, five of which produced no germination. Growth (total dry weight) of the seeds that germinated was unaffected. Growth of C. inflata was reduced by more than 70% in 12 of 25 elutriates. All C. inflata were killed following exposure to the same five elutriates that resulted in no seed germination. The ciliate growth test identified three elutriates as toxic that were not identified as toxic by the seed germination test. Conversely, the seed germination test identified seven elutriates as toxic that were not toxic in the ciliate growth test. Stepwise regression using concentrations of nine metals in the soil elutriates indicated that cadmium, copper, and arsenic significantly reduced C. inflata growth (r{sup 2} = 0.77), whereas copper, arsenic, and lead significantly reduced lettuce seed germination (r{sup 2} = 0.61). The plant and microbe models showed different responses, and there was a greater correspondence between elutriate chemistry and ciliate response than in the plant tests.
- OSTI ID:
- 367536
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9640%%282
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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