CERTIFICATION
We certify that the thesis titled “Organochlorine Pesticide Residues in Shellfishes and Finfishes from Lagos Lagoon” is an original work carried out by Mr. Akan Bassey Williams (CUGP040105) in the Department of Chemistry, Covenant University, Ota, Ogun State under the supervision of Dr. Olusegun Ayejuyo and Prof. M. Adediran Mesubi.We have examined and found the work acceptable for the award of a degree of Doctor of Philosophy in Environmental Chemistry.
Dr. Olusegun Ayejuyo Signature / Date …………………..
(Supervisor)
Department of Chemistry,
University of Lagos.
Prof. M. Adediran Mesubi Signature / Date …………………..
(Co-Supervisor)
Head, Department of Chemistry,
Covenant University.
Prof. Percy Onianwa Signature / Date……………………
(External Examiner)
Department of Chemistry,
University of Ibadan.
Prof. Fredrick Hymore Signature / Date……………………
Dean, College of Science & Technology
Covenant University.
DEDICATION
This thesis is dedicated to the Almighty God, my creator and provider. To Him alone be all the praise and adoration.
ACKNOWLEDGEMENT
I return the glory to God for enabling me to complete this research. I am indebted to my Supervisor, Dr. Olusegun Ayejuyo and to my co-Supervisor, Prof. M. Adediran Mesubi, for their guidance. The Chancellor of Covenant University, Dr. David Oyedepo, the Board of Regents, the Vice-Chancellor, Prof. Aize Obayan, the Deputy Vice-Chancellor, Prof. Charles Ogbulogo, the pioneer Registrar, Pastor Yemi Nathaniel, and the former Registrar, Dr. Daniel Rotimi, deserve my deep appreciation. Apart from providing the research platform, the gas chromatograph used for the analyses was purchased by the University at great cost to facilitate my work. The Dean, School of Post Graduate Studies, Prof. Chris Awonuga is appreciated. The Dean, College of Science and Technology, Prof. Fredrick Hymore; the immediate past Dean, Prof. James Katende; the Deputy Dean, School of Natural and Applied Sciences, Prof. Louis Egwari, and my immediate past Head of Department, Prof. JohnBull Echeme, have been very supportive.
My external examiner, Prof. Percy Onianwa is deeply appreciated for his scholarly contribution. The mentoring roles of Prof. Oladele Osibanjo, Prof. Olukayode Bamgbose and Prof. Toyin Arowolo are acknowledged. I appreciate my assessors, Prof. Olubode Ajayi, Prof. Kehinde Okonjo and Dr. Aderemi Ogunfowokanfor their constructive assessment.Also, the input of Prof. Samuel Adefila, Prof. BabatundeElemo, Prof. Josiah Bello, Prof. Adeleke Adeniyi, Prof. Emil Asuquo, Prof. Kenneth Adekalu, Dr. Ife Adewumi, Dr. George Ofunne, Dr. Joe Essien, Dr. Mfon Udoh, Dr. Nsikak Benson, Mr. John Paul Unyimadu, Messrs Attah, Emmanuel, Elegbede, Hanson, Ogamba and assistance of Dr.OlayiwolaAfolayan, Dr. Obasola Fagade, Dr. Victor Fodeke, Olukayode Philips, AyorindeFalomo, AbbeyAjireloja and Olatunde Ogunleye have been helpful. I treasure the friendship and encouragement from Dr. Idara Akpabio, Dr. Ekanem Etuk, Dr. Akan Udom, Dr. Ken Opara and Dr. Goddy Akpan. I am indebted to the Environmental Chemistry Research Group (ENCREG) and the entire Faculty and Staff of the Department of Chemistry for their support. My colleagues in the University are also acknowledged. I appreciate the prayers from the Pastorate and membership of Living Faith Church. I deeply appreciate my lovely wife, Mrs Lifted Williams for her love, prayers and assistance in identifying and dissecting the fish organs. I also appreciate my mother, Mrs Akon Williams for her prayers. My siblings and relations are hereby acknowledged.
