title: Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.
abstract: Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity.
authors.affiliation: Queen's University, Kingston, Ontario, Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Turcotte
authors.forename: Parveen
authors.initials: P
authors.lastname: Akhtar
authors.forename: Michelle
authors.initials: M
authors.lastname: Bowerman
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Kiparissis
authors.forename: R Stephen
authors.initials: RS
authors.lastname: Brown
authors.forename: Peter V
authors.initials: PV
authors.lastname: Hodson
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000002:abnormalities*; D007564:Japan; D009990:Oryzias / Q000196:embryology*; D010616:Phenanthrenes / Q000737:chemistry / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D010616:Phenanthrenes; D014874:Water Pollutants, Chemical