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A method is presented for developing sediment quality guidelines (SQG) for narcotic chemicals in general and polycyclic aromatic hydrocarbons (PAHs) in particular. The guidelines can be applied to any individual or mixture of narcotic chemicals including PAHs using only the chemical's octanol/water partition coefficient. They are derived using the final chronic values for type I narcotics developed from a database consisting of LC50s for 145 chemicals and 33 species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, and protozoans. The target lipid model is used that accounts for the variations in toxicity due to differing species sensitivities as well as chemical differences. The SQGs are derived using the equilibrium partitioning model (EqP), and the results are compared to other sediment quality guidelines. The criterion for a mixture of PAHs is based on the known additivity of narcotic chemicals. The toxic unit concentration corrected for solubility is calculated for each chemical in themixture and then summed. A total toxic unit greater than one indicates a toxic mixture. The prediction is compared to the results from anexperiment using sediment spiked singly and with a mixture of PAHs. The toxicity and amphipod abundance of field-collected sediments are also examined. [ABSTRACT FROM AUTHOR]

951,," A method is presented for developing water quality criteria (WQC) for type I narcotic chemicals in general and PAHs in particular.The criteria can be applied to any individual or mixture of narcoticchemicals using only the chemical's octanol-water partition coefficient KOW. It is derived from a database of LC50s comprising156 chemicals and 33 species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, and protozoans. A target lipid model is proposed that accounts for variations in toxicity due to differing species sensitivities and chemical differences. The model isbased on the idea that a target lipid is the site of action in the organism. Further. it is assumed that target lipid has the same lipid-octanol linear free energy relationship for all species. This impliesthat the slope of the log(LC50)-log(KOW) relationship is the same for all species. However, individual species may have varying target lipid body burdens that cause toxicity. The target lipid LC50 body burdens derived from concentration data in the water only are compared to measured total lipid LC50 body burdens for five species. They are essentially equal, indicating that the target lipid concentration is equal to the total extracted lipid concentration. The precise relationship between partitioning in target lipid and octanol is established. The species-specific body burdens are used to determine the WQC final acute value, i.e-, the 95-percentile level of protection.An acute-to-chronic ratio is used to compute the body burden corresponding to the WQC final chronic value, which is the procedure used toderive the U.S. Environmental Protection Agency water quality criteria. The criteria are expressed either as dissolved concentrations in the water column or as tissue concentrations. [ABSTRACT FROM AUTHOR]