Rapport Subtiltle r gional Ð opportunit s et d fis ˆ l'horizon 2020

Transcription

1 Biotecnología Etude Title Spanish prospective agrícola para du gdfgdfgdf secteur países sd forestier en desarrollo Resultados en JgfsdFFAO/WHO Afrique de un foro electrónico Meetingf ISSN ISSN X ISSN ESTUDIO ƒtude FAO INVESTIGACIÓN PRODUCCIîN FORæTS Y TECNOLOGIA Y SANIDAD ANIMAL Rapport Subtiltle r gional Ð opportunit s et d fis ˆ l'horizon

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3 FAO PLANT PRODUCTION AND PROTECTION PAPER Report of the special session of the Joint Meeting of the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Core Assessment Group on Pesticide Residues Geneva, Switzerland, 9 13 May 2016 WORLD HEALTH ORGANIZATION FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2016

4 The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) or of the World Health Organization (WHO) concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these are or have been endorsed or recommended by FAO or WHO 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. All reasonable precautions have been taken by FAO and WHO to verify the information contained in this publication. However, the published material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall FAO and WHO be liable for damages arising from its use. The views expressed herein are those of the authors and do not necessarily represent those of FAO or WHO. ISBN FAO and WHO, 2016 FAO and WHO encourage the use, reproduction and dissemination of material in this information product. Except where otherwise indicated, material may be copied, downloaded and printed for private study, research and teaching purposes, provided that appropriate acknowledgement of FAO and WHO as the source and copyright holder is given and that FAO and WHO s endorsement of users views, products or services is not implied in any way. All requests for translation and adaptation rights, and for resale and other commercial use rights should be made via or addressed to copyright@fao.org. FAO information products are available on the FAO website ( and can be purchased through publications-sales@fao.org

5 iii TABLE OF CONTENTS List of participants... v Abbreviations... vii Use of JMPR reports and evaluations by registration authorities... ix 1. Introduction Declaration of interests General considerations General considerations on the evaluation of genotoxicity studies Methods for the evaluation of epidemiological evidence for risk assessment Evaluation of data for acceptable daily and acute reference dose for humans Diazinon (22) (T)** Glyphosate (158) (T)** Malathion (49) (T)** Recommendations Annex 1: Acceptable daily s and acute reference doses recorded by the May 2016 Meeting Annex 2: Index of reports and evaluations of pesticides by the JMPR Annex 3: International estimated daily s of pesticide residues Annex 4: International estimates of short-term ary s of pesticide residues Annex 5: Reports and other documents resulting from previous Joint Meetings of the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Core Assessment Group on Pesticide Residues T, toxicological evaluation ** Evaluated following the recommendation of an electronic task force of the WHO Core Assessment Group on Pesticide Residues that the compound be re-evaluated due to public health concerns identified by IARC and the availability of a significant number of new studies

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7 v LIST OF PARTICIPANTS 2016 Joint FAO/WHO Meeting on Pesticide Residues Geneva, 9 13 May 2016 Professor Alan R. Boobis, Centre for Pharmacology & Therapeutics, Division of Experimental Medicine, Department of Medicine, Faculty of Medicine, Imperial College London, Hammersmith Campus, Ducane Road, London W12 0NN, United Kingdom (WHO Chairman) Ms Marloes Busschers, Assessor of Human Toxicology, Board for the Authorisation of Plant Protection Products and Biocides, Bennekomseweg 41, 6717 LL Ede, PO Box 2030, 6710 AA Ede, the Netherlands (WHO Expert) Dr Carl E. Cerniglia, 1 Director, Division of Microbiology, National Center for Toxicological Research, HFT-250, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, United States of America (USA) (WHO Expert) Dr Sylvaine Cordier, 2 Research Director Emeritus, French National Institute of Health and Medical Research (INSERM U1085), University of Rennes, 2 rue de Tabor, CS 46510, Rennes, France (WHO Expert) Dr David Eastmond, Department of Cell Biology & Neuroscience, 2109 Biological Sciences Building, University of California, Riverside, CA 92521, USA (WHO Expert) Professor Dr Andrea Hartwig, 3 Karlsruher Institut für Technologie, Institut für Angewandte Biowissenschaften, Abteilung Lebensmittelchemie und Toxicologie, Adenauerring 20a, Gebäude (AVG), Raum 103, Postanschrift: Kaiserstr. 12, Karlsruhe, Germany (WHO Expert) Dr Miriam Jacobs, Toxicology Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Oxfordshire, OX11 0RQ, United Kingdom (WHO Expert) Dr Virissa Lenters (assisting), 1 Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, PO Box 80178, Utrecht, the Netherlands (WHO Expert) Dr Dugald MacLachlan, Australian Government Department of Agriculture and Water Resources, GPO Box 858, Canberra, ACT 2601, Australia (FAO Chairman) Professor Angelo Moretto, Department of Biomedical and Clinical Sciences, University of Milan, International Centre for Pesticides and Health Risk Prevention (ICPS), ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Via GB Grassi 74, Milano, Italy (Rapporteur) Dr Matthew Joseph O Mullane, Director, Chemical Review, Australian Pesticides and Veterinary Medicines Authority (APVMA), PO Box 6182, Kingston, ACT 2604, Australia (WHO Expert) Dr Aldert H. Piersma, Professor of Reproductive and Developmental Toxicology, Center for Health Protection, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, PO Box 1, 3720 BA Bilthoven, the Netherlands (WHO Expert) 1 Did not attend the meeting. 2 Did not attend the meeting, but her valuable contributions to the methodological setup of the epidemiological evaluation are gratefully acknowledged. 3 Attended part of the meeting only.

