ABSTRACT
The analysis for the heavy metal concentration in different parts of Chrysichthys nigrodigitatus was carried out using Atomic Absorption Spectrophotometer. The result of the analysis reveals that the samples (gills, stomach and liver) accumulated all the analysed metals. The results of the analysis were as follows; Gills: Chromium 0.036±0.029, Nickel 0.011±0.0017, Lead 0.138±0.0055, Zinc 1.344±0.0012, Cadmium 0.022±0.0017, Liver: Chromium 0.028±0.023, Nickel 0.077±0.0012, Lead 0.06±0.0017, Zinc 0.765±0.00056, Cadmium 0.083±0.0012 and Stomach: Chromium 0.043±0.0017, Nickel 0.024±0.012, Lead 0.343±0.00058, Zinc 0.911±0.0023, Cadmium 0.055±0.0017. This results were within the WHO stipulated standard. Hence, C. nigrodigitatus should be prepared properly before consumption.
TABLE OF CONTENTS
CONTENTS PAGE
Title Page – – – – – – – – i
Certification – – – – – – – ii
Dedication – – – – – – – – iii
Acknowledgements – – – – – – iv
Abstract – – – – – – – vii
Table of Contents – – – – – – – viii
CHAPTER ONE: INTRODUCTION – – – 1
1.1 Background of the study – – – – – 1
1.2 Aim and Objectives of the Study – – – 4
1.2.1 Aim of the study – – – – – – 4
1.2.2 Objectives of the Study – – – – – 4
1.3 Scope and Limitation – – – – – 5
CHAPTER TWO: LITERATURE REVIEW – – 6
2.1 Ecology and distribution of Chryichthys
nigrodigitatus – – – – – – 6
2.2 Characteristics and Economic Importance of
Chryichthys nigrodigitatus – – – – 7
2.3 Bioaccumulation of heavy metals in fish – – 9
2.4 Heavy metals/Toxicity – – – – – 10
2.4.1 Arsenic – – – – – – – 11
2.4.2 Lead – – – – – – – – 14
2.4.3 Cadmium – – – – – – – 18
2.4.4 Chromium – – – – – – – 20
2.4.5 Iron – – – – – – – – 22
2.4.6 Nickel – – – – – – – 26
2.4.7 Zinc – – – – – – – – 27
CHAPTER THREE: MATERIALS AND METHODS – 28
3.1 Materials – – – – – – – 28
3.2 Method – – – – – – – 29
3.2.1 Study Area – – – – – – – 29
3.2.2 Method of Sample Collection – – – – 30
3.2.3 Preparation of Sample for Analysis – – – 31
3.3 Laboratory Procedures – – – – – 32
3.3.1 Analysis for Iron (Fe) – – – – – 32
3.3.2 Analysis for Cadmium (Cd) – – – – 33
3.3.3 Analysis for Lead (Pb) – – – – – 33
3.3.4 Analysis for Chromium (Cr) – – – – 34
3.3.5 Analysis for Nickel (Ni) – – – – – 34
3.3.6 Analysis for Zinc (Zn) – – – – – 35
CHAPTER FOUR: RESULTS AND DISCUSSION – 37
4.1 Results – – – – – – – 37
4.2 Discussion – – – – – – – 37
CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS– 42
5.1 Conclusion – – – – – – – 42
5.2 Recommendations – – – – – – 42
References
Appendices