PM09 Sediment Quality Assessment Cases
Exhibit Hall
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(PM131) Toxicity Testing of Sediment from Newton Creek System, St. Louis River AOC, Including UV Exposure.
TenEyck, M1, Balcer, M1, Broses, M2, Gieger, D1, Markee, T1, Janisch, T3, Polkinghorne, C1, 1 Lake Superior Research Institute, Superior, WI, USA2 Short Elliott Hendrickson Inc., Chippewa Falls, WI, USA3 Wisconsin DNR, Superior, WI, USA
ABSTRACT- Toxicity tests were conducted with sediment collected from Newton Creek (2000) and Hog Island Inlet (2003), Superior, Wisconsin. The tests were conducted in part of an ecological risk assessment. Testing with Newton Creek sediment consisted of a 10-d acute toxicity solid-phase sediment exposure with Chironomus tentans and a 7-d sediment-elutriate water exposure with Pimephales promelas. Hog Island sediment tests included a 10-d solid phase study with C. tentans and Lumbriculus variegatus and a 28-d solid phase study was conducted with Hyalella azteca. Due to PAH contamination in the Newton Creek and Hog Island Inlet sediments separate studies as above were conducted under UV-light. Toxic effects were observed with Newton Creek sediments and elutriate using standard toxicity tests. Survival (63.8%) of the C. tentans was significantly (p<0.05) less than the performance controls and the reference site. Mean dry weights of C. tentans were significantly reduced (p<0.001) in all of the test sediments subsequent to UV light (788 
W/cm2 UVA and 128 
W/cm2 UVB) exposure. Toxic effects were observed in Hog Island sediment, significant (p<0.05) reduction in survival of the H. azteca and L. variegatus (65% and 62.5%, respectively) was noted in comparison to performance and reference sites. A significant (p<0.05) reduction in weight was detected in the C. tentans compared to the reference site. Concurrent exposure to measured UV light (79.3-97.5 W/cm2 UVA and 4.8-6.2 W/cm2 UVB) enhanced the toxicity related to the survival endpoint compared to normal laboratory light toxicity testing.
Key words: PAHs, Sediment, UV Light