TABLE OF CONTENT
CONTENTS PAGE
Title Page – – – – – – – – i
Certification – – – – – – – ii
Dedication – – – – – – – – iii
Acknowledgements – – – – – – iv
Abstract – – – – – – – v
Table of Contents – – – – – – – vi
CHAPTER ONE
- INTRODUCTION – – – – – 1
- Background of the Study – – – – – 1
- Aim and Objectives of the Study – – – 6
- Scope and Limitation of the Study – – – 6
- Definition of Terms – – – – – 7
CHAPTER TWO
- LITERATURE REVIEW – – – – 9
- Description of T. Occidentalis – – – – 9
- Botanical Classification of T. Occidentalis – – 11
- Nutritional Value of T. Occidentalis – – – 12
- Pharmacological activities of T. Occidentalis – 14
- Antioxidant Properties – – – – – 14
- Antidiabetic activity – – – – – 16
- Hematological Activity – – – – – 18
- Anti – cancer activity – – – – – 19
- Anti – inflammatory and analgesic activity – – 20
- Male fertility activity – – – – – 20
- Hepatoprotective property – – – – 21
- Anti – malaria activity – – – – – 22
- Antimicrobial activity – – – – – 24
- Heavy metals – – – – – – 25
- Types of Heavy metals – – – – – 26
- Arsenic – – – – – – – 26
- Lead – – – – – – – – 28
- Aluminium – – – – – – – 30
- Iron – – – – – – – – 33
- Mercury – – – – – – – 35
- Copper – – – – – – – 37
- Zinc – – – – – – – – 38
- Source of Heavy Metals in the soil – – – 39
- Fertilizers – – – – – – – 40
- Pesticides – – – – – – – 41
- Biosolids and Manures – – – – – 42
- Metal mining and milling – – – – 43
- Waste water – – – – – – – 44
- Remediation of Heavy Metals in soil – – – 45
- Description of T. Occidentalis – – – – 9
CHAPTER THREE
- MATERIALS AND METHOD – – – 49
- Materials/Reagents – – – – – 49
- Chemicals used and made – – – – 49
- Preparation of reagents used – – – – 50
- Methods – – – – – – – 51
- Sample collection and preparation – – – 51
- Experimental Design/Treatment – – – – 51
- Analytical Procedure – – – – – 52
- Statistical Analysis – – – – – 54
- Materials/Reagents – – – – – 49
CHAPTER FOUR
- RESULTS AND DISCUSSION – – – 55
- Results – – – – – – – 55
- Discussion – – – – – – – 56
CHAPTER FIVE
- CONCLUSION, RECOMMENDATION AND
SUGGESTION FOR FURTHER STUDIES – 59
- Conclusion – – – – – – – 59
- Recommendation – – – – – – 60
- Suggestion for Further Studies – – – – 60
References
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Metals are substances with high electrical conductivity,malleability, and luster, which voluntarily lose their electrons to form cations. Metals are found naturally in the earth’s crust and their compositions vary among different localities, resulting in spatial variations of surrounding concentrations. The metal distribution in the atmospheres monitored by the properties of the given metal and by various environmental factors (Khlifi & Hamza-Chaffai,2010).
Heavy metals are generally referred to as those metals which possess a specific density of more than 5 g/cm3 and adversely affect the environment and living organisms (Järup, 2003).Environmental pollution has become an extensive and dangerous problem as a consequence of industrial and human activities. Widespread low to high pollution of large areas of agricultural land is a particular problem from indiscriminate sludge discharge from industries, crude oil pollution, and wastes (Ogboi, 2012).
Human activities have dramatically changed the balance of biochemical and geological cycles of many heavy metals. An assessment of environmental risk caused by soil contamination is especially important for agricultural as well as non-cultivated areas due to the fact that metals potentially harmful to human health persist in soils for a relatively long time and may transfer into the food chain in considerable amounts (Radmila et al., 2013). The persistent nature of heavy metals in soil due to their non-biodegradability raises environmental concerns because of the interdependence between plants and animals,including humans in the ecosystem (Agbogidi, 2014).
Leafy vegetables tend to accumulate higher concentrations of metalsin edible tissue compared to fruit. Vegetables can be come contaminated with heavy metals if they are grown on soils contaminated by vehicular exhaust, industrial activities,and other agricultural activities, and their risk to people are of great public concern (Kihampa et al., 2011). Consumption of foods contaminated with heavy metals is a major cause of health problems (Osu and Ogoko, 2014). The levels of heavy metals (lead, cadmium, and copper) were determined in cassava samples from different locations of oil-producing areas of Delta State, Nigeria.The results indicate that the different heavy metals had higher values compared with WHO standard (Athar and Ahmad, 2001). It has been reported that the leaves of the fluted pumpkin plants planted in farmlands far from major roads accumulate significant amounts of such heavy metals as Pb, Ni, Cd, Zn,Mn, and Fe (Uboh et al., 2011).
Telfairia occidentalis (Fluted pumpkin) is a species of cucurbitaceace family in the tropics largely consumed in Nigeria, Ghana, and Sierra Leone. The common names for fluted pumpkin include Ubong in Ibibio and Ugu in Igbo.It is a creeping vegetable that spreads low across the ground with lobed leaves and long twisting tendrils. It is a warm weather crop that grows well in low lands and tolerates elevation of some few meters above the ground. It thrives best in soils rich in organic matter (Uboh et al., 2011).Fluted pumpkin plays important role in human and livestock nutrition. It is a source of protein, oil, minerals, and vitamins. The leaves are low in crude fiber but a rich source of folic acid, calcium, zinc, potassium, cobalt, copper, iron,and vitamins A, C, and K. It also has medicinal values as fluted pumpkin leaves and seeds could be used to increase hematological indices, improve sperm quality, and reduce blood glucose. It is rich in antioxidants, thiamin, riboflavin,and ascorbic acid.
The young shoots and leaves of this vegetable are used in preparation of several delicacies in southernNigeria, including Edikang Ikong Soup (a popular delicacy of the Efiks and Ibibios in Cross River and AkwaIbom States, Nigeria)(Idoho-Umeh and Ogbeibu, 2010). It thrives better in the early part of the rainy season, planted between August and October,and can be grown in a garden. It can survive 3-4 years ifthere is moisture in the soil.It is well known that high industrial and traffic activities contribute high levels of heavy metals to the environments.Plants grown around such areas are likely to absorb these metals either from the soil through the roots or from atmospheric contaminants through the leaves (Fifield and Haina, 1997).
In recent times there has been an increase in industrial and domestic activities in this oil-rich region under investigation.Hence there is need for regular and systematic monitoring of the coastal area, particularly farmlands along the riverbank and some tributaries. Also, based on its persistent and cumulative nature as well as the probability of potential toxicity effects of heavy metals as a result of consumption of leafy vegetables and fruits, there is a need to test and analyze this food item to ensure that the levels of these trace elements meet the agreed international requirements.Fluted pumpkin is exceptionally important farm produce from Niger Delta where limited or no data on heavy metal contents of such highly consumed agricultural produce is unavailable even with an upsurge of industrial and domestic activities in the area (Oladunmi et al., 2013).
