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3313296 
Journal Article 
Correlation of field-measured toxicity with chemical concentration and pollutant availability 
Mowat, FS; Bundy, KJ 
2001 
1 
Environment International
ISSN: 0160-4120
EISSN: 1873-6750 
PERGAMON-ELSEVIER SCIENCE LTD 
OXFORD 
27 
6 
479-489 
English 
11800430 
WOS:000172795100006 
Direct field toxicity tests were performed in two Louisiana waterways, Bayous Trepagnier and St. John, on sediments containing organic/heavy metal mixtures. Our approach involved bioluminescent bacterial toxicity assays (using DeltaTox, which qualitatively identifies polluted areas, and Microtox, which quantifies toxicity). Samples were more completely analyzed in our laboratory using inductively coupled plasma atomic emission spectroscopy (ICP-AES) and gas chromatography/mass spectrometry (GUMS). Results indicate that lead is the primary toxic metal at the sites examined, though concentrations of metals fluctuate due to spatial variation and the dynamic nature of the waterways. Polycyclic aromatic hydrocarbons (PAHs) are the most abundant group of organics measured and appear to contribute to the overall toxic response. DeltaTox located toxic hotspots where there was an average light loss of 53 - 100%. Toxicity results from both assays agree but are well correlated with concentration measurements only for certain sediment fractions. Overall, the DeltaTox/Microtox approach appears to be rapid and cost effective for on-site hotspot identification, and may increase understanding of hazards associated with heavy metal and organic contaminants in these waterways. (C) 2001 Elsevier Science Ltd. All rights reserved. 
field testing; microtox; heavy metals; organics; bioavailability