Bioconcentration, biotransformation, and elimination of polycyclic aromatic hydrocarbons in sheepshead minnows (Cyprinodon variegatus) Exposed to Contaminated Seawater

Abstract

Sheepshead minnows (Cyprinodon variegatus) were continuously exposed to two concentrations of polycyclic aromatic hydrocarbons (PAHs) dissolved in seawater (sigma PAH = 7.57 and 72.31 microg/L) for 36 d, followed by 8 d of depuration. The PAHs studied were naphthalene (NPH or C0-NPH), phenanthrene (PHE or C0-PHE), pyrene (PYR), 2-methylnaphthalene (C1-NPH), 1,3-dimethylnaphthalene (C2-NPH), 2-isopropylnaphthalene (C3-NPH), 9-methylphenanthrene (C1-PHE), and 9-ethylphenanthrene (C2-PHE). Uptake rate constants (k1) for NPHs increased with increasing degree of alkylation and log value of the octanol/water partition coefficient (Kow), whereas k1 values for three- and four-ring PAHs were lower despite their high log Kow values. Elimination rate constants (k2) for the homologue series of NPHs and PHEs generally increased with decreasing degree of alkylation and log Kow values. However, the depuration time did not directly correlate with the molecular size for nonalkylated PAHs. Bioconcentration factors (BCFs) were estimated from the ratio of k1 to k2 and also directly from PAH concentrations in fish tissue and water samples, and the factors generated by the two methods were very similar. A significant positive correlation was determined between log BCFs and log Kow values for the series of C0- through C3-NPH at both low (r2 = 0.985, p = 0.0077) and high (r2 = 0.956, p = 0.022) exposures, although this correlation was not determined for all the PAHs studied. As a result of increased metabolism and/ or reduced bioavailability with increasing lipophilic character, the estimated BCFs for C0- through C2-PHE and PYR were generally lower than those for C0- through C3-NPH. The two exposure levels revealed minor variations in k1 and k2 values for parent PAHs and in the temporal pattern of PAH metabolite concentrations in bile. The present results indicate that the presence and nature of alkyl groups have a significant influence on the kinetics and metabolism of PAHs in fish.

Determining oil and dispersant exposure in sea turtles from the northern Gulf of Mexico resulting from the Deepwater Horizon oil spill

“…N PH) is not as efficient as metabolism of HMWAHs (e.g. BaP) in some species of fish and birds (Roubal et al 1977, Varanasi & Gmur 1981, Jonsson et al 2004, Troisi et al 2006. Data collected in the current study clearly demonstrated that externally oiled turtles had absorbed petroleum-related PAHs via ingestion as well as inhalation (based on gastrointestinal and lung PAH findings, respectively), and that they had metabolized these compounds in the liver to more polar fluorescent aromatic compounds that were measured in their bile.…”

Effect of oil pollution on serum growth hormone (GH) levels,histology and Ultrastructure of muscles of the Nile Tilapia (Oreochromis niloticus)

“…It is therefore necessary not only to identify these pollution sources but also to monitor and manage their effects on the health of aquatic ecosystem (Jiraungkoorskul et al, 2006). Bioconcentration of PAHs from water into fish tissue depends on the balance between uptake and elimination rates (Jonsson et al, 2004).…”

Hidrocarburos aromáticos policíclicos (HAPs) (I): Toxicidad, exposición de la población y alimentos implicados

“…• A través del agua marina contaminada, que afecta a los organismos acuáticos incorporando los HAPs transportados por el agua o a partir de sedimentos contaminados (Jonsson et al, 2004). La acumulación de grandes cantidades de HAPs por los moluscos bivalvos permite su utilización como bioindicadores de contaminación medioambiental.…”