8 vi Dr Prakashchandra V. Shah, Chief, Chemistry, Inerts and Toxicology Assessment Branch, Registration Division (MDTS 7505P), Office of Pesticide Programs, United States Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460, USA (WHO Expert) Dr Rachel B. Smith (assisting), 1 Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, Norfolk Place, London W2 1PG, United Kingdom (WHO Expert) Dr Raymond Tice, Special Volunteer, Biomolecular Screening Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Mail Code K2-17, PO Box 12233, Research Triangle Park, NC 27709, USA (WHO Expert) Dr Mireille B. Toledano, Senior Lecturer in Epidemiology, MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, Imperial College London, St Mary s Campus, Norfolk Place, London W2 1PG, United Kingdom (WHO Expert) Dr Midori Yoshida, Commissioner, Food Safety Commission, Cabinet Office, Akasaka Park Building, 22nd Floor, Akasaka Minato-ku, Tokyo , Japan (WHO Expert) Dr Jürg Zarn, Federal Food Safety and Veterinary Office (FSVO), Risk Assessment Division, Schwarzenburgstrasse 155, CH-3003 Bern, Switzerland (WHO Expert) Secretariat Mr Enzo Armaroli, Intern, Department of Food Safety and Zoonoses, World Health Organization, 1211 Geneva 27, Switzerland Dr Richard Brown, Evidence and Policy on Environmental Health, World Health Organization, 1211 Geneva 27, Switzerland Mr Paul Garwood, Department of Communication, World Health Organization, 1211 Geneva 27, Switzerland Dr Kathryn Guyton, International Agency for Research on Cancer, 150 Cours Albert Thomas, Lyon, France Ms Marla Sheffer, 1553 Marcoux Drive, Orleans, Ontario, Canada K1E 2K5 (WHO Editor) Dr Angelika Tritscher, Coordinator, Risk Assessment and Management, Department of Food Safety and Zoonoses, World Health Organization, 1211 Geneva 27, Switzerland Dr Philippe Verger, Department of Food Safety and Zoonoses, World Health Organization, 1211 Geneva 27, Switzerland (WHO JMPR Secretary) Ms Yong Zhen Yang, Plant Production and Protection Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, Rome, Italy (FAO JMPR Secretary) 1 Did not attend the meeting.

9 vii ABBREVIATIONS ADI AHS AMPA ARfD BMD bw CAS CCPR CI CYP DCF DNA F 0 F 1 FAO GEMS/Food GLP HR HR-P IARC IEDI IESTI ISO IUPAC JMPR LC 50 LD 50 LOAEL MDCA MIC MMCA MRL NC acceptable daily Agricultural Health Study aminomethylphosphonic acid acute reference dose benchmark dose body weight Chemical Abstracts Service Codex Committee on Pesticide Residues confidence interval cytochrome P450 correction factor deoxyribonucleic acid parental generation first filial generation Food and Agriculture Organization of the United Nations Global Environment Monitoring System Food Contamination Monitoring and Assessment Programme good laboratory practice highest residue in the edible portion of a commodity found in trials used to estimate a maximum residue level in the commodity highest residue in a processed commodity calculated by multiplying the HR of the raw commodity by the corresponding processing factor International Agency for Research on Cancer international estimated daily international estimate of short-term ary International Organization for Standardization International Union of Pure and Applied Chemistry Joint FAO/WHO Meeting on Pesticide Residues median lethal concentration median lethal dose lowest-observed-adverse-effect level malathion dicarboxylic acid minimum inhibitory concentration malathion monocarboxylic acid maximum residue limit no national consumption data available

10 viii NES NHL NOAEC NOAEL OR PP ppm RAC RR STMR STMR-P TAF WHO not elsewhere specified non-hodgkin lymphoma no-observed-adverse-effect concentration no-observed-adverse-effect level odds ratio processed product parts per million raw agricultural commodity relative risk supervised trials median residue supervised trials median residue in a processed commodity calculated by multiplying the STMR of the raw commodity by the corresponding processing factor toxicity adjustment factor World Health Organization

11 ix USE OF JMPR REPORTS AND EVALUATIONS BY REGISTRATION AUTHORITIES Most of the summaries and evaluations contained in this report are based on unpublished proprietary data submitted for use by JMPR in making its assessments. A registration authority should not grant a registration on the basis of an evaluation unless it has first received authorization for such use from the owner of the data submitted for the JMPR review or has received the data on which the summaries are based, either from the owner of the data or from a second party that has obtained permission from the owner of the data for this purpose.

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13 Introduction 1 PESTICIDE RESIDUES IN FOOD REPORT OF THE MAY 2016 JOINT FAO/WHO MEETING OF EXPERTS 1. INTRODUCTION A Joint Meeting of the Food and Agriculture Organization of the United Nations (FAO) Panel of Experts on Pesticide Residues in Food and the Environment and the World Health Organization (WHO) Core Assessment Group on Pesticide Residues (JMPR) was held at WHO Headquarters, Geneva (Switzerland), from 9 to 13 May The meeting was opened by Dr Kazuaki Miyagishima, Director of the Department of Food Safety and Zoonoses, WHO, who welcomed participants on behalf of the Directors General of WHO and FAO. Dr Miyagishima stated that the meeting was convened to re-evaluate three compounds for which new studies had become available since their last full assessments. He reminded the participants of the importance of the functional separation between risk assessment and risk management and of the role that JMPR plays as the expert risk assessment body providing scientific advice to Codex and to Member States. He urged the participants to be guided by JMPR s standing rules and procedures based on the weight of evidence approach. Dr Miyagishima thanked the participants for devoting significant time and effort to the work of JMPR, including the preparatory work of paramount importance that had taken place in the past months. He reminded the experts that they were invited as independent experts acting in their own individual capacities and not as representatives of their countries or organizations. He also reminded the participants of the confidential nature of the meeting, in order to allow experts to freely express their opinions. During the meeting, the WHO Core Assessment Group was responsible for reviewing epidemiological, toxicological and related data in order to establish acceptable daily s (ADIs) and acute reference doses (ARfDs), where necessary. As no residue data were requested, the FAO Expert was responsible for estimating the ary exposures (both short-term and long-term) to the pesticides reviewed and, on this basis, performed ary risk assessments in relation to their ADIs or ARfDs. The Meeting re-evaluated three pesticides, established ADIs and ARfDs and recommended them for use by the Codex Committee on Pesticide Residues (CCPR). The Meeting also considered issues related to the evaluation of genotoxicity and epidemiological studies in relation to the risk assessment of chemicals. 1.1 DECLARATION OF INTERESTS The Secretariat informed the Meeting that all experts participating in the May 2016 JMPR had completed declaration of interest forms and that no conflicts had been identified.

