Technical basis for narcotic chemicals and polycyclic aromatic hydrocarbon criteria. I. Water and tissue

Abstract

Abstract-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 narcotic chemicals using only the chemical's octanol-water partition coefficient K OW . It is derived from a database of LC50s comprising 156 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 is based 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 implies that the slope of the log(LC50)-log(K OW ) 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 to derive 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.

The Relationship between Nigerian Bonnylight Crude Oil-Induced Hypoglycaemia and Endogenous Serum Insulin Concentration in Male Wistar Rats: The Role of Antioxidant Vitamins C and E

“…Stress, fright, hypothermia and exhaustion are some physical manifestations that may be associated with oil spills [16]; it is also reported that crude oil consumption can induce a significant decrease in body and organ weight [17]. It was not surprising when the rats in this study showed visible signs of Nigerian Bonny Light Crude Oil (NBLCO) toxicity, which included anorexia and weakness, which corroborate a similar report on mussels where xenobiotics including polycyclic aromatic hydrocarbon (PAH) were reported to significantly reduce the feeding rate of mussels [18]. These observed physical signs could probably have been due to damage and depletion of bodily proteins as well as interference with protein synthesis by free radicals generated by NBLCO.…”

“…The concentration of oxidants in the body can be elevated by xenobiotic insults such as crude oil [18] as in this case, NBLCO. At high concentrations, oxidants are reported to have the potentials to ultimately damage all major cellular constituents [19].…”

Chronic Exposure of the Oligochaete Lumbriculus variegatus to Polycyclic Aromatic Compounds (PACs): Bioavailability and Effects on Reproduction

“…In our study, ER50s for anthracene, phenanthrene, and acridine were around 1 order of magnitude lower than 2-8 µmol/g wet weight, in agreement with the chronic CBR concept. Also, ER50s for the two homocyclic compounds were close (within a factor 2) to body residue predictions for chronic exposure to homocyclic PAHs (43). In contrast, ER50s for phenanthridine and acridone were 2 orders of magnitude lower than the chronic CBR range, suggesting additional specific modes of action of the two compounds.…”

Mechanistic sediment quality guidelines based on contaminant bioavailability: Equilibrium partitioning sediment benchmarks

“…This mixture approach is used because PAH molecules very seldom occur in sediments individually. The magnitude of toxicity is determined based on the target lipid model of narcosis toxicity [21,50,75,76]. Currently, the approach evaluates the toxic contribution of 34 PAHs.…”

“…Narcosis-specific FCV (FCV) or SCV N values (millimoles per liter, later converted to micrograms per liter) for PAHs were derived with the following general expression [76] …”