Evaluation of an Exposure Assay to Measure Uptake of Sediment Pah by Fish

Abstract

The ecological risks of polynuclear aromatic hydrocarbons (PAH) in aquatic sediments will vary with both toxicity and bioavailability to aquatic biota. While there are standardized protocols to test the acute toxicity of sediment-borne compounds to aquatic invertebrates, there are none for assessing bioavailability to fish. We found that sediment-borne PAH caused an exposure-dependent induction of cytochrome P450 (CYP1A) enzymes in rainbow trout (Oncorhynchus mykiss) fingerlings exposed in semi-static 96 h bioassays, as shown by increased activity of ethoxyresorufin-o-deethylase (EROD). Assuming that PAH are taken up by trout due to partitioning from organic and inorganic constituents of sediments, we tested the effect of different test variables on bioaccumulation using induction as an index of exposure. EROD activity increased with exposure of fish to increasing volumes of sediments containing PAH, i.e., with increasing ratios of sediment to water. Uptake of single compounds from sandy sediments did not differ from uptake from clay or low organic (7% LOI - loss on ignition) sediments, but decreased when organic content was very high (58% LOI). Maximum induction was observed within 24 h of exposure and at 7.5 degrees C relative to 15, 22, or 28 degrees C. Storage and handling techniques had minor effects on sediment EROD induction potency. Absolute EROD activity was greater in white sucker (Catostomus commersoni) a benthic species, than in trout, a pelagic species. However, when basal (negative control) activity was accounted for, there was no difference in response between the species. Together, these experiments provide a basis for developing a standard protocol to test the bioavailability to fish of sediment-borne PAH.

Toxicity and bioaccumulation of TNT in marine fish in sediment exposures

“…This result for nitroaromatic compounds is in contrast with results obtained during studies of similar organic contaminants including PAHs, PCBs and other persistent organic pollutants, where it was reported that direct contact with sediment surfaces resulted in uptake by benthic fish (Stein et al, 1984;Hellou et al, 1994Hellou et al, , 1995Smith et al, 1996;Moermond et al, 2004;Fragoso et al, 2006). The body residue of benzo(a)pyrene via dermal contact, evaluated using anesthetized catfish (Ictalurus punctatus) placed directly on spiked sediment, was several times higher than in fish not in direct contact with the sediment (Smith et al 1996).…”

Caddis larvae (Trichoptera, Hydropsychidae) indicate delaying recovery of a watercourse polluted by pulp and paper industry

“…The experimental setup was done exploiting the study by Fragoso et al (2006). Three replicates per treatment and four fish per aquarium were used.…”

“…The positive control was retene in water (100 μg l -1 ), DMSO used as a carrier solvent. Experimental setup was done exploiting the study by Fragoso et al (2006). Around 2 cm layers (400 g) of homogenous sediment were added on the bottom of glass aquaria (dimension 19×19×32 cm, volume 10.8 l, water depth ca.…”

Historical changes in the concentrations of polycyclic aromatic hydrocarbons (PAHs) in Lake Peipsi sediments

“…The generation, deposition and redeposition of polycyclic aromatic hydrocarbons (PAHs) as widely distributed pollutants and relatively persistent compounds in water and sediments have been extensively studied during the last decades (Suess 1976;Behymer and Hites 1988;Cripps 1989;Zhang et al 1993;Trapido and Veldre 1996;Pikkarainen 2004;Quiroz et al 2005;Fragoso et al 2006;Vaine et al 2007). As many PAHs are carcinogenic the origin and pathways of PAHs in the environment have been the focus of numerous studies.…”