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15 General considerations 3 2. GENERAL CONSIDERATIONS 2.1 GENERAL CONSIDERATIONS ON THE EVALUATION OF GENOTOXICITY STUDIES A large number of genotoxicity studies were evaluated during the present meeting. These were identified through direct submission to JMPR, searches of the publicly available literature and requests to the International Agency for Research on Cancer (IARC) Monographs Secretariat and industry groups. The studies evaluated included unpublished (primarily guideline) studies submitted to support pesticide registration as well as peer-reviewed studies published in the scientific literature. The number, quality and relevance of studies differed widely for each chemical and necessitated that a somewhat different approach be used to evaluate each pesticide. As a general strategy, the studies were separated into categories based largely on phylogenetic relevance and significance of the genetic end-point measured. The categories used were human biomonitoring, in vivo mammals, in vitro mammalian cells, in vitro bacteria, phylogenetically distant organisms, metabolites in vivo and metabolites in vitro. The evaluation was conducted for the pesticide active ingredient, its formulation products and prominent metabolites, as data were available. For the three pesticides evaluated, the human biomonitoring studies were most often confounded by exposures to other pesticides or considered to have other limitations. Among the genotoxicity studies, in vivo studies in mammals were given the greatest weight, compared with cell culture studies or investigations in phylogenetically distant organisms. Studies of gene mutations and chromosomal alterations were also given more weight than studies measuring other less serious or transient types of genotoxic damage. With regard to route of exposure, studies in which chemicals were administered by the oral route were considered to be of most relevance for evaluating low-level ary exposures. Following an evaluation and weighting of the studies, taking the criteria described above and the quality of the studies into account, an overall weight of evidence approach was used to reach conclusions about the genotoxicity of the individual pesticides. An important aspect of the evaluation was whether the genotoxic effect would be likely to occur in humans exposed to low levels of the pesticide present as residues in food. The Meeting recommended that a guidance document be developed for the evaluation of genotoxicity studies, taking the experience gained from this meeting into account. 2.2 METHODS FOR THE EVALUATION OF EPIDEMIOLOGICAL EVIDENCE FOR RISK ASSESSMENT Identification of compound/cancer sites and screening of papers There is a large body of literature regarding pesticide exposures and non-cancer outcomes (neurodevelopmental, neurodegenerative and reproductive outcomes, among other health outcomes), but the assessment of the epidemiological evidence on diazinon, glyphosate and malathion was restricted to studies of cancer outcomes. This restriction was partly driven by feasibility reasons: a clinically relevant adverse effect size (or an acceptable level of risk) for a non-cancer outcome must be defined, and the methodologies for hazard identification and characterization based on observational epidemiological findings of non-carcinogenic adverse effects are less well established than those for cancer. 1 1 See, for example, Clewell HJ, Crump KS. Quantitative estimates of risk for noncancer endpoints. Risk Anal. 2005;25(2):285 9; and Nachman KE, Fox MA, Sheehan MC, Burke TA, Rodricks JV, Woodruff TJ. Leveraging epidemiology to improve risk assessment. Open Epidemiol J. 2011;4:3 29.

16 4 General considerations The IARC Monographs on malathion, diazinon and glyphosate referred to a total of 45 epidemiological studies. 1 Databases were searched for any relevant articles published after the studies cited in these Monographs using the following search terms: [(diazinon OR glyphosate OR malathion) AND cancer] and [(diazinon OR glyphosate OR malathion) AND (NHL OR lymphoma OR leukemia OR lung cancer OR prostate cancer )] in PubMed (limited to Humans; published in the last 5 years) and Scopus (limited to ). Two studies published since the publication of the IARC Monographs that evaluated at least one of malathion, diazinon or glyphosate were identified in relation to cancer outcomes. 2 An additional study on prostate cancer, 3 which was not included in the IARC Monographs, was also identified. The pre-agreed evaluation process shown in Fig. 1 was used to (1) select compound/cancer site combinations to include in this evaluation; (2) screen papers for inclusion/exclusion in this evaluation (Tier 1 screening criteria); and (3) evaluate the information available for risk assessment. In this process, it was noted that there were stand-alone analyses for specific subtypes of non- Hodgkin lymphoma (NHL). The risk for subtypes of NHL was not evaluated separately, as there was insufficient evidence (too few studies or small numbers of cases); the risk for other haematopoietic and lymphoid tumours was also not evaluated separately, as the positive associations identified by IARC were for total NHL. 1. Relevance - For each compound/cancer site combination - did IARC identify positive associations from the body of epidemiological evidence? Yes 6 compound/cancer site combinations Exclude compound /cancer site combination from evaluation ACTION - for each relevant compound/cancer site: Identify all papers in IARC Monographs assessing relevant compound/cancer sites (positive and null associations) Identify any papers published since IARC Monograph which address relevant compound/cancer site Search by hand (e.g. check reference lists of identified papers) for any papers potentially missed No Figure 1: Evaluation process for epidemiological evidence The current effort is restricted cancer outcomes 26 papers identified 2. For related papers that examined the same compound/cancer site is this: - the most recent publication with longest follow-up for this compound/cancer site? (e.g. cohort studies) - the most complete and updated analysis with the greatest number of participants for this compound/cancer site? (e.g. pooled case-control) No Exclude paper from evaluation for given compound/cancer site Malathion/NHL 2 papers excluded Diazinon/NHL 2 papers excluded Diazinon/Lung 2 papers excluded Glyphosate/NHL 2 papers excluded Tier 1 screening criteria Yes 3. Is exposure assessment specific to compound of interest? No Paper is not relevant to risk assessment for compound Diazinon/NHL 1 paper excluded Yes 4. Quantitative exposure assessment (exposure expressed on a ratio scale) Yes No Paper is relevant but cannot contribute information to a quantitative risk assessment Paper is relevant and can contribute to quantitative risk assessment (i.e. hazard characterization) for compound/cancer site ACTIONS - for each relevant paper: Extract information on quantitative exposure units. Describe magnitude of effect/uncertainty Review quality of study based on IARC Monograph and evaluation criteria. Describe exposure assessment and how exposure levels compare to/translate to pesticide residue levels/pathways. Overall summary ACTIONS for each compound/cancer site: Characterize hazard for each compound/cancer site from all studies contributing to quantitative risk assessment, e.g. forest plot (or metaregression, time-permitting). Summarize strength of evidence. 1 IARC. Some organophosphate insecticides and herbicides: tetrachlorvinphos, parathion, malathion, diazinon and glyphosate. Lyon: International Agency for Research on Cancer; 2015 (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 112). 2 Koutros S, Silverman DT, Alavanja MC, Andreotti G, Lerro CC, Heltshe S et al. Occupational exposure to pesticides and bladder cancer risk. Int J Epidemiol. 2015; pii: dyv195 [Epub ahead of print]; and Lerro CC, Koutros S, Andreotti G, Friesen MC, Alavanja MC, Blair A et al. Organophosphate insecticide use and cancer incidence among spouses of pesticide applicators in the Agricultural Health Study. Occup Environ Med. 2015; 72(10): Mills PK, Yang R. Prostate cancer risk in California farm workers. J Occup Environ Med. 2003; 45(3):

