KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, KUMASI - GHANA COLLEGE OF HEALTH SCIENCE SCHOOL OF PUBLIC HEALTH ASSOCIATION BETWEEN EXPOSURE TO ORGANOCHLORINE AND PYRETHROID PESTICIDES AND NEUROBEHAVIORAL OUTCOMES AMONG CHILDREN UNDER FIVE YEARS OLD IN OFFINSO NORTH DISTRICT OF ASHANTI REGION, GHANA. BY FELIX BONNEY OCTOBER, 2019 i KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, KUMASI - GHANA ASSOCIATION BETWEEN EXPOSURE TO ORGANOCHLORINE AND PYRETHROID PESTICIDES AND NEUROBEHAVIORAL OUTCOMES AMONG CHILDREN UNDER FIVE YEARS OLD IN OFFINSO NORTH DISTRICT OF ASHANTI REGION, GHANA. A THESIS SUBMITTED TO THE SCHOOL OF PUBLIC HEALTH, COLLEGE OF HEALTH SCIENCES, KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, KUMASI, IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF MASTER OF SCIENCE DEGREE IN ENVIRONMENT AND PUBLIC HEALTH BY FELIX BONNEY (BSc Chemistry) OCTOBER, 2019 ii DECLARATION I, Felix Bonney hereby declare that, except for references to other people’s work which have been duly acknowledged, this write-up, submitted to the department of public health, school of research and graduate studies, KNUST, Kumasi, is the result of my own original research work and that this thesis has not been submitted to any institution by any student elsewhere for the award of any degree. ................................................ .................................... FELIX BONNEY DATE (PG 5468215) CERTIFIED BY ............................................... ........................................ DR. REGINALD QUANSAH DATE (ACADEMIC SUPERVISOR) CERTIFIED BY ……………………………... …………………………. DR. E. APPIAH – BREMPONG DATE (HEAD OF DEPARTMENT) iii ACKNOWLEDGEMENTS I wish to express my sincere gratitude to the Almighty God for his abundant grace, travelling mercies and divine protection and directions throughout this study. My profound gratitude also goes to Dr. Reginald Quansah, my supervisor for his valuable contributions, suggestion and corrections made to this work which, in no doubt, helped greatly in shaping this work. Special thanks go to Razak and his colleague Agriculture Extension Officers of Offinso-North district assembly for their assistance as data collection officers and their immense contribution during the organization of the farmer groups for the purpose of this work. I also wish to express my sincere gratitude to the director and staff of the Chemistry department, Ghana Atomic Energy Commission (GAEC), especially Beatrice, Elis and Gladys for their assistance during the laboratory analyses. It was great working with working with them. Finally, I will like to appreciate my wife, Millicent Fafa Amegbe and daughters (Biako, Keli and Norvinyo) for their endurance and support throughout this work. iv TABLE OF CONTENT DECLARATION iii ACKNOWLEDGEMENT iv TABLE OF CONTENT v LIST OF TABLES ix LIST OF FIGURES x LIST OF ABBREVIATIONS xi ABSTRACT xiii CHAPTER ONE 1 INTRODUCTION 1 1.1 Background of study 1 1.2 Problem Statement 3 1.3 Conceptual Framework 4 1.4 Justification 7 1.5 Objectives of study 8 1.5.1 Main Objectives 8 1.5.2 Specific Objectives 8 CHAPTER TWO 9 2.0 LITERATURE REVIEW 9 2.1 Scope of the Review 9 2.2 Definition of Pesticides 9 2.3 History and Uses of Pesticides 10 2.4 Classification of pesticides 13 2.4.1 Organochlorine Pesticides (OCPs) 13 2.4.2 Pyrethroids 14 2.4.3 Organophosphate pesticides (OPs) 15 2.4.4 Carbamates 15 v 2.5 Effects of pesticides on the environment and on human health 16 2.6 Pesticides and behavioral problems in children 18 2.6.1 Organochlorines and behavioral problems in children 19 2.6.2 Organophosphates and ADHD in children 20 2.6.3 Pyrethroids and ADHD in children 22 2.7 Routes of exposure of pesticides 22 2.8 Metabolism of pesticides 23 2.9 Biomarkers of exposure of pesticides 24 2.10 Registration and regulatory requirements regarding pesticide use in Ghana 26 2.11 Conclusion 27 CHAPTER THREE 29 3.0 MATERIAL AND METHODOLOGY 29 3.1 Study Design 29 3.2 Study Location 29 3.3 Source/study population 31 3.3.1 Inclusion Criteria 31 3.3.2 Exclusion Criteria 31 3.4 Study Variables 32 3.4.1 Independent variables of Interest 32 3.4.2 Dependent Variables 32 3.4.3 Confounding variables 32 3.5 Sample size calculation and Sampling procedure 33 3.5.1 Sample size calculation 33 3.5.2 Sampling procedure 34 3.6 Pretest of data collection tools 34 3.7 Data collection procedure 34 3.8 Quality control 35 vi 3.9 Data Processing and Analyses 36 3.10 Privacy and Security of Records 36 3.10.1 Protection of subjects' privacy 36 3.10.2 Provision to prematurely end participation in the study 37 3.10.3 Record storage and protection 37 3.10.4 Destruction of data and specimens at the conclusion of study 37 3.11 Ethical consideration 37 3.12 Study limitation 38 CHAPTER FOUR 39 4.0 RESULTS 39 4.1 Socio-Demographic characteristics 39 4.2 Determinants of interest 40 4.2.1 Objective 1: Means of pesticide exposure at home, in the farm or both and their prevalence 40 4.2.2 Objective 2: Urinary residual levels of Organochlorine and pyrethroid pesticides 42 4.3 Objective 3: Mean behavioral scores of children 45 4.4 Objective 4: Association between