Integrating Field Analyses with Laboratory Exposures to Assess Ecosystems Health

Abstract

initiated a programme on the evaluation of the carcinogenic risk of chemicals to humans involving the production of critically evaluated monographs on individual chemicals. The programme was subsequently expanded to include evaluations of carcinogenic risks associated with exposures to complex mixtures, life-style factors and biological and physical agents, as well as those in specific occupations. The objective of the programme is to elaborate and publish in the form of monographs critical reviews of data on carcinogenicity for agents to which humans are known to be exposed and on specific exposure situations; to evaluate these data in terms of human risk with the help of international working groups of experts in chemical carcinogenesis Publications of the World Health Organization enjoy copyright protection in accordance with the provisions of Protocol 2 of the Universal Copyright Convention. All rights reserved.The International Agency for Research on Cancer welcomes requests for permission to reproduce or translate its publications, in part or in full. Requests for permission to reproduce or translate IARC publications -whether for sale or for noncommercial distribution -should be addressed to WHO Press, at the above address (fax: +41 22 791 4806; email: permissions@who.int).The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city, or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.The mention of specific companies or of certain manufacturers' products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters.The IARC Monographs Working Group alone is responsible for the views expressed in this publication. IARC Library Cataloguing in Publication Data NOTE TO THE READERThe term 'carcinogenic risk' in the IARC Monographs series is taken to mean that an agent is capable of causing cancer under some circumstances. The Monographs evaluate cancer hazards, despite the historical presence of the word 'risks' in the title.Inclusion of an agent in the Monographs does not imply that it is a carcinogen, only that the published data have been examined. Equally, the fact that an agent has not yet been evaluated in a Monograph does not mean that it is not carcinogenic.The evaluations of carcinogenic risk are made by international working groups of independent scientists and are qualitative in nature. No recommendation is given for regulation or legislation.Anyone who is aware of published data that may alter the evaluation of the carcinogenic risk of an agent to humans is encouraged to make this information available to the Section of IARC Monographs, International Agency for...

Toxicokinetics and bioaccumulation of polycyclic aromatic compounds in wood frog tadpoles (Lithobates sylvaticus) exposed to Athabasca oil sands sediment

“…To our knowledge, no study concerning the bioaccumulation potential and toxicokinetics of parent and alkyl PACs in amphibian larvae exposed to bitumenrich oil sands sediment and/or water has been undertaken. This would be indispensable in interpreting PAC residues (Hellou et al, 2012); for instance, it would help us determine whether higher PAC body burdens in amphibian larvae are a result of higher levels of exposure or a product of bioaccumulation. Finally, distinguishing which PACs have the greatest bioaccumulation potential will help determine those of greater concern and of greater importance in monitoring.…”

“…During phase I, the compounds are oxidized by the cytochrome P450 monooxygenases to more reactive intermediates (phenols and epoxides). In phase II, biotransformation enzymes transform the intermediates via conjugation into more polar compounds, rendering them more water soluble and amenable to transport out of cells and subsequently, out of the organism (elimination) (Hellou et al, 2012, Shimada, 2006, Manzetti, 2013, van der Oost et al, 2003. With intermediate levels of total cytochrome P450 and inducible cytochrome P4501A activity compared to those of invertebrates and vertebrates of higher trophic levels (e.g., mammals) (Marty et al, 1992, Ertl andWinston, 1998), fish and amphibians are known to metabolize parent PACs (Livingstone, 1998, Berrojalbiz et al, 2009, Garrigues et al, 2004, Gewurtz et al, 2000, Neff, 1979, Ueda et al, 2011.…”

“…Some of these activated phase I metabolites have been linked with PAC toxicity and DNA adduct formation (Incardona et al, 2006, Stowers andAnderson, 1985). During phase II, biotransformation enzymes transform the intermediates via conjugation into more polar compounds, rendering them more water soluble and amenable to transport out of cells and subsequently, out of the organism (elimination) (Hellou et al, 2012, Shimada, 2006, Manzetti, 2013, van der Oost et al, 2003. Phase II is primarily performed by conjugation enzymes such as uridine diphosphate glucuronosyltransferases, sulfotransferases, and glutathione-S-transferase.…”

“…Consequently, organisms residing in the benthic substrate of wetlands may be at higher risk of exposure to PACs. Benthic and epibenthic invertebrates have been the subject of numerous studies on PAC contamination of freshwater ecosystems (Ganshorn, 2002, Gewurtz et al, 2000, Hellou et al, 2012, Wayland et al, 2008, but few studies have considered amphibians (Gupta, 2009, Hersikorn and Smits, 2011, Garrigues et al, 2004, Marquis et al, 2006.…”

“…In particular, polycyclic aromatic compounds (PACs) are of great concern to aquatic biota and ecosystems (Eisler, 1987, Laender et al, 2011, Wu et al, 2011, Ikenaka et al, 2013. Not only are PACs toxic, carcinogenic, and/or mutagenic organic compounds (Sanz-Lazaro et al, 2008, IARC, 1998, OMOE, 1990, but due to their hydrophobicity, some PACs also have a tendency to bioaccumulate in organisms (Hellou et al, 2012, Leppanen, 1999, Schwarzenbach et al, 2003.…”