17 General considerations 5 Evaluation of evidence for the compound/cancer site associations Several aspects of each study and of all studies combined were considered in this evaluation, including factors that decrease the level of confidence in the body of evidence, such as risk of bias, unexplained inconsistency and imprecision; and factors that increase the level of confidence, such as large magnitude of effect, dose-response and consistency. 1 The findings for each study were summarized in tables, and risk estimates for non-quantitative exposure assessment (predominantly ever versus never use) were summarized in forest plots. Evaluation of information available for risk assessment/hazard characterization To evaluate overall evidence for dose-response relationships, risk estimates were plotted against quantitative exposure measures (for studies that had used these). The most commonly used quantitative exposure metric was days of use per year. Where studies had used other quantitative exposure metrics (e.g. lifetime days of exposure), data were requested from the authors on median days of use per year for the participants in each of the original exposure categories, although this information was not always forthcoming. These additional data allowed the translation and plotting of risk estimates from different studies on the same exposure scale (days of use per year). 1 Guyatt GH, Oxman AD, Vist GE, Kunz R, Falck-Ytter Y, Alonso-Coello P et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008;336:924-6; and Morgan RL, Thayer KA, Bero L, Bruce N, Falck-Ytter Y, Ghersi D et al. GRADE: Assessing the quality of evidence in environmental and occupational health. Environ Int. 2016;doi: /j.envint [Epub ahead of print].

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19 Diazinon 7 3. EVALUATION OF DATA FOR ACCEPTABLE DAILY INTAKE AND ACUTE REFERENCE DOSE FOR HUMANS 3.1 DIAZINON (22) TOXICOLOGY Diazinon is the common name approved by the International Organization for Standardization (ISO) for O,O-hyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate (International Union of Pure and Applied Chemistry [IUPAC]), with the Chemical Abstracts Service (CAS) number Diazinon is a contact organophosphorus insecticide with a wide range of insecticidal activity. It is effective against adult and juvenile forms of flying insects, crawling insects, acarians and spiders. Diazoxon, the biologically active metabolite of diazinon, inhibits the activity of cholinesterases. Diazinon is used mainly as a pesticide in agriculture and as a drug in veterinary medicine. Thus, the major source of diazinon residues in edible crops is from its use as an agricultural pesticide; residues in meat, offal and other animal products arise from its use as a veterinary drug containing active ingredient. Diazinon has been evaluated by JMPR on several occasions since the first evaluation in In the most recent evaluation, in 2006, the Meeting established an ADI of mg/kg body weight (bw), based on a no-observed-adverse-effect level (NOAEL) of 0.5 mg/kg bw per day for inhibition of erythrocyte acetylcholinesterase activity in a 92-day repeated-dose toxicity study in rats. The 2006 Meeting reaffirmed the ARfD of 0.03 mg/kg bw, established by the 2001 JMPR, based on a NOAEL of 2.5 mg/kg bw observed in a study of acute neurotoxicity in rats. Diazinon was scheduled within the periodic review programme of CCPR for The compound was placed on the agenda by the JMPR Secretariat following the recommendation of an electronic task force of the WHO Core Assessment Group on Pesticide Residues that it be reevaluated due to public health concerns identified by IARC and the availability of a significant number of new studies. The current Meeting evaluated all previously considered toxicological data in addition to new published or unpublished toxicological studies and published epidemiological studies on cancer outcomes. Several study reports evaluated at previous JMPR meetings were not available to the present Meeting, as they were not submitted in the sponsor s dossier; for these studies, the evaluations in this report were summarized from the 1993 JMPR monograph without further review. All critical unpublished studies contained statements of compliance with good laboratory practice (GLP), unless otherwise specified. The studies on human volunteers were conducted in accordance with the principles expressed in the Declaration of Helsinki or equivalent ethical standards. Biochemical aspects Following oral administration to rats, diazinon was almost completely absorbed and rapidly eliminated, mainly in the urine. There was no evidence of accumulation. Diazinon is metabolized by P450 to diazoxon, the active metabolite. The main degradative pathway includes the oxidase/hydrolase-mediated cleavage of the ester bond, leading to the pyrimidinol derivative 2-isopropyl-6-methyl-4(1H)-pyrimidinone, which is further oxidized to more polar metabolites.

