title: Toxic effects of an oil spill on fish early life stages may not be exclusively associated to PAHs: studies with Prestige oil and medaka (Oryzias latipes).
abstract: Polycyclic aromatic hydrocarbons (PAHs) are assumed to be the primary determinant of oil petroleum toxicity. Since the PAH content in Prestige oil was relatively high, we investigated the effects of different oil fractions (crude or weathered oil -0.05 to 50 g/L, and shaken or sonicated water accommodated fractions, WAFs, 25-100%, v/v) on the embryo-larval development of medaka (Oryzias latipes). Concentrations of summation operator16PAHs analyzed in the incubation medium were highest in the shaken WAF followed by the crude oil, the sonicated WAF and the weathered oil. Both oils (> or =0.25 g/L) induced developmental abnormalities whereas no significant effects were seen in the WAF exposures. In vivo morphometric analysis of the surface of the gallbladder during advanced embryo organogenesis (192 h post-fertilization, hpf) revealed significant dilation in both WAF exposures (>3 x 10(4) microm(2) at > or =25%, v/v, compared to <1.7 x 10(4) microm(2) at 0%, v/v) followed by the crude oil (>2.2 x 10(4) microm(2) at > or =0.05 g/L). Fluorescent aromatic compounds were observed in the gallbladder and the yolk sac of 168-hpf embryos exposed to all oil fractions. Results suggest the presence of components in both oils capable of penetrating the chorion and inducing a toxicity not observed in the WAFs. Hence, the hazard and risk assessment of Prestige oil should not be based solely on the presence of PAHs since proximity or direct contact may induce toxicity not associated exclusively to these compounds. This research offers a new hypothesis for explaining the reported biological observations, which could be correlated to direct oil exposure rather than the traditional mechanism of waterborne PAH exposure. Further research is needed to identify those oil components responsible for toxicity.
authors.affiliation: Laboratory for Ecotoxicology, Department of the Environment, National Institute for Agricultural and Food Research and Technology, A-6, Km. 7.5, E-28040 Madrid, Spain. miguelgd@inia.es
authors.forename: Miguel
authors.initials: M
authors.lastname: González-Doncel
authors.forename: Lorena
authors.initials: L
authors.lastname: González
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-Torija
authors.forename: José María
authors.initials: JM
authors.lastname: Navas
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Tarazona
mesh_terms: D000059:Accidents; D000818:Animals; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects; D047108:Embryonic Development / Q000187:drug effects; D005704:Gallbladder / Q000002:abnormalities / Q000187:drug effects; D009990:Oryzias / Q000002:abnormalities*; D010578:Petroleum / Q000633:toxicity*; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015053:Zygote / Q000187:drug effects / Q000254:growth & development
chemical_list: D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical