Chemical measurement strategies for enhancing natural resource damage assessment injury studies

Documenting linkage between natural resource injuries and chemical contaminant exposure is often limited by one or more factors. Few standard analytical methods that are widely used for contaminated site investigations have been successfully validated for application to tissue residue analysis. Many frequently used target analyte lists fail to adequately represent source contaminants responsible for causing injuries. Standard analytical approaches typically fail to provide the sensitivity, accuracy, and precision desired in the range of residue concentrations that bracket injury-causation thresholds, which may be in the low parts-per-billion concentration range. Matrix interferences in sediments and biota often require innovative cleanups. Environmental weathering and metabolic biotransformation of source contaminants further confound analytical strategies. Appropriate target analyte lists, analytical methods, and quality control requirements for designing injury studies are presented. Considerations for source contaminant characterization and fate and transport modeling for PACS, PCBs, an organochlorine residues are discussed. Alternative markers of exposure are examined with predicted likelihood of their success for several theoretical scenarios.