20 8 Diazinon Toxicological data The oral median lethal dose (LD 50) for diazinon in rats ranged from 300 to greater than 2150 mg/kg bw, whereas the dermal LD 50 was greater than 2000 mg/kg bw. The inhalation median lethal concentration (LC 50) was 3.1 mg/l in rats. Diazinon produced mild skin and eye irritation in rabbits. It caused skin sensitization in the guinea-pig Magnusson and Kligman maximization test. The most sensitive end-point observed in all species given single and repeated doses of diazinon was inhibition of cholinesterase activity. Brain acetylcholinesterase activity was generally decreased at doses higher than those that inhibited erythrocyte acetylcholinesterase activity. Clinical signs of cholinergic toxicity occurred at doses causing more than 50% inhibition of brain acetylcholinesterase activity. Female rats were more sensitive than male rats. Many repeated-dose toxicity studies are available. In both rats and dogs, no effects other than those related to cholinesterase inhibition have been observed at the lowest-observed-adverse-effect level (LOAEL); in general, effects observed at the highest doses can be considered secondary to the cholinergic toxicity. In these studies, NOAELs ranged from 0.02 to 0.5 mg/kg bw per day, and LOAELs ranged from 1 to 15 mg/kg bw per day, based on erythrocyte acetylcholinesterase inhibition (i.e. > 20%), with brain acetylcholinesterase inhibition (i.e. > 10%) generally appearing at the next higher dose and clinical cholinergic signs appearing at doses above 23 mg/kg bw per day. In a 28-day acetylcholinesterase inhibition study, rats received diazinon by ary administration at a concentration of 0, 0.3, 30, 300 or 3000 parts per million (ppm) (equal to 0, 0.02, 2.3, 23 and 213 mg/kg bw per day for males and 0, 0.02, 2.4, 23 and 210 mg/kg bw per day for females, respectively). The NOAEL was 0.3 ppm (equal to 0.02 mg/kg bw per day), on the basis of inhibition of erythrocyte acetylcholinesterase activity at 30 ppm (equal to 2.3 mg/kg bw per day). In a short-term toxicity study, rats were fed diazinon at a concentration of 0 or 2 ppm (equivalent to 0 and 0.2 mg/kg bw per day, respectively) for 7 days or at a concentration of 0 or 25 ppm (equivalent to 0 and 2.5 mg/kg bw per day, respectively) for 30 days. The NOAEL was 2 ppm (equivalent to 0.2 mg/kg bw per day), based on inhibition of erythrocyte acetylcholinesterase activity at 25 ppm (equivalent to 2.5 mg/kg bw per day). In a 3-month toxicity study, rats were given s containing diazinon at a concentration of 0, 0.5, 5, 250 or 2500 ppm (equal to 0, 0.03, 0.3, 15 and 168 mg/kg bw per day for males and 0, 0.04, 0.4, 19 and 212 mg/kg bw per day for females, respectively). The NOAEL was 5 ppm (equal to 0.3 mg/kg bw per day), on the basis of inhibition of erythrocyte and brain acetylcholinesterase activities at 250 ppm (equal to 15 mg/kg bw per day). In a second 3-month toxicity study, rats were fed s containing diazinon at a concentration of 0, 0.3, 30, 300 or 3000 ppm (equal to 0, 0.017, 1.7, 17 and 177 mg/kg bw per day for males and 0, 0.019, 1.9, 19 and 196 mg/kg bw per day for females, respectively). The NOAEL was 0.3 ppm (equal to mg/kg bw per day), on the basis of inhibition of erythrocyte acetylcholinesterase activity at 30 ppm (equal to 1.7 mg/kg bw per day). In a third 3-month toxicity study, female rats were fed s containing diazinon at a concentration of 0, 5, 10 or 15 ppm (equivalent to 0, 0.5, 1 and 1.5 mg/kg bw per day, respectively) for 92 days. In the second phase, female rats were fed s containing diazinon at a concentration of 0, 1, 2, 3 or 4 ppm (equivalent to 0, 0.1, 0.2, 0.3 and 0.4 mg/kg bw per day, respectively) for 42 days. In the third phase, female rats were fed s containing diazinon at a concentration of 0, 0.1, 0.5, 1 or 2 ppm (equivalent to 0, 0.01, 0.05, 0.1 and 0.2 mg/kg bw per day, respectively) for 35 days. The NOAEL in the first phase was 5 ppm (equivalent to 0.5 mg/kg bw per day), based on inhibition of erythrocyte acetylcholinesterase activity at 10 ppm (equivalent to 1 mg/kg bw per day) after dosing for 92 days. The NOAEL for females in the second and third phases were the highest tested doses of 4 ppm (equivalent to 0.4 mg/kg bw per day) and 2 ppm (equivalent to 0.2 mg/kg bw per day) after dosing for 42 and 35 days, respectively.

