RESUMO
Sediment toxicity identification and evaluation (TIE) methods are relatively simple laboratory methods designed to identify specific toxicants or classes of toxicants in sediments; however, the question of whether the same toxicant identified in the laboratory is causing effects in the field remains unanswered. The objective of our study was to determine if laboratory TIE methods accurately reflect field effects. A TIE performed on sediments collected from the Elizabeth River (ER) in Virginia identified polycyclic aromatic hydrocarbons (PAHs) as the major toxicants. Several lines of evidence indicated PAHs were the major toxic agents in the field, including elevated PAH concentrations in ER sediments, comet assay results from in situ caged Merceneria merceneria, and chemical analyses of exposed M. merceneria, which indicated high PAH concentrations in the bivalve tissue. Our final evidence was the response from test organisms exposed to ER sediment extracts and then ultraviolet (UV) radiation. UV radiation caused a toxic diagnostic response unique to PAHs. The aggregation of these various lines of evidence supports the conclusion that PAHs were the likely cause of effects in laboratory- and field-exposed organisms, and that laboratory-based TIE findings reflect causes of field impairment
