title: Phototoxicity of pyrene and benzo[a]pyrene to embryo-larval stages of the Pacific oyster Crassostrea gigas.
abstract: There is a growing body of evidence to suggest that certain polycyclic aromatic hydrocarbons (PAHs) pose a greater hazard to aquatic organisms than previously demonstrated, due to their potential to cause photo-induced toxicity when exposed to ultraviolet (UV) radiation. The consequences of photo-induced toxicity are reported here for embryo-larval stages of the pacific oyster Crassostrea gigas, following exposure to pyrene and benzo[a]pyrene. During laboratory investigations, significant increases in toxicity were observed in the presence of environmentally attainable levels of UV-radiation, compared with embryos exposed to PAH alone, at levels previously deemed to have little acute biological effect. The phototoxicity of pyrene and benzo[a]pyrene completely inhibited the development to the D-shell larval stage when embryos were simultaneously exposed to 5 microg l(-1) PAH and ultraviolet light (UVB = 6.3 +/- 0.1 microW/cm2 and UVA = 456.2 +/- 55 microW/cm2). A linear relationship was also demonstrated for benzo[a]pyrene phototoxicity with decreasing UV light intensity.
authors.affiliation: Ceentre for Environment, Fisheries and Aquaculture Science, Lowestoft, UK. b.p.lyons@cefas.co.uk
authors.forename: B P
authors.initials: BP
authors.lastname: Lyons
authors.forename: C K
authors.initials: CK
authors.lastname: Pascoe
authors.forename: I R B
authors.initials: IR
authors.lastname: McFadzen
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005456:Fluorescent Dyes / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D007928:Lethal Dose 50; D009153:Mutagens / Q000633:toxicity*; D010125:Ostreidae / Q000196:embryology* / Q000254:growth & development*; D010777:Photochemistry; D011721:Pyrenes / Q000633:toxicity*; D014466:Ultraviolet Rays / Q000009:adverse effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D005456:Fluorescent Dyes; D009153:Mutagens; D011721:Pyrenes; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; C030984:pyrene