21 Diazinon 9 In a fourth 3-month toxicity study, rats were fed s containing diazinon at a concentration of 0, 5, 125 or 2000 ppm (equal to 0, 0.3, 7.8 and 198 mg/kg bw per day for males and 0, 0.3, 8.9 and 247 mg/kg bw per day for females, respectively). The NOAEL was 5 ppm (equal to 0.3 mg/kg bw per day), on the basis of inhibition of erythrocyte acetylcholinesterase activity at 125 ppm (equal to 7.8 mg/kg bw per day). In a 90-day repeated-dose neurotoxicity study, rats were dosed in the at 0, 25, 125 or 1000 ppm (equal to 0, 1.7, 8.4 and 69.1 mg/kg bw per day for males and 0, 1.8, 9.3 and 82.4 mg/kg bw per day for females, respectively). A NOAEL could not be identified, as erythrocyte acetylcholinesterase activity was inhibited at 1.7 mg/kg bw per day, the lowest dose tested. In considering the NOAELs and LOAELs identified in the 28-day and 3-month (neuro)toxicity studies in rats measuring the inhibition of acetylcholinesterase activity, the Meeting concluded that the extent of acetylcholinesterase inhibition was not dependent on duration of dosing once steady state had been achieved (within 4 weeks). The overall NOAEL for the 28-day and 3- month (neuro)toxicity studies in rats was 5 ppm, based on inhibition of erythrocyte acetylcholinesterase activity at the overall LOAEL of 10 ppm. In studies where feed consumption data were used to calculate test substance, 5 ppm was equal to 0.3 mg/kg bw per day. These substance data are considered to be more accurate than those calculated using a default conversion factor, in which the NOAEL of 5 ppm is equivalent to 0.5 mg/kg bw per day. In a 90-day toxicity study, dogs were given s containing diazinon at a concentration of 0, 0.1, 0.5, 150 or 300 ppm (equal to 0, , 0.020, 5.9 and 10.9 mg/kg bw per day for males and 0, , 0.021, 5.6 and 11.6 mg/kg bw per day for females, respectively). The NOAEL was 0.5 ppm (equal to mg/kg bw per day), on the basis of inhibition of erythrocyte and brain acetylcholinesterase activities at a ary concentration of 150 ppm (equal to 5.6 mg/kg bw per day). In a second 90-day toxicity study, dogs were given diazinon at 0, 0.3, 3 or 10 mg/kg bw per day by gelatine capsule. The NOAEL was 0.3 mg/kg bw per day, on the basis of inhibition of erythrocyte and brain acetylcholinesterase activities at 3 mg/kg bw per day. In a 1-year toxicity study in dogs given diazinon in the at a concentration of 0, 0.1, 0.5, 150 or 300 ppm (equal to 0, , 0.015, 4.7 and 7.7 mg/kg bw per day for males and 0, , 0.020, 4.5 and 9.1 mg/kg bw per day for females, respectively), the NOAEL was 0.5 ppm (equal to mg/kg bw per day), on the basis of inhibition of erythrocyte (males and females) and brain (females only) acetylcholinesterase activities at 150 ppm (equal to 4.5 mg/kg bw per day). The overall NOAEL for the 90-day and 1-year toxicity studies in dogs was 0.3 mg/kg bw per day, based on inhibition of erythrocyte and brain acetylcholinesterase activities at 3 mg/kg bw per day. In a pre-glp carcinogenicity study in mice that was considered adequate to evaluate carcinogenicity but not chronic toxicity, diazinon was administered at a ary concentration of 0, 100 or 200 ppm (equivalent to 0, 15 and 30 mg/kg bw per day, respectively) over 103 weeks. No treatment-related tumours were observed. In another pre-glp carcinogenicity study in mice, diazinon was administered at a ary concentration of 0, 100, 200, 300 (males) or 400 (females) ppm (equal to 0, 16, 31 and 46 mg/kg bw per day for males and 0, 22, 43 and 86 mg/kg bw per day for females, respectively) for 104 weeks. Cholinesterase activity was not measured in this study. The NOAEL for chronic toxicity was 200 ppm (equal to 31 mg/kg bw per day), based on depression of body weight and lower feed consumption at 300 ppm (equal to 46 mg/kg bw per day). No treatment-related tumours were observed. In a pre-glp carcinogenicity study in rats that was considered adequate to evaluate carcinogenicity but not chronic toxicity, diazinon was administered at a ary concentration of 0, 400 or 800 ppm (equivalent to 0, 20 and 40 mg/kg bw per day, respectively) over 103 weeks. No treatment-related tumours were observed.

22 10 Diazinon In a chronic toxicity study, rats received diazinon in the at a concentration of 0 (untreated and vehicle controls), 0.1, 1.5, 125 or 250 ppm (equal to 0, 0.004, 0.06, 5 and 10 mg/kg bw per day for males and 0, 0.005, 0.07, 6 and 12 mg/kg bw per day for females, respectively) for 98/99 weeks. The NOAEL was 1.5 ppm (equal to 0.06 mg/kg bw per day), on the basis of inhibition of erythrocyte and brain acetylcholinesterase activities at 125 ppm (equal to 5 mg/kg bw per day). From the available data, there was no evidence of a tumorigenic response; however, the group size (N = 20) was too small to allow a conclusion to be reached on carcinogenicity. In a combined chronic toxicity and carcinogenicity study in rats, diazinon was fed in the at concentrations adjusted to achieve target concentrations of 0, 0.025, 0.1, 1.5 and 22.5 mg/kg bw per day for 104 weeks. The NOAEL for long-term toxicity was 0.1 mg/kg bw per day, based on inhibition of erythrocyte acetylcholinesterase activity at 1.5 mg/kg bw per day. No treatment-related tumours were observed. The overall NOAEL for chronic toxicity in rats was 0.1 mg/kg bw per day, based on inhibition of erythrocyte acetylcholinesterase activity at 1.5 mg/kg bw per day. The Meeting concluded that diazinon is not carcinogenic in mice or rats. Given the similarity of the sensitivities of mammalian species, an overall NOAEL in all studies of repeated-dose (neuro)toxicity in rats and dogs could be identified. The overall NOAEL was 0.3 mg/kg bw per day, on the basis of inhibition of acetylcholinesterase activity in erythrocytes at 1 mg/kg bw per day. In studies submitted by the sponsors, diazinon was tested for genotoxicity in an adequate range of assays, both in vitro and in vivo. In addition, many studies with diazinon were described in the published literature, but most of these were considered by the Meeting as inappropriate to evaluate the genotoxicity of diazinon, as they had major deficiencies in study design or reliability (e.g. lack of statistical analysis, testing of mixtures of diazinon with other chemicals and similarity between negative and positive control values). Overall, these studies provided no convincing evidence of genotoxic effects. The Meeting concluded that diazinon is unlikely to be genotoxic. In the multigeneration and developmental toxicity studies, cholinesterase activity was not measured. In a two-generation study on reproductive toxicity, rats received diazinon in the at a concentration of 0, 10, 100 or 500 ppm over the course of two generations (F 0 and F 1). Mean diazinon s for the F 0 generation during the premating period were 0, 0.77, 7.48 and mg/kg bw per day for males and 0, 0.77, 7.48 and mg/kg bw per day for females, respectively. The NOAEL for reproductive effects was 100 ppm (equal to 7.48 mg/kg bw per day), based on prolonged gestation duration, decrease in the number of pregnancies, and reduced fertility and mating indices at 500 ppm (equal to mg/kg bw per day). The NOAEL for parental effects was 10 ppm (equal to 0.77 mg/kg bw per day), based on reduced parental body weight gain at 100 ppm (equal to 7.48 mg/kg bw per day). The NOAEL for offspring toxicity was 10 ppm (equal to 0.77 mg/kg bw per day), based on reduced viability of pups and pup weights at 100 ppm (equal to 7.48 mg/kg bw per day). In another two-generation study on reproductive toxicity, rats received diazinon in the at a concentration of 0, 0.1, 1.0 or 10 mg/kg (equivalent to 0, , and 0.67 mg/kg bw per day, assuming concentrations are in mg/kg feed or ppm) over the course of two generations (F 0 and F 1). A rationale for the dose selection was not provided. There were no treatment-related effects observed in F 0 or F 1 parental animals or pups. The NOAEL for reproductive, parental and offspring toxicity was 10 ppm (equivalent to 0.67 mg/kg bw per day), the highest dose tested. In a range of studies on estrogenic and androgenic activities, no estrogenic, androgenic or antiandrogenic activity was observed at concentrations relevant to human exposure via the.