exposure indicators and behavioral outcomes 45 4.4.1. Exposure indicators and Attention 45 4.4.2. Exposure indicators and Rule-Breaking 49 4.4.3. Exposure indicators and Social behavior 52 4.4.4. Exposure indicators and Aggressiveness 55 4.5 Objective 4: Association between urinary concentration and behavioral outcomes 58 CHAPTER FIVE 65 5.0 DISCUSSION 65 5.1 Main Findings 65 5.2 Validity of Method 66 5.3 Comparing this study with previous literature 67 vii CHAPTER SIX 69 6.0 CONCLUSIONS AND RECOMMENDATIONS 69 6.1 Conclusion 69 6.2. Recommendations 69 REFFERENCES 71 APPENDIXES 91 APPENDIX A: INFORMATION LEAFLET AND CONSENT FORM 91 APPENDIX B: QUESTIONNAIRE 94 APPENDIX C: CHILD BEHAVIOR CHECKLIST 96 APPENDIX D: VARIABLES FOR ANALYSIS 100 viii LIST OF TABLES Table 4.1: Characteristics of study population of children under five (5) years of age 39 Table 4.2.1: Prevalence of exposure indicators 41 Table 4.2.2a: Mean pesticide residue concentration for all ages; 0 to 4 years 42 Table 4.2.2b: Mean pesticide residue concentration for 0 to 2 years old children 43 Table 4.2.2c: Mean pesticide residue concentration in 3 to 4 years old children 44 Table 4.3: Mean behavioral outcomes of children of vegetable farmers 45 Table 4.4.1: Association between exposure indicators and attention 47 Table 4.4.2: Association between exposure indicators and rule-breaking 50 Table 4.4.3: Association between exposure indicators and social behavior 53 Table 4.4.4: Association between exposure indicators and aggressiveness 56 Table 4.5: Association between urinary residue concentration and behavioral outcomes 61 ix LIST OF FIGURES Figure 1.1: Conceptual frame work 6 Figure 3.1: A map of the study location 30 x LIST OF ABBREVIATIONS AChE - Acetylcholinesterase ASEBA - Achenbach System of Empirically Based Assessment ADHD - Attention deficit/hyperactivity disorder CBCL - Child Behavior Checklist ChE - Cholinesterase DAP - Dialkyl phosphate DDE - Dichlorodiphenyldichloroethylene DDT - Dichlorodiphenyltricholoroethane DEDTP - Diethyldithiophosphate DEP - Diethylphosphate DETP - Diethylthiophosphate DMAP - Dimethyl alkylphosphate DMDTP - Dimethyldithiophosphate DMP - Dimethylphosphate DMTP - Dimethylthiophosphate EPA - Environmental Protection Agency FAO - Food and Agriculture Organisation GAEC - Ghana Atomic Energy Commission GDP - Gross Domestic Product HCH - Hexachlorocyclohexane IQ - Intelligence quotient IPM - Integrated Pest Management WHO - World Health Organisation OC - Organochlorines OCPs - Organochlorine Pesticides ONFAS - Offinso North District Farm Health Study OP - Organophosphates PCBs - Polychlorinated biphenyl PCDD/Fs - Polychlorinated dibenzodioxins/furans PDD - Pervasive Developmental Disorder xi PON - Paraoxonase POPs - Persistent Organic Pollutants SD - Standard deviation α-HCH - Alpha Hexachlorocyclohexane β-HCH - Beta Hexachlorocyclohexane γ-HCH - Gamma Hexachlorocyclohexane δ-HCH - Delta Hexachlorocyclohexane xii ABSTRACT Pesticide use for agricultural purposes in Ghana has increased over the years with its related health threats to farmers, people living around farming communities as well as the environment due to unsafe handling practices and application. This cross-sectional study conducted at three farming communities in Offinso North District of Ashanti Region, Ghana was aimed at assessing the association between exposure to organochlorine and pyrethroid pesticides and neurobehavioral outcomes defined as attention, rule-breaking, social behavior and aggressiveness. The target population was children under five years old. Questionnaire data on exposure practices and child behaviors as well as urine samples were taken for analyses, from 170 children whose parents were vegetable farmers. Majority of the children, 61.18% had contact with pesticide contaminated surfaces at home, 69.41% places thumbs/ fingers in the mouth and 84.29% places contaminated objects in the mouth. In the farm, 55.29% of the children had contact with pesticide contaminated surfaces, 61.76% places thumbs/ fingers in the mouth and 54.12% places contaminated objects in their mouths. There were also significant levels of pesticide residues of five organochlorines and one pyrethroid in their urines. The mean residual concentration of gamma-HCH found was 3.09μg/l (SD = 0.77μg/l); beta-HCH = 2.89μg/l (SD = 0.64μg/l); delta-HCH = 2.42μg/l (SD = 0.43μg/l); heptachlor = 3.55μg/l (SD = 0.90μg/l); lambda cyhalothrin = 3.11μg/l (SD = 0.69μg/l). There was no significant association found between urinary pesticide residues and neurobehavioral outcomes. However, there were significant inverse associations between exposure indicators at home, in the farm or both and Attention, Rule-Breaking, Social behavior and Aggressiveness with the association being strongest among children aged between 3 to 4 years. xiii CHAPTER ONE INTRODUCTION 1.1 Background of Study The agricultural sector accounts for a comparatively small portion of the world’s economy, but remains central to the survival of many people. In 2015, an estimated 1.6 billion people out of the world’s population of 7.3 billion were directly engaged in agriculture.