PARENT SESSION
PT8 - Chemistry & Toxicity of Sediments
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P661) Use of Immunoassay Screening Technique for Rapid Sediment Characterization of PCBs at Indian Head, Maryland and Quantico, Virginia.

Guerrero, Joel^*,1, Leather, James¹, ¹ Space and Naval Warfare (SPAWAR) Systems Center, San Diego, CA, USA

ABSTRACT- Traditional sampling and laboratory analysis of contaminated sediment sites do not always provide the information needed in a time- and cost-effective manner. Space and Naval Warfare (SPAWAR) Systems Center, San Diego has been utilizing a modified Immunoassay (IA) screening method for sediments on offshore areas to provide near-real time data that can support rapid site characterization and reduce analytical costs. This study demonstrates the applicability of Enzyme Linked Immunosorbent Assay (ELISA) -based test kits for the rapid screening of polychlorinated biphenyls (PCBs) in sediment samples. This screening method was employed to support ongoing risk assessment studies at two Navy sites along the Potomac River. Approximately 175 field samples (60 at Indian Head and 115 from Quantico) were collected and within days, assayed for PCBs and other contaminants (namely poly-aromatic hydrocarbons [PAHs]). Of the total, only twenty six percent (46) were verified by laboratory analyses. The screening data validated against certified values showed less than five percent (2) false positives but no false negatives. A good correlation for PCBs were observed between the IA and GC-ECD analyses performed on the subset of duplicate samples (R² > 0.7). The data also suggested that the assay technique achieved a minimum detection level of 100-150 ug/Kg _dry (ppb) in sediments. For both sites, sediment screening resulted in an increase in the sampling density needed to identify and characterize PCB contaminated areas. Subsequently, IA data was used to prioritize field samples for laboratory analysis.

Key words: Immunoassay, screening, sediment, PCBs