23 Diazinon 11 Overall NOAELs from the multigeneration studies in rats were identified. The overall NOAEL for reproductive effects was 100 ppm (equal to 7.48 mg/kg bw per day), based on effects at 500 ppm (equal to mg/kg bw per day). The overall NOAEL for parental toxicity was 10 ppm (equal to 0.77 mg/kg bw per day), based on effects at 100 ppm (equal to 7.48 mg/kg bw per day). The overall NOAEL for offspring toxicity was 10 ppm (equal to 0.77 mg/kg bw per day), based on effects at 100 ppm (equal to 7.48 mg/kg bw per day). In a study of developmental toxicity evaluated by the 1993 JMPR, rats were administered diazinon via gavage at a dose of 0, 15, 50 or 100 mg/kg bw per day. A marked decrease in maternal feed consumption correlating with weight loss at the beginning of the treatment period and a slightly higher incidence of incomplete ossification at different sites in the fetuses were observed at 100 mg/kg bw per day. As limited information was available from the previous JMPR monograph, the Meeting was unable to identify a NOAEL for this study. In a study of developmental toxicity, rats were administered diazinon via gavage at a dose of 0, 10, 20 or 100 mg/kg bw per day. The NOAEL for maternal toxicity was 20 mg/kg bw per day, based on body weight loss on gestation days 6 10, reduced body weight/body weight gains throughout treatment and decreased feed consumption on gestation days 6 9 at 100 mg/kg bw per day. The NOAEL for embryo/fetal toxicity was 20 mg/kg bw per day, based on an increased incidence of rudimentary 14th ribs at 100 mg/kg bw per day. In a study of developmental toxicity, rabbits were dosed with diazinon via gavage at 0, 7, 25 or 100 mg/kg bw per day. The NOAEL for maternal toxicity was 25 mg/kg bw per day, based on mortality, tremors, convulsions, hypoactivity, anorexia and reduced body weight gain observed at 100 mg/kg bw per day. The NOAEL for embryo/fetal toxicity was 100 mg/kg bw per day, the highest dose tested. In another developmental toxicity study, diazinon was administered to pregnant rabbits by gavage at a dose level of 0, 2.5, 10 or 40 mg/kg bw per day. The NOAEL for maternal toxicity was 10 mg/kg bw per day, based on clinical signs, decreased body weight and reduced feed consumption. The NOAEL for embryo/fetal toxicity was 10 mg/kg bw per day, based on decreased fetal weight at 40 mg/kg bw per day. The overall NOAEL for maternal toxicity in developmental toxicity studies in rabbits was 25 mg/kg bw per day, based on effects at 40 mg/kg bw per day, and the overall NOAEL for embryo/fetal toxicity was 10 mg/kg bw per day, based on effects at 40 mg/kg bw per day. The Meeting concluded that diazinon is not teratogenic. In a limited acute neurotoxicity study in which acetylcholinesterase activity was not measured, rats were dosed with diazinon at 0, 100, 300 or 500 mg/kg bw by gavage. The NOAEL was 100 mg/kg bw, based on systemic toxicity and clinical signs of neurotoxicity observed at 300 or 500 mg/kg bw. In another acute toxicity study, rats were administered a single dose of diazinon by gavage at 0, 2.5, 150, 300 or 600 mg/kg bw. The NOAEL was 2.5 mg/kg bw, on the basis of depressed erythrocyte acetylcholinesterase activity and behavioural changes at 150 mg/kg bw. In a third study, rats were administered a single dose of diazinon by gavage at 100, 250 or 500 mg/kg bw for males or 0, 0.05, 0.12, 0.25, 2.5, 25 or 250 mg/kg bw for females. The NOAEL was 2.5 mg/kg bw, on the basis of inhibition of brain and erythrocyte acetylcholinesterase activities in females at 25 mg/kg bw. In a study that investigated the time course of acute inhibition of acetylcholinesterase activity, rats were given a single dose of diazinon by gavage at 0, 2.5, 150, 300 or 600 mg/kg bw, and brain and blood samples were collected at 3, 9 and 24 hours after dosing. The NOAEL was 2.5 mg/kg bw, based on inhibition of brain and erythrocyte acetylcholinesterase activities at 150 mg/kg bw. Inhibition was observed beginning at 3 hours post-dosing, with maximal inhibition at 9 hours postdosing.

