This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organization or the World Health Organization. Environmental Health Criteria 229 SELECTED NITRO- AND NITRO- OXY-POLYCYCLIC AROMATIC HYDROCARBONS First draft prepared by Drs J. Kielhorn, U. Wahnschaffe and I. Mangelsdorf, Fraunhofer Institute of Toxicology and Aerosol Research, Hanover, Germany Please note that the pagination and layout of this web version are not identical to the printed EHC Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals. The International Programme on Chemical Safety (IPCS), established in 1980, is a joint venture of the United Nations Environment Programme (UNEP), the International Labour Organization (ILO) and the World Health Organization (WHO). The overall objectives of the IPCS are to establish the scientific basis for assessment of the risk to human health and the environment from exposure to chemicals, through international peer review processes, as a prerequisite for the promotion of chemical safety, and to provide technical assistance in strengthening national capacities for the sound management of chemicals. The Inter-Organization Programme for the Sound Management of Chemicals (IOMC) was established in 1995 by UNEP, ILO, the Food and Agriculture Organization of the United Nations, WHO, the United Nations Industrial Development Organization, the United Nations Institute for Training and Research and the Organisation for Economic Co- operation and Development (Participating Organizations), following recommendations made by the 1992 UN Conference on Environment and Development to strengthen cooperation and increase coordination in the field of chemical safety. The purpose of the IOMC is to promote coordination of the policies and activities pursued by the Participating Organizations, jointly or separately, to achieve the sound management of chemicals in relation to human health and the environment. WHO Library Cataloguing-in-Publication Data Selected nitro- and nitro-oxy-polycyclic aromatic hydrocarbons. (Environmental health criteria ; 229) 1.Polycyclic hydrocarbons, Aromatic - toxicity 2.Polycyclic hydrocarbons, Aromatic - adverse effects 3.Environmental exposure 4.Risk assessment I.International Programme for Chemical Safety II.Series ISBN 92 4 157229 9 (NLM classification: QD 341.H9) ISSN 0250-863X The World Health Organization welcomes requests for permission to reproduce or translate its publications, in part or in full. Applications and enquiries should be addressed to the Office of Publications, World Health Organization, Geneva, Switzerland, which will be glad to provide the latest information on any changes made to the text, plans for new editions, and reprints and translations already available. ©World Health Organization 2003 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. 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CONTENTS ENVIRONMENTAL HEALTH CRITERIA FOR SELECTED NITRO- AND NITRO-OXY-POLYCYCLIC AROMATIC HYDROCARBONS PREAMBLE xiii ACRONYMS AND ABBREVIATIONS xxiii 1. SUMMARY 1 1.1 Identity, physical and chemical properties, and analytical methods 1 1.2 Sources of human and environmental exposure 2 1.3 Environmental transport, distribution and transformation 4 1.3.1 Environmental transport and distribution 4 1.3.2 Biotransformation 4 1.3.3 Abiotic degradation 5 1.4 Environmental levels and human exposure 6 1.4.1 Indoor air 7 1.4.2 Food and beverages 7 1.4.3 Other products 8 1.4.4 Occupational exposure 8 1.5 Kinetics and metabolism in laboratory animals and humans 9 1.6 Effects on laboratory mammals and in vitro test systems 10 1.7 Effects on humans 14 1.8 Effects on other organisms in the laboratory and field 14 2. IDENTITY, PHYSICAL AND CHEMICAL PROPERTIES, AND ANALYTICAL METHODS 16 2.1 Identity 16 2.2 Physical and chemical properties 23 2.3 Conversion factors 23 2.4 Analytical methods 30 iii EHC 229: Selected Nitro- and Nitro-oxyPAHs 2.4.1 Sampling 31 2.4.2 Extraction 38 2.4.3 Cleanup 38 2.4.4 Analytical separation and detection 39 2.4.4.1 Difficulties in analysis 42 2.4.4.2 Complex mixtures 43 2.4.4.3 Analysis of nitro-oxyPAHs 43 2.4.5 Use of bioassay (mutagenicity) fractionation and chemical analysis 43 3. SOURCES OF HUMAN AND ENVIRONMENTAL EXPOSURE 47 3.1 Industrially produced nitroPAHs 47 3.1.1 Production levels and processes 