Williams Akan Bassey
TABLE OF CONTENTS
TITLE PAGE ...... ………………………………………………………………...... i
CERTIFICATION ...…………………………………………………………………...... ii
DEDICATION………………………………………………………………………….....iii
ACKNOWLEDGEMENT……………………………………………………………...... iv
TABLE OF CONTENTS …………………………………………………………...... v
LIST OF TABLES ...…………………………………………………………………...... x
LIST OF FIGURES ...... …………………………………………………………...... xvi
LIST OF PLATES …………………………………………………………………….....xvii
LIST OF ACRONYMS AND ABBREVIATIONS……………………………………..xix
ABSTRACT ...... ………………………………………………………………...... xxiii
CHAPTER ONE
1.0 Introduction…………………………………………………………………….....1
1.1 Introduction to Pesticides...... 1
1.2 Introduction to Fishery Resources in Lagos Lagoon...... 3
1.3 Background of the Study ………………………………………………………....4
1.4 Statement of the Problem………………………………………………………....7
1.5 Justification forthe Study………………………………………………………...7
1.6 Aim of the Study...... ………………………………………………………....9
1.7 Objectives of the Study……………………………………………………...... 10
1.8 Limitations of the Study...... 10
CHAPTER TWO
2.0 Literature Review……………………………………………………………...... 11
2.1 Review of Previous Studies on OCPs in Water, Sediment and Fishes...... 11
2.2 Lagoon Ecosystem ……………………………………………………………....15
2.2.1 Types of Lagoon…………………………………………………………...... 17
2.2.1.1 Coastal Lagoons…………………………………………………………...... 17
2.2.1.2 Estuaries…………………………………………………………………...... 18
2.3 Finfishes……… ……………………………………………………………....19
2.3.1 Classification of Fishes ……………………………………………….…...... 19
2.3.2 Tilapia……………………………………………………………………...... 20
2.3.3 Mullet (Liza grandisquamis)………………………………………………...... 22
2.3.4 Cat Fish (Chrysichthys nigrodigitatus)……………………………………...... 22
2.3.5 Bonga Fish (Ethmalosa fimbriata)……………………………………...... 23
2.3.6 African Moony (Psettias sebae)…………………………………………….....23
2.4 Shellfishes...... 23
2.4.1 Crabs...... 24
2.4.2 Shrimps...... 24
2.4.3 Prawns...... 25
2.4.4 Crayfishes...... 25
2.5 Persistent Organic Pollutants……………………………………………….....26
2.5.1 Classification of Persistent Organic Pollutants…………………………...... 26
2.5.1.1 Polycyclic Aromatic Hydrocarbons (PAHs)……………………………...... 26
2.5.1.2 Halogenated Hydrocarbons………………………………………………...... 27
2.5.1.2.1 Organochlorine Pesticides (OCPs)………………………………………...... 27
2.5.1.2.1.1 Dichlorodiphenyltrichloroethane (DDT)………………………………...... 29
2.5.1.2.1.2 Benzene Hexachloride (BHC)…………………………………………...... 31
2.5.1.2.1.3 Hexachloro Benzene (HCB)……………………………………………….....32
2.5.1.2.1.4 Chlordane………………………………………………………………...... 33
2.5.1.2.1.5 Aldrin……………………………………………………………………...... 33
2.5.1.2.1.6 Dieldrin...... 34
2.5.1.2.1.7 Endrin…………………………………………………………………...... 34
2.5.1.2.1.8 Heptachlor………………………………………………………………….....35
2.5.1.2.1.9 Endosulfan………………………………………………………………...... 36
2.5.1.2.1.10 Methoxychlor…………………………………………………………...... 37
2.5.1.2.1.11 Mirex…………………………………………………………………...... 38
2.5.1.2.1.12 Dioxins……………………………………………………………………...... 38
2.5.1.2.1.13 Furans…………………………………………………………………...... 39
2.5.1.2.1.14 Toxaphene……………………………………………………………...... 40
2.5.1.2.2 Polychlorinated Biphenyls (PCBs)……………………………………...... 41
Top of Form
Top of Form
Top of Form
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Bottom of Form
Bottom of Form
2.5.2 Environmental Behaviour and Fate of Persistent Organic Pollutants……....43
2.5.2.1 Fate Processes of Pesticides…………………………………………...... 44
2.5.3 Chemistry and Toxicology of Persistent Organic Pollutants……...... 49
