Bioavailability, accumulation and effects of heavy metals in sediments with special reference to United Kingdom estuaries: a review

VOLUME 1 - Metals Cadmium Chromium Copper Lead Mercury Nickel Silver Tin Zinc VOLUME 2 - Organics Acrolein Atrazine Carbofluran Chlordane Chlorpyrifos Cyanide Diazinon Diflubenzuron Dioxins Famphur Fenvalerate Mirex Paraquat Pentachlorophenol Polychlorinated Biphenyls Polycyclic Aromatic Hydrocarbons Sodium Monofluoroacetate Toxaphane VOLUME 3 - Metaloids, Radiation, Index Arsenic Boron Molybdenum Selenium Radiation Index

Handbook of chemical risk assessment : health hazards to humans, plants, and animals

Since their heterotrophic origin, animals have been faced with a continual input of foreign compounds, so-called xenobiotics, from their food sources, e.g. polybromomethanes and alkyl halides in seaweeds (Gschwend et al. 1985) and defensive toxins in other animals (Bakus and Kawaguchi 1984); and from the attacks of predators, e.g. venoms of certain gastropods and cephalopods (Fange 1984). For example, “animal-plant warfare” is considered to be a major selective pressure in driving the evolution of some of the gene families of the biotransformation enzyme, cytochrome P-450 (Nebert et al. 1989b). Over time, additional sources of xenobiotics have included erosion of hydrocarbon-containing shales, and oil seepage from natural reservoirs (started at least 100,000 years ago) (Farrington 1985), hostile environments such as the high sulphide levels around deep sea hydrothermal vents (Vetter et al. 1987), and, in more recent years, man’s multifarious industrial and other activities (Mix 1984). Central to the defense against such an enormous and diverse number of potentially toxic compounds is an impressive array of enzymes, which function ideally to detoxify and eliminate xenobiotics from an organism. The biological significance of biotransformation enzymes is increased by the inducibility of some of them by xenobiotics, and by their metabolism of certain xenobiotics to molecular species more toxic, mutagenic or carcinogenic than the parent compound. Elaboration of the qualitative and quantitative aspects of organic xenobiotic metabolism in marine invertebrates, and the function and regulation of the enzymes involved, is important for several reasons, viz. predicting and modelling the fate and toxicity of xenobiotics in marine organisms and ecosystems (e.g. Harris et al. 1984); development of specific indices of biological effect for use in pollution monitoring and impact assessment (e.g. Malins et al. 1985; Kleinow et al. 1987; Payne et al. 1987; Bayne et al. 1988); and understanding the evolutionary relationships of the biotransformation pathways in different phylogenetic groups, and the use of the pathways in invading, or exploiting, ecological time and space to create new niches.

Organic Xenobiotic Metabolism in Marine Invertebrates

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Cadmium Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

Substantial progress has been made in the last two decades to evaluate the impact of physical and chemical genotoxins in aquatic organisms. This overview (a) summarises the major high lights in this stimulating area of research, (b) compares the developments in this field with the developments in mammalian genotoxicological studies, where appropriate, (c) introduces 18 different articles presented in this special issue of Mutation Research in the backdrop of main advances and, (d) hypothesises on future directions of research in this exciting field.

Genotoxicological studies in aquatic organisms: an overview.

The teratogenic effects of environmental levels of the mutagen, benzo(a)pyrene (BaP), were investigated using the purple sea urchin (Strongylocentrotus purpuratus) and were related to embryonic cytotoxicity and genotoxicity as evidenced by the presence of aberrant chromosome arrangements during mitosis. Developmental abnormalities were observed in gastrulae treated with initial BaP concentrations of 1 to 50 ng/ml relative to solvent (ethanol)-treated control embryos. However, genotoxic effects were significant at the lowest BaP dose tested, 0.5 ng/ml. When compared to seawater and ethanol control embryos, fewer mitotic figures and increased frequencies of abnormal mitoses were present in BaP-treated gastrulae. Micronucleus formation, a widely used test of genotoxicity in mammals, was observed in embryos exposed to 1 to 50 ng/ml BaP. Grossly abnormal test embryos had high incidences of mitotic aberrations and were composed of large numbers of pycnotic, karyolytic, and multinucleated cells. The results from this cytogenetic analysis demonstrate that mitotic inhibition and aberrations are more sensitive indicators of BaP-induced damage than are developmental effects and suggest that cytogenetic analysis be included in the standard 48-hr sea urchin bioassay procedure when testing contaminants suspected of being mutagens. Cytologic-cytogenetic analysis is particularly suited for use with invertebrates and appears to be as sensitive as more laborious and expensive routine cytogenetic methods which involve karyotyping such as the sister chromatid exchange test.

Philip S. Oshida

Papers

Developmental and cytogenetic abnormalities induced in the purple sea urchin by environmental levels of benzo(a)pyrene.

Effects of hexavalent and trivalent chromium on the reproduction of Neanthes arenaceodentata (polychaeta)

Bioaccumulation of chromium and its effects on reproduction in Neanthes arenaceodentata (polychaeta)

Effects of municipal wastewater on fertilization, survival, and development of the sea urchin, strongylocentrotus purpuratus

A simple new bioassay based on echinochrome synthesis by larval sea urchins