ABSTRACT
Water pollution by heavy metal is an emerging problem in both developed and undeveloped countries. This research was carried out to compare the concentration of Ni, As, Fe, Pb, Hg, V, and Cd in Cross River Estuary (Itu River), Qua Iboe River Estuary (Ibeno River) and Imo River Estuary (Eastern Obolo River), AkwaIbom State using UNICAM 629 Atomic Absorption Spectrometer. The concentrations of each heavy metal: Ni (0.424±0.034), As (0.001±0.006), Fe (2.659±0.275), Pb (0.255±0.035), Hg (0.0003±0.0004), V (0.011±0.003), Cd (0.555±0.054). The concentration of heavy metals in Tympanotonosfuscatus were generally higher than the DPR and FMENV permissible limit that is safe for human consumption. Cadmium in the study areas were below the detectable limit. The results revealed that the concentration of heavy metals in Tympanotonosfuscatuswere above the permissible limits given by DPR and FMENV and therefore is unfit and unsafe for human consumption.
TABLE OF CONTENTS
TITLE PAGES
Cover Page
Title Page i
Certification ii
Declaration iii
Dedication iv
Acknowledgement v
Abstract vi
Table of Contents vii
CHAPTER ONE: INTRODUCTION
- Background of Study
1.2 Statement of the Problem
1.3 Significance of Study
1.4 Aim and Objectives
1.4.1: Aim
- Objectives of the Study
1.5 Justification
CHAPTER TWO: LITERATURE REVIEW
2.1. Pathways of Heavy Metals in the Environment
2.2 Sources of Heavy Metals Pollution
2.3 Lead (Pb)
2.4 Nickel (Ni)
2.5 Cadmium (Cd)
2.6 Mercury (Hg)
2.7 Arsenic (As)
2.8 Iron (Fe)
2.9 Vanadium
CHAPTER THREE: MATERIALS AND METHODS
3.1 Description of study area
3.2 Sample Collections (Periwinkle)
3.3 Sample Preparation (periwinkle)
3.4 Digestion procedure
3.5 Heavy Metal Determination and AAS settings
3.6 Statistical Analysis
CHAPTER 4: RESULTS AND DISCUSSION
4.1 Discussion and Result
CHAPTER 5: SUMMARY, CONCLUSION AND RECOMMENDATION
5.1 Summary
5.2 Conclusion
5.2 Recommendation
REFERENCES
CHAPTER ONE
INTRODUCTION
- Background of Study
The pollution of the aquatic environment with heavy metals has become a worldwide problem and of scientific concern because the metals are not degradable and most of them have toxic effects on organisms (MacFarlane and Burchett, 2000; Oronsayeetal., 2010). Heavy metals enter rivers and lakes from a variety of sources that include the rocks and soils directly exposed to surface water, in addition to the discharge of various treated and untreated liquid wastes to the water bodies (APHA, 2005; Alaa and Osman, 2010).examples of heavy metals are Arsenic(As), Cadmium (Cd), Iron (Fe), Vanadium (V), Lead (Pb) Manganese (Mn), Mercury (Hg), Nickel (Ni), and zinc (Zn), that have a particular significance in ecotoxicology, since they are highly persistent (Storelliet al., 2005).
Toxicity is realized when these heavy metal levels are higher than the recommended limit which is different for individual elements in drinking water, organisms in the marine environment as it will be consumed by human. Sources include, Weathering of rocks, a variety of anthropogenic activities that are affected by seasons, increase the concentrations of these heavy metals (Oguzie and Izevbigie, 2009).It is difficult to remove them completely from the environment once they enter into it [APHA 1998, ATSDR 2005]. These metals in the form of inorganic compounds from natural and anthropogenic sources continuously enter the aquatic ecosystem where they could pose serious threat to the food chain.
Periwinkle (Tympanotonosfuscatus), the West African mud creeper is a proso-branch gastropod mollusk with soft bodied and externally covered by hard calcareous shell that is segmented. Tympanotonusfuscatus, commonly known as periwinkle, can also be described as a brackish Gastropod belonging to the family Potamididae. It is small and is characterized by turreted granular and spiny shell with a tapering end. This organism is endemic in Nigeria and West Africa. As part of the fauna of the mangrove community, it occurs mainly in the tidal mudflats of estuarine ecosystems. The genus Tympanotonos comprises of a single species which has two varieties Tympanotonosfuscatus andTympanotonosfuscatus var. radula (Egonmwan, 1983).
Periwinkle (Tympanotonosfuscatus) is a very popular well relished and forms a delicacy in the diets of most riverine communities in Niger delta, as it provides relatively cheap source of animal protein together with its medicinal and nutrient capabilities; its shells can be used for construction purposes, for decoration in art and as a source of calcium in animal feeds, the potential of the organism as a food source is well documented. Despite the numerous benefits derived from Tympanotonosfuscatus,its sustainability is threatened by human activities as a result of urbanization. Humans in quest for development have overtime, reduced the habitat of this organism through land reclamation for housing, crop farming and industries.
The common periwinkle is mainly found on rocky shores in the higher and middle intertidal zone. It sometimes lives in small tide pools. It may also be found in muddyhabitats such as estuaries, and can reach depths of 180 feet. When exposed to either extreme cold or heat while climbing, a periwinkle will withdraw into its shell and start rolling, hoping to hit the water. They are common in intertidal zone of mangrove swamps, estuaries, lagoons, creeks where the substratum is muddy and rich in detritus (Jamaboet al., 2009).
Since they are found in the intertidal area, they could be hand-picked especially during low tide. They are deposit feeders, taking in mud and digesting the detritus and other organic matter in the mud, nature of the bottom deposit; water depth and current are factor that affects their distribution in the coastal area of West Africa (Deekae, 1987). The organism is also very medicinal for cases like endemic goiter due to its iodine content. The calcium, phosphate and iron content also recommend it for pregnant women (Bob-Manuel, 2012).
These important food sources constitute a major part of the diet in the Niger Delta region of Nigeria; however, these organisms may bioaccumulate heavy metals in substantial amount in the tissues over a long time which may be unfavorable to the health of inhabitants of this area that consume them. These metals in the form of inorganic compounds from natural and anthropogenic sources continuously enter the aquatic ecosystem where they could pose serious threat to the food chain. Heavy metals are hazardous to humans because they tend to bioaccumulate in vital organs (Opaluwa, 2012). Heavy metals such as lead, cadmium, chromium and mercury pose a number of health hazards to humans. Humans are exposed to these metals by ingestion (drinking or eating) or inhalation (Abiaobo et al., 2017).
ANALYSIS OF HEAVY METALS CONCENTRATION IN PERIWINKLE TYMPANOTONOS FUSCATUS IN CROSS RIVER ESTUARY ITU RIVER, QUA IBOE RIVER ESTUARY IBENO, AND IMO RIVER ESTUARY IKO RIVER ESTUARY,EASTERN OBOLO,AKWA IBOM STATE,NIGERIA