2.5.3.1 Chemistry of Persistent Organic Pollutants…………………………...... 49
2.5.3.2 Toxicology of Persistent Organic Pollutants……………………...... 50
2.6 Analytical Methods of OCP Determination...... 51
2.6.1 Gas Chromatograph coupled with Electron Capture Detector (GC-ECD)....52
2.6.2 Gas Chromatograph coupled with Mass Spectrometer (GC-MS)...... 52
2.6.3 Enzyme-linked Immunoabsorbent Assays (ELISAs)...... 53
2.7 Chromatography………………………………………………...... 54
2.7.1 Chromatographic Mechanisms…………………………………...... 54
2.7.2 Forms of Chromatography……………………………………….……...... 55
2.7.2.1 Gas Chromatography…………………………………………………...... 56
2.7.2.1.1 Gas Chromatographic Components………………………...... 57
2.7.2.1.1.1 Carrier Gas………………………………………………….….…...... 58
2.7.2.1.1.2 Sample-injection System……………………………………………...... 58
2.7.2.1.1.3 Gas-chromatographic Columns………………………………………...... 59
2.7.2.1.1.4 Stationary Phase……………………………………………………...... 61
2.7.2.1.1.5 Liquid Phase………………………………………………………...... 62
2.7.2.1.1.6 Temperature Control……………………………………………...... 62
2.7.2.1.1.7 Detectors…………………………………………………………...... 64
2.7.2.1.1.7.1 Electron Capture Detector (ECD)…………………………………….…...... 65
2.7.2.1.1.7.2 Flame-ionization Detector (FID)………………………………………...... 66
2.7.2.1.1.7.3 Thermal Conductivity Detector (TCD)………………………………...... 67
2.7.2.1.1.7.4 Thermionic Ionization Detector (TID)…………………………………...... 67
2.7.2.1.1.7.5 Flame Photometric Detector (FPD)……………………………………...... 68
2.7.2.1.1.7.6 Photo Ionization Detector (PID)………………………………………...... 68
2.7.2.1.1.7.7 Electrolytic Conductivity Detector (EICD)…………………………...... 69
2.7.2.1.1.7.8 Chemiluminescence–redox Detector………………………………….....70
2.7.2.1.1.8 Use of Chromatograms for Gas Chromatographic Analyses………….....70
2.7.2.1.1.8.1 Qualitative Analysis…………………………………………….…...... 71
2.7.2.1.1.8.2 Quantitative Analysis……………………………………………...... 71
2.7.2.1.1.8.2.1 Geometric Methods…………………………………………………...... 71
2.7.2.1.1.8.2.2 Automatic Integration………………………………………………...... 72
2.7.2.1.1.8.2.3 Evaluation Methods……………………………………………...... 72
2.7.2.1.1.8.2.3.1 Calibration by Standards……………………………………………...... 72
2.7.2.1.1.8.2.3.2 Area Normalization…………………………………………...... 72
2.7.2.1.1.8.2.3.3 Internal Standard……………………………………………………...... 73
2.7.2.1.1.8.2.3.4 Standard Addition…………………………………….………...... 73
2.7.3 Applications of Chromatography…………………………….………...... 74
CHAPTER THREE
3.0 Materials and Methods…………………………………………………………...... 75
3.1 Study Area……………………………………………………………………...... 75
3.2 Sampling Strategy……………………………………………………………...... 75
3.2.1 Pre-treatment of Sampling and Storage Vessels...... 77
3.2.2 Collection of Water Samples…………………………………………………...... 77
3.2.3 Collection of Sediment Samples……………………………………………...... 77
3.2.4 Collection of Fish Samples…………………………………………………...... 78
3.3 Determination of Physicochemical Properties of Water...... ……...... 80
3.3.1 Colour…………………………………………………………………………...... 80
3.3.2 Odour…………………………………………………………………………...... 80
3.3.3 Temperature…………………………………………………………………...... 80
3.3.4 pH……………………………………………………………………………...... 80
3.3.5 Conductivity…………………………………………………………………...... 80
3.3.6 Total Dissolved Solids (TDS)………………………………………….…...... 80
3.3.7 Salinity……………………………………………………………………...... 81
3.3.8 Turbidity……………………………………………………………………...... 81
3.4 Evaluation of Sediment Particle Sizes…………………………………………...... 81
3.5 Characterization of Fishes…………………………………………………...... 81