47 3.1.2 Uses of commercially produced nitroPAHs 47 3.2 Other sources of nitroPAHs 48 3.2.1 Direct sources of nitroPAHs from combustion processes 54 3.2.1.1 Diesel exhaust 54 3.2.1.2 Diesel compared with gasoline exhaust 62 3.2.1.3 Aeroplane emissions 62 3.2.1.4 Emissions from combustion of heating oils 63 3.2.1.5 Fumes from cooking oils 63 3.2.1.6 Other combustion sources 63 3.2.2 Atmospheric formation of nitroPAHs 64 3.2.2.1 Reactions of gas-phase PAHs (and nitroPAHs) with the hydroxyl radical (daytime reactions) 66 3.2.2.2 Reactions of gas-phase PAHs (and nitroPAHs) with the nitrate radical (nighttime reactions) 68 3.3 Oxygen-containing nitroPAHs 68 4. ENVIRONMENTAL TRANSPORT, DISTRIBUTION AND TRANSFORMATION 70 4.1 Transport and distribution between media 70 4.1.1 Distribution and transport in the atmosphere 70 iv 4.1.1.1 Distribution of nitroPAHs between fine and coarse fractions of inhalable atmospheric particulates 71 4.1.2 Distribution and transport in the hydrosphere 71 4.1.3 Adsorption onto soils and sediments 71 4.1.4 Bioaccumulation 72 4.1.5 Biomagnification 72 4.2 Transformation 72 4.2.1 Biotransformation 72 4.2.1.1 Bacteria 72 4.2.1.2 Fungi 75 4.2.1.3 Plants 75 4.2.1.4 Aquatic animals 76 4.2.2 Abiotic degradation 76 4.2.2.1 Direct photolysis 76 4.2.2.2 Other atmospheric transformations 85 5. ENVIRONMENTAL LEVELS AND HUMAN EXPOSURE 87 5.1 Environmental levels 87 5.1.1 Air 87 5.1.1.1 Ambient air 87 5.1.1.2 Indoor air 107 5.1.2 Water 109 5.1.3 Soil, sewage sludge, sediment and incinerator ash 109 5.1.4 Food and beverages 110 5.1.4.1 Food 110 5.1.4.2 Beverages 114 5.1.5 Other sources 116 5.1.5.1 Carbon black and toners 116 5.1.5.2 Cigarette smoke 116 5.2 General population exposure 116 5.3 Occupational exposure 117 6. KINETICS AND METABOLISM IN LABORATORY ANIMALS AND HUMANS 121 6.1 Overview of the metabolism of nitroPAHs 121 v EHC 229: Selected Nitro- and Nitro-oxyPAHs 6.2 1-Nitropyrene metabolism in mammals 125 6.2.1 Absorption 125 6.2.2 Distribution 125 6.2.3 Metabolism 126 6.2.3.1 Introduction 126 6.2.3.2 Identification of metabolites 126 6.2.3.3 Cytochrome P450-mediated ring C-oxidative pathway 137 6.2.3.4 Nitroreduction pathway 138 6.2.3.5 Human and rodent intestinal microflora 139 6.2.3.6 Suggested metabolic pathway 140 6.2.4 Elimination and excretion 141 6.2.4.1 Elimination 141 6.2.4.2 Excretion 142 6.2.4.3 Biliary excretion and enterohepatic circulation 142 6.2.5 Reaction with body components 142 6.2.5.1 Protein binding 143 6.2.5.2 DNA adducts 143 6.2.6 Biomonitoring studies 151 6.3 Mononitropyrenes (1-, 2- and 4-nitropyrene) — a comparison 152 6.3.1 Faecal and urinary excretion 152 6.3.2 Metabolism 152 6.3.3 DNA adducts 154 6.4 2-Nitrofluorene 155 6.4.1 Absorption, distribution and elimination 155 6.4.2 Metabolism/mechanism of action 158 6.4.2.1 Metabolites 158 6.4.2.2 DNA adducts 160 6.4.2.3 Haemoglobin adducts 161 6.5 Dinitropyrenes (1,3-, 1,6- and 1,8-dinitropyrene) 161 6.6 Mononitrobenzo[a]pyrenes (1-, 3- and 6-nitrobenzo[a]pyrene) 164 6.7 The nitrofluoranthene family 165 6.8 2- and 9-nitroanthracene 167 6.9 6-Nitrochrysene 168 6.10 K- and H-ras mutations in tumours produced by nitroPAHs 170 vi 6.11 Human enzymes expected to be involved in nitroPAH metabolism 171 7. EFFECTS ON LABORATORY MAMMALS AND IN VITRO TEST SYSTEMS 172 7.1 Acute toxicity 172 7.1.1 1-Nitronaphthalene 172 7.1.2 2-Nitronaphthalene 173 7.1.3 5-Nitroacenaphthene 173 7.1.4 2-Nitrofluorene 173 7.1.5 3,9-Dinitrofluoranthene 173 7.1.6 1-Nitropyrene 173 7.2 Short-term and long-term exposure (non- neoplastic effects) 174 7.2.1 1-Nitronaphthalene 174 7.2.2 5-Nitroacenaphthene 174 7.2.3 2-Nitrofluorene 219 7.2.4 1-Nitropyrene 219 7.2.5 1,3-Dinitropyrene 220 7.2.6 1,6-Dinitropyrene 220 7.2.7 1,8-Dinitropyrene 220 7.2.8 6-Nitrochrysene 220 7.2.9 1- and 3-nitrobenzo[a]pyrene 220 7.2.10 1,6-Dinitrobenzo[a]pyrene 221 7.3 Skin and eye irritation and sensitization 221 7.4 Reproductive toxicity, embryotoxicity and teratogenicity 221 7.5 Mutagenicity and related end-points 221 7.5.1 In vitro genotoxicity studies 237 7.5.1.1 Salmonella typhimurium microsome assay 237 7.5.1.2 Comparison of the mutagenic potency of nitroPAHs in the Salmonella microsome assay 293 7.5.1.3 Studies into the pathways of microbial metabolism 294 7.5.1.4 Relationship between mutagenic potency in S.