24 12 Diazinon The overall NOAEL in all studies of acute toxicity was 2.5 mg/kg bw, on the basis of inhibition of acetylcholinesterase activity in erythrocytes and in the brain at 25 mg/kg bw in rats of both sexes. Three studies were performed on delayed neurotoxicity in the hen. Oral doses of diazinon technical ranging from 10 to 100 mg/kg bw were administered to hens. Inhibition of cholinesterase activity was observed from 20 mg/kg bw, but there was no evidence that diazinon caused acute delayed neurotoxicity in the hen. No specific studies on immunotoxicity were submitted. A study in the open literature with intraperitoneal injection of diazinon in mice was not informative. The submitted repeated-dose toxicity studies do not indicate an immunotoxic potential for diazinon after oral exposure. Toxicological data on metabolites and/or degradates No toxicological data were available on any metabolites of diazinon other than diazoxon, which is the active metabolite of diazinon. However, the Meeting concluded that none of the other metabolites would be of toxicological concern at the levels present in the. Human data In a study of acute toxicity in male volunteers given ascending doses of diazinon (seven volunteers per group given 0.03, 0.12, 0.20 or 0.21 mg/kg bw; one volunteer given 0.30 mg/kg bw), acetylcholinesterase activity was not inhibited in erythrocytes at 0.21 mg/kg bw, the second highest dose tested. The highest dose (0.30 mg/kg bw) was not informative, as it was tested in a single volunteer only. Plasma cholinesterase activity was inhibited by more than 20% at doses above 0.12 mg/kg bw. Repeated-dose studies in four male volunteers given diazinon for days showed that, although there was some inhibition of plasma cholinesterase activity at the highest tested dose of 0.03 mg/kg bw per day (actual administered doses varied slightly, i.e. 0.03, 0.027, 0.022/0.027 and mg/kg bw per day), no inhibition of erythrocyte acetylcholinesterase activity was observed. Diazinon was evaluated in four male volunteers who received diazinon in capsules at mg/kg bw per day for days. There were no consistent treatment-related effects on erythrocyte acetylcholinesterase activity, blood chemistry or urine analysis. No clinical effects were reported. The NOAEL was mg/kg bw per day, the only dose tested. The overall NOAEL from repeated-dose studies in humans was 0.03 mg/kg bw per day. Several epidemiological studies on cancer outcomes following occupational exposure to diazinon were available. The review of these studies focused on the occurrence of three cancer types: NHL, leukaemia and lung cancer (see section 2.2). One prospective cohort study was available, the Agricultural Health Study (AHS), with a large sample size and detailed exposure assessment. Cohort studies are considered a powerful design, as recall bias is avoided. All other studies were case control studies, usually retrospective, which are more prone to recall and selection biases. There was no significant evidence of a positive association of NHL with diazinon exposure and no evidence of an exposure response relationship in the AHS. In a large pooled case control study, the unadjusted estimates showed a significant elevated risk of NHL (relative risk [RR] = 1.7; 95% confidence interval [CI] = ) associated with ever versus never use of diazinon. However, these risks were attenuated and/or no longer significant when proxy respondents were excluded and analyses were mutually adjusted for other pesticides (malathion, fonofos). Although increasing risk across exposure duration categories was observed, which was suggestive of a duration response pattern, confidence intervals were non-significant, wide and overlapping between categories. Two other studies reported elevated risks of NHL for ever versus never use of diazinon or high versus low

25 Diazinon 13 diazinon use, but confidence intervals were wide, reflecting uncertainty in the risk estimates, and chance could not be excluded as an explanation for the findings. Overall, there was no convincing evidence of a positive association between NHL and exposure to diazinon. A significantly increased risk of leukaemia in the highest exposure category (> 38.8 lifetime days of diazinon exposure; RR = 3.36; 95% CI = ) and a significant exposure response relationship were observed in the AHS. Findings for intensity-weighted lifetime exposure days demonstrated a similar pattern, but did not reach significance. Two other studies reported nonsignificantly elevated risks of leukaemia for high versus low diazinon use and ever versus never use of diazinon, with a non-significant dose response relationship observed using days of use per year. Overall, there is weak evidence of a positive association between leukaemia and exposure to diazinon from the AHS only. It is noted that the number of diazinon-exposed cases was low or not reported in all three available studies. A significant 60% excess risk of lung cancer in the highest exposure category (> 38.8 lifetime days of diazinon exposure) and a significant trend across exposure categories were observed in the AHS. Findings for intensity-weighted lifetime exposure days demonstrated a similar pattern, but did not reach significance. A separate analysis of ever use of diazinon versus never use from the AHS found no evidence of elevated risk of lung cancer among spouses of farmers/pesticide applicators; however, there were only 15 exposed cases. One other study reported a non-significant elevated risk of lung cancer for ever versus never use of diazinon (based on 17 exposed cases). Overall, there is weak evidence of a positive association between lung cancer and exposure to diazinon from the AHS cohort study only. In view of the lack of genotoxicity and the absence of carcinogenicity in mice and rats and considering the available epidemiological data from occupational exposure, the Meeting concluded that diazinon is unlikely to pose a carcinogenic risk to humans via exposure from the. The Meeting concluded that the existing database on diazinon was adequate to characterize the potential hazards to the general population, including fetuses, infants and children. Toxicological evaluation The Meeting identified inhibition of acetylcholinesterase activity as the most sensitive end-point after single or repeated doses of diazinon in all species. After considering all previously evaluated data and the new studies, the Meeting established an ADI of mg/kg bw, based on the overall NOAEL of 0.3 mg/kg bw per day from all repeated-dose toxicity studies, and using a safety factor of 100. This ADI was supported by the NOAEL of 0.03 mg/kg bw per day, the highest dose tested, identified in repeated-dose studies that involved a limited number of male volunteers, with application of a safety factor of 10. In 2006, the Meeting established an ADI of mg/kg bw, based on the highest NOAEL of 0.5 mg/kg bw per day for inhibition of erythrocyte acetylcholinesterase activity at 1 mg/kg bw per day in a 92-day repeated-dose toxicity study in rats and using a safety factor of 100. In this study, the ary concentrations of diazinon were converted to units of milligrams per kilogram body weight per day using a default conversion factor; the present Meeting considers this less reliable than the conversion using feed consumption data. The Meeting reaffirmed the ARfD of 0.03 mg/kg bw established by the 2006 JMPR. This ARfD was based on the NOAEL of 2.5 mg/kg bw identified in studies of acute (neuro)toxicity in rats, and using a safety factor of 100. This ARfD was supported by the NOAEL of 0.21 mg/kg bw, the highest dose tested, identified in the study in which a limited number of male volunteers were given a single dose of diazinon, with application of a safety factor of 10.