3.5.1 Determination of Sex…………………………………………………………...... 81
3.5.2 Measurement of Length……………………………………………………...... 82
3.5.3 Evaluation of Percentage Dry Matter……………………………………………...82
3.5.4 Calculation of Condition Factor………………………………………………...... 82
3.5.5 Determination of Fat Content………………………………………...... 82
3.6 Treatment of Samples for Determination of OCP...... 83
3.6.1 Extraction of Water Samples for Determination of OCP...... 83
3.6.2 Extraction of Sediment Samples for Determination of OCP...... 83
3.6.3 Extraction of Fish Samples for Determination of OCP...... 83
3.6.4 Pre-concentration of Extracts...... 84
3.6.5 Clean-up of Extracts...... 84
3.7 Identification and Determination of OCP Residues by Gas Chromatography...... 84
3.8 Quality Assurance...... 86
3.8.1 Recovery Study...... 86
3.8.2 Determination of Method Detection Limits (MDLs)...... 86
3.9 Determination of Limit of Detection (LOD)...... 87
3.10 Determination of Limit of Quantification (LOQ)...... 87
3.11 Determination of Bioconcentration Factor (BCF) andBiota-Sediment
Accumulation Factor (BSAF)...... 87
3.12 Estimation of Daily Intakes(EDI) of Organochlorine Pesticide Residues by
Humans...... 87
3.13 Analyses of Data...... 88
CHAPTER FOUR
4.0 Results and Discussion ...... ……………………………………………89
4.1 Conclusion…………………………………………………………………...... 151
4.2 Recommendations…………………………………………………………...... 152
REFERENCES………………………………………………………………………...... 153
APPENDICES………………………………………………………………………...... 168
LIST OF TABLES
Table 2.1: Classification of the Phylum Chordata…………….………………...... 20
Table 2.2: Structural Classification of Organochlorine Insecticides…………...... 29
Table 3.1: Sampled Finfishes for the Determination of OCP Residues...... 79
Table 3.2: Sampled Shellfishes for the Determination of OCP Residues...... 79
Table 3.3: Operating Conditions of the Gas Chromatograph...... 85
Table 4.1: Mean Values of Physicochemical Properties of Microlayer Water
during the Dry and Wet Seasons…………...... 89
Table 4.2: Mean Values of Physicochemical Properties of Mixed Layer Water
during the Dry and Wet Seasons...... 90
Table 4.3: Comparative Statistics of Physicochemical Properties of Microlayer
Water in Agboyi, Oworonshoki, Ajara, Ogogoro and Tarkwa Bay
during the Dry Season...... 91
Table 4.4: Correlations among Physicochemical Properties of Microlayer Water
in Agboyi Oworonshoki, Ajara, Ogogoro and Tarkwa Bay during the
DrySeason...... 91
Table 4.5: Comparative Statistics of Physicochemical Properties of Microlayer
Water in Agboyi, Oworonshoki, Ajara, Ogogoro and Tarkwa Bay
during the Wet Season...... 92
Table 4.6: Correlations among Physicochemical Properties of Microlayer Water
in Agboyi Oworonshoki, Ajara, Ogogoro and Tarkwa Bay during the
Wet Season...... 92
Table 4.7: Comparative Statistics of Physicochemical Properties of Mixed Layer
Water in Agboyi, Oworonshoki, Ajara, Ogogoro and Tarkwa Bay
during the Dry Season...... 93
Table 4.8: Correlations among Physicochemical Properties of Mixed Layer Water
in Agboyi Oworonshoki, Ajara, Ogogoro and Tarkwa Bay during the
Dry Season...... 93
Table 4.9: Comparative Statistics of Physicochemical Properties of Mixed Layer
Water inAgboyi, Oworonshoki, Ajara, Ogogoro and Tarkwa Bay
during the Wet Season...... 94
Table 4.10: Correlations among Physicochemical Properties of Mixed Layer
Water in Agboyi Oworonshoki, Ajara, Ogogoro and Tarkwa Bay
during the Wet Season...... 94
