PARENT SESSION
PT8 - Chemistry & Toxicity of Sediments
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P670) Evaluation of Toxicity in Sediment Containing PAH and Metals in the Sediments of a South Carolina Marsh.
Anderson, Paul*,1, Manoogian, Beth1, Matkoski, Susan1, Slenska, Mike2, 1 AMEC Earth and Environmental, Westford, MA, USA2 Beazer East, Inc., Pittsburgh, PA, USA
ABSTRACT- Temporal toxicity trends and the relationship between toxicity and polycyclic aromatic hydrocarbons (PAH) and metals were evaluated based on whole sediment toxicity tests performed on Mysidopisis bahia and Neanthes arenaceodentata survival. Tests were conducted in January 1999 and thereafter quarterly between April 2000 and April 2001 at seven locations containing PAH and metals and at one reference location. Temporal trends were evaluated by plotting the whole sediment toxicity results, for both species, at each sample location; performing linear regressions of mortality versus time (using the desktop application SYSTAT); and by examining the relationship between mortality (inverse of survival) and PAH and metals concentrations. The relationship between toxicity and PAH and metals was evaluated by plotting the toxicity test results from all sampling locations and events against PAH and metals concentration. In addition, correlation and linear regression analyses were conducted. Temporal analyses indicated that toxicity has generally decreased over time. Toxicity analyses indicated lower toxicity to Neanthes arenaceodentata than to Mysidopisis bahia, a typically more sensitive species. Sediments were shown to have no or very infrequent toxicity to Neanthes at most sampling locations. A greater variability was seen in the Mysidopisis bahia toxicity results over time compared to the more consistent findings for Neanthes arenaceodentata, indicating Neanthes is a better indicator of toxicity. Further, since PAH and metals concentrations are substantially greater than commonly used sediment screening benchmarks, these toxicity data provide strong evidence that use of such benchmarks for purposes of assessing potential risk to benthic invertebrates or as remedial goals are inappropriate, for at least this marsh.
Key words: sediment, toxicity tests, PAH, metals