Toxicity of Halifax Harbour sediments: An evaluation of the Microtox solid phase bioassay
- Dalhousie Univ., Halifax, Nova Scotia (Canada). School for Resource and Environmental Studies
Subtidal sediments were collected from 8 stations in Halifax Harbour, N.S., in July and August, 1992, to initiate a study of sediment toxicity and hazards near the proposed location of a sewage treatment plant and outfall. A set of 110 samples was evaluated. Interstitial water from aerobic surface (0--2cm) and anaerobic subsurface (2-4cm) sediments was analyzed by the Microtox{reg_sign} toxicity test protocol; the sediment particles were analyzed using the Microtox Solid Phase Test (SPT). Toxicity was expressed as 5, 15, and 30min-EC50`s for the interstitial samples, and 5min-EC50`s for the sediments, the endpoint being the inhibition of photoluminescence of Photobacterium phosphoreum. Interstitial water from surface and subsurface sediments from all stations was usually non-toxic, when compared to a phenol standard. The mean 5min-EC50 of surface sediments (n = 57) was 5,433mg/L; the mean 5min-EC50 of subsurface sediments (n = 50) was 804 mg/L. Toxicity thresholds were compared with NRC sediment reference materials and a selection of natural sediments; then ranked based on criteria suggested by Environment Canada. Intra- and inter-sample variability in toxicity at different locations in relation to time, sediment depth, sediment properties, types and concentrations of contaminants, was evaluated by multivariate and PCA techniques. An experiment with marine reference sediments (certified for PAHs and trace metals) and their mixtures showed the ability of the STP to discriminate between different levels of contaminated sediments, i.e. a dose-response relationship was demonstrated. This laboratory-field study provided insights into the sensitivity, reproducibility, significance and discriminatory ability of the Microtox{reg_sign} SPT, characteristics necessary for its deployment in a tiered hazard assessment of contaminated harbor sediments.
- OSTI ID:
- 242294
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9626%%122
- 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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