Table 4.11: Mean Values of Properties of Epipellic Sediment during the Dry
and Wet Seasons……...... 95
Table 4.12: Mean Values of Properties of Benthic Sediment during the Dry
and Wet Seasons………...... 95
Table 4.13: Mean Biometric Data of Finfishes in Agboyi Creekduring the Dry
Season...... 96
Table 4.14: Mean Biometric Data of Finfishes in Agboyi Creekduring the Wet
Season...... 96
Table 4.15: Mean Biometric Data of Finfishes in Lagos Lagoonduring the Dry
Season...... 97
Table 4.16: Mean Biometric Data of Finfishes in Lagos Lagoonduring the Wet
Season...... 98
Table 4.17: Mean Biometric Data of Shellfishes in Agboyi Creekduring the Dry
Season...... 99
Table 4.18: Mean Biometric Data of Shellfishes in Agboyi Creekduring the Wet
Season...... 99
Table 4.19: Mean Biometric Data of Shellfishes in Lagos Lagoonduring the Dry
Season...... 100
Table 4.20: Mean Biometric Data of Shellfishes in Lagos Lagoonduring the Wet
Season...... 100
Table 4.21: Recoveries, Method Detection Limits (MDLs) and the Relative
Standard Deviation (RSD), Limits of Detection (LOD) and Limits
of Quantification (LOQ) of OCPs in Water Samples...... 101
Table 4.22: Recoveries, Method Detection Limits (MDLs) and the Relative
Standard Deviation (RSD) of OCPs in Sediment Samples...... 102
Table 4.23: Recoveries, Method Detection Limits (MDLs) and the Relative
Standard Deviation (RSD) of OCPs in Fish Samples...... 103
Table 4.24: Mean Concentrations (ng/mL) of Organochlorine Pesticide Residues
inMicrolayer and Mixed Layer Water during the Dry Season...... 104
Table 4.25: Mean Concentrations (ng/mL) of Organochlorine Pesticide Residues
in Microlayer and Mixed Layer Water during the Wet Season...... 105
Table 4.26: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in Epipellic and Benthic Sediments during the Dry Season...... 106
Table 4.27: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in Epipellic and Benthic Sediments during the Wet Season...... 107
Table 4.28: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inthe Muscle Tissues of Male and Female Tilapia guineensis
during the Dry and Wet Seasons...... 108
Table 4.29: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Muscle Tissues of Male and Female Tilapia
(Sarothorodon melanotheron) during the Dry and Wet Seasons...... 109
Table 4.30: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Muscle Tissues of Male and Female Bonga Fish
(Ethmalosa fimbriata) during the Dry and Wet Seasons in Lagos Lagoon.....110
Table 4.31: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Muscle Tissues of Male and Female Catfish
(Chrysichthys nigrodigitatus) during the Dry and Wet Seasons...... 111
Table 4.32: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Muscle Tissues of Male and Female Mullet
(Lizagrandisquamis) during the Dry and Wet Seasons...... 112
Table 4.33: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Muscle Tissues of Male and Female African Moony
(Psettias sebae)during the Dry and Wet Seasons in Lagos Lagoon...... 113
Table 4.34: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Grouper
(Epinephelus aeneus) during the Dry and Wet Seasons in Lagos Lagoon.....114
Table 4.35: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Barracuda
(Sphyraena guachancho) during the Dry and Wet Seasons...... 115
Table 4.36: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Croaker
(Pseudotolithus senegalensis) during the Dry and Wet Seasons
in Lagos Lagoon...... 116
Table 4.37: Mean Concentrations (ng/g) of Organochlorine pesticide
Residues in the Muscle Tissues of Male and Female Croaker
(Pseudotolithus typus) during the Dry and Wet Seasons in
Lagos Lagoon...... 117
Table 4.38: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Tongue Sole
(Cynoglossus canariensis) during the Dry and Wet Seasons in
Lagos Lagoon...... 118
Table 4.39: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Snapper
(Lutjanus goreensis) during the Dry and Wet Seasons in
Lagos Lagoon...... 119
Table 4.40: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Herring
(Sardinella maderensis) during the Dry and Wet Seasons in
Lagos Lagoon...... 120
Table 4.41: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Jack Fish
(Caranx hippos) during the Dry and Wet Seasons...... 121
Table 4.42: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues in the Muscle Tissues of Male and Female Oarfish
(Regalecus glesne) during the Dry and Wet Seasons in Lagos Lagoon...... 122
Table 4.43: Mean Concentrations (ng/g) of Organochlorine Pesticide
Residues inthe Gills of Male and Female Tilapia guineensis
during the Dry and Wet Seasons...... 123
Table 4.44: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Tilapia (Sarothorodon melanotheron)
during the Dry and Wet Seasons in Agboyi Creek...... 124
Table 4.45: Mean concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Tilapia (Sarothorodon melanotheron)
during the Dry Season in Lagos Lagoon...... 125
Table 4.46: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Tilapia (Sarothorodon melanotheron)
during the Wet Season in Lagos Lagoon...... 126
Table 4.47: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Organs of Male and Female Bonga fish (Ethmalosa fimbriata)
during the Dry and Wet Seasons in Lagos Lagoon...... 127
Table 4.48: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Catfish (Chrysichthys nigrodigitatus)
during the Dry Season in Agboyi Creek...... 128
Table 4.49: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of male and female Catfish (Chrysichthys nigrodigitatus)
during the wet season in Agboyi Creek...... 129
Table 4.50: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Catfish (Chrysichthys nigrodigitatus)
during the Dry Season in Lagos Lagoon...... 130
Table 4.51: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Catfish (Chrysichthys nigrodigitatus)
during the Wet Season in Lagos Lagoon...... 131
Table 4.52: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in Gills of Male and Female Mullet (Lizagrandisquamis) during
the Dry and Wet Seasons in Agboyi Creek...... 132
Table 4.53: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Mullet (Lizagrandisquamis) during
the Dry Season in Lagos Lagoon...... 133
Table 4.54: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inOrgans of Male and Female Mullet (Lizagrandisquamis) during
the Wet Season in Lagos Lagoon...... 134
Table 4.55: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
in the Gills of Male and Female African Moony (Psettias sebae)
duringthe Dry and Wet Seasons in Lagos Lagoon...... 135
Table 4.56: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inMuscle Tissues of Male and Female Crab (Ocypoda africanus)
during the Dry and Wet seasons...... 136
Table 4.57: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inMuscle Tissues of Male and Female Shrimp (Penaeus notialis)
during the Dry and Wet Seasons...... 137
Table 4.58: Mean Concentrations (ng/g) of Organochlorine Pesticide Residues
inMuscle Tissues of Male and Female Crayfish (Procambarus clarkii)
during the Dry and Wet Seasons...... 138
Table 4.59: Bioconcentration Factor at Agboyi Creek………………………………….139
Table 4.60: Bioconcentration Factor at Lagos Lagoon………………………………….139
Table 4.61: Biota-Sediment Accumulation Factor at Agboyi Creek……………………140
Table 4.62: Biota-Sediment Accumulation Factor at Lagos Lagoon……………………140
Table 4.63: Estimated Daily Intakes (EDI) of OCP Residues
(ng/kg Body Weight/Day) by Humans……………………………………...141
Table 4.64: Acceptable Daily Intake(µg/kg Body Weight/Day) of
OrganochlorinePesticide Residues in Fish...... 142
LIST OF FIGURES
Figure 2.1: Schematic Diagram of a Typical Gas Chromatograph……………...... 57
Figure 3.1: Map of Lagos Lagoon and Surrounding Areas Showing
the Sampling Points...... 76
LIST OF PLATES
Plate 1: Agboyi Creek Terminus…………………………………………………...... 172
Plate 2: Investigator Williams Identifying Sampling Locations with
Garmin-GPSMAP 76S...... 172
Plate 3: Shellfishes Sampled for Organochlorine Pesticide Analysis…………………....173
Plate 4: Crab (Ocypoda africanus) Sampled for Organochlorine Pesticide
Analysis...... 173
Plate 5: Shrimp (Penaeus notialis) Sampled for Organochlorine Pesticide
Analysis...... 174
Plate 6: Crayfish (Procambarus clarkii) Sampled for Organochlorine Pesticide
Analysis...... 174
Plate 7: Tilapia (Tilapia guineensis) Sampled for Organochlorine Pesticide
Analysis...... 175
Plate 8: Mullet (Lizagrandisquamis) Sampled for Organochlorine Pesticide
Analysis...... 175
Plate 9: Catfish (Chrysichthys nigrodigitatus) Sampled for Organochlorine
Pesticide Analysis...... 176
Plate 10: African Moony (Psettias sebae) Sampled for Organochlorine Pesticide
Analysis...... 176
Plate 11: Bonga Fish (Ethmalosa fimbriata) Sampled for Organochlorine
Pesticide Analysis...... 177
Plate 12: Grouper (Epinephelus aeneus) Sampled for Organochlorine Pesticide
Analysis...... 177
Plate 13: Barracuda (Sphyraena guachancho) Sampled for Organochlorine
Pesticide Analysis...... 178
Plate 14: Croaker (Pseudotolithus senegalensis) Sampled for Organochlorine
Pesticide Analysis...... 178
Plate 15: Croaker (Pseudotolithus typus) Sampled for Organochlorine Pesticide
Analysis...... 179
Plate 16: Tongue Sole (Cynoglossus canariensis) Sampled for Organochlorine
Pesticide Analysis...... 179
Plate 17: Snapper (Lutjanus goreensis) Sampled for Organochlorine
Pesticide Analysis...... 180
Plate 18: Herring (Sardinella maderensis) Sampled for Organochlorine
PesticideAnalysis...... 180
Plate 19: Jack Fish (Caranx hippos) Sampled for Organochlorine Pesticide
Analysis...... 181
Plate 20: Oarfish(Regalecus glesne) Sampled for Organochlorine Pesticide
Analysis...... 181
LIST OF ACRONYMS AND ABBREVIATIONS
ADI Acceptable Daily Intake
AGR Agboyi Creek
ATSDR Agency for Toxic Substances and Disease Registry
BCF Bioconcentration Factor
BHC Benzene Hexachloride
BSAF Biota-Sediment Accumulation Factor
CF Condition Factor
CL Carapace Length
DDD Dichlorodiphenyldichloroethane
DDE Dichlorodiphenylethane
DDT Dichlorodiphenyltrichloroethane
EDI Estimated Daily Intake
EICD Electrolytic Conductivity Detector
EPA Environmental Protection Agency
FAO Food and Agriculture Organisation
FDC Fish Daily Consumption
FEPA Federal